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Proposed Rule2021-11442

Endangered and Threatened Wildlife and Plants; Lesser Prairie-Chicken; Threatened Status With Section 4(d) Rule for the Northern Distinct Population Segment and Endangered Status for the Southern Distinct Population Segment

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Published

June 1, 2021

Issuing agencies

Interior DepartmentFish and Wildlife Service

Abstract

We, the U.S. Fish and Wildlife Service (Service), propose to list two Distinct Population Segments (DPSs) of the lesser prairie- chicken (Tympanuchus pallidicinctus), a grassland bird known from southeastern Colorado, western Kansas, eastern New Mexico, western Oklahoma, and the Texas Panhandle under the Endangered Species Act of 1973, as amended (Act). This determination also serves as our 12-month finding on a petition to list the lesser prairie-chicken. After a review of the best available scientific and commercial information, we find that listing the Southern DPS as endangered is warranted, and that listing the Northern DPS as threatened is warranted. Accordingly, we propose to list the Southern DPS as an endangered species under the Act and the Northern DPS as a threatened species with a rule issued under section 4(d) of the Act ("4(d) rule"). If we finalize this rule as proposed, it will add these two DPSs to the List of Endangered and Threatened Wildlife and extend the Act's protections to them. We also are notifying the public that we have scheduled informational meetings followed by public hearings on the proposed rule.

Full Text

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[Federal Register Volume 86, Number 103 (Tuesday, June 1, 2021)]
[Proposed Rules]
[Pages 29432-29482]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2021-11442]

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Vol. 86

Tuesday,

No. 103

June 1, 2021

Part III

Department of the Interior

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Fish and Wildlife Service

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50 CFR Part 17

Endangered and Threatened Wildlife and Plants; Lesser Prairie-Chicken;
Threatened Status With Section 4(d) Rule for the Northern Distinct
Population Segment and Endangered Status for the Southern Distinct
Population Segment; Proposed Rule

Federal Register / Vol. 86 , No. 103 / Tuesday, June 1, 2021 /
Proposed Rules

[[Page 29432]]

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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

[Docket No. FWS-R2-ES-2021-0015; FF09E21000 FXES11110900000 212]
RIN 1018-BB27

Endangered and Threatened Wildlife and Plants; Lesser Prairie-
Chicken; Threatened Status With Section 4(d) Rule for the Northern
Distinct Population Segment and Endangered Status for the Southern
Distinct Population Segment

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Proposed rule.

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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), propose to
list two Distinct Population Segments (DPSs) of the lesser prairie-
chicken (Tympanuchus pallidicinctus), a grassland bird known from
southeastern Colorado, western Kansas, eastern New Mexico, western
Oklahoma, and the Texas Panhandle under the Endangered Species Act of
1973, as amended (Act). This determination also serves as our 12-month
finding on a petition to list the lesser prairie-chicken. After a
review of the best available scientific and commercial information, we
find that listing the Southern DPS as endangered is warranted, and that
listing the Northern DPS as threatened is warranted. Accordingly, we
propose to list the Southern DPS as an endangered species under the Act
and the Northern DPS as a threatened species with a rule issued under
section 4(d) of the Act (``4(d) rule''). If we finalize this rule as
proposed, it will add these two DPSs to the List of Endangered and
Threatened Wildlife and extend the Act's protections to them. We also
are notifying the public that we have scheduled informational meetings
followed by public hearings on the proposed rule.

DATES: We will accept comments received or postmarked on or before
August 2, 2021. Comments submitted electronically using the Federal
eRulemaking Portal (see ADDRESSES, below) must be received by 11:59
p.m. Eastern Time on the closing date. We must receive requests for a
public hearing, in writing, at the address shown in FOR FURTHER
INFORMATION CONTACT by July 16, 2021.
Public informational meeting and public hearing: We will hold a
public informational session from 5 p.m. to 6 p.m., Central Time,
followed by a public hearing from 6:30 p.m. to 8:30 p.m., Central Time,
on July 8, 2021. We will hold a second public informational session
from 5 p.m. to 6 p.m., Central Time, followed by a public hearing from
6:30 p.m. to 8:30 p.m., Central Time, on July 14, 2021.

ADDRESSES: You may submit comments by one of the following methods:
(1) Electronically: Go to the Federal eRulemaking Portal: <a href="http://www.regulations.gov">http://www.regulations.gov</a>. In the Search box, enter FWS-R2-ES-2021-0015,
which is the docket number for this rulemaking. Then, click on the
Search button. On the resulting page, in the Search panel on the left
side of the screen, under the Document Type heading, check the Proposed
Rule box to locate this document. You may submit a comment by clicking
on ``Comment Now!''
(2) By hard copy: Submit by U.S. mail to: Public Comments
Processing, Attn: FWS-R2-ES-2021-0015, U.S. Fish and Wildlife Service,
MS: PRB/3W, 5275 Leesburg Pike, Falls Church, VA 22041-3803.
We request that you send comments only by the methods described
above. We will post all comments on <a href="http://www.regulations.gov">http://www.regulations.gov</a>. This
generally means that we will post any personal information you provide
us (see Information Requested, below, for more information).
Public informational meeting and public hearing: The public
informational meetings and the public hearings will be held virtually
using the Zoom platform. See Public Hearing, below, for more
information.

FOR FURTHER INFORMATION CONTACT: Debra Bills, Field Supervisor,
Arlington Ecological Services Field Office, 2005 NE Green Oaks Blvd.,
Suite 140, Arlington, TX 76006; telephone 817-277-1129. Persons who use
a telecommunications device for the deaf (TDD) may call the Federal
Relay Service at 800-877-8339.

SUPPLEMENTARY INFORMATION:

Executive Summary

Why we need to publish a rule. Under the Act, if we determine that
a species is an endangered or threatened species throughout all or a
significant portion of its range, we are required to promptly publish a
proposal in the Federal Register and make a determination on our
proposal within 1 year. To the maximum extent prudent and determinable,
we must designate critical habitat for any species that we determine to
be an endangered or threatened species under the Act. Listing a species
as an endangered or threatened species and designation of critical
habitat can only be completed by issuing a rule.
What this document does. We propose the listing of the Northern DPS
of the lesser prairie-chicken as a threatened species with a rule under
section 4(d) of the Act and the Southern DPS of the lesser prairie-
chicken as an endangered species under the Act.
The basis for our action. Under the Act, we may determine that a
species is an endangered or threatened species because of any of five
factors: (A) The present or threatened destruction, modification, or
curtailment of its habitat or range; (B) overutilization for
commercial, recreational, scientific, or educational purposes; (C)
disease or predation; (D) the inadequacy of existing regulatory
mechanisms; or (E) other natural or manmade factors affecting its
continued existence. We make these determinations solely on the basis
of the best scientific and commercial data available after conducting a
review of the status of the species and after taking into account those
efforts being made to protect the species.
We have determined that both the northern and southern parts of the
lesser prairie-chicken's range are discrete and significant under our
DPS Policy and are, therefore, listable entities under the Act. The
Southern DPS consists of the Shinnery Oak Ecoregion in New Mexico and
Texas, and the Northern DPS consists of the Sand Sagebrush Ecoregion,
the Mixed Grass Ecoregion, and the Short Grass/Conservation Reserve
Program (CRP) Ecoregion in Texas, Oklahoma, Colorado, and Kansas. These
two DPSs together encompass the entirety of the lesser prairie-
chicken's range. The primary threat impacting both DPSs is the ongoing
loss of large, connected blocks of grassland and shrubland habitat. The
Southern DPS has low resiliency, redundancy, and representation and is
particularly vulnerable to severe droughts due to being located in the
dryer and hotter southwestern portion of the range. Because the
Southern DPS is currently at risk of extinction, we propose to list it
as endangered.
In the Northern DPS, as a result of habitat loss and fragmentation,
resiliency has been much reduced across two of the ecoregions in the
Northern DPS when compared to historical conditions. However, this DPS
still has redundancy across the three ecoregions and genetic and
environmental representation. We expect habitat loss and fragmentation
across the Northern DPS to continue into the foreseeable future,
resulting in even further reduced resiliency. Because

[[Page 29433]]

the Northern DPS is at risk of extinction in the foreseeable future, we
propose to list it as threatened.
Peer review. In accordance with our joint policy on peer review
published in the Federal Register on July 1, 1994 (59 FR 34270), and
our August 22, 2016, memorandum updating and clarifying the role of
peer review of listing actions under the Act, we sought the expert
opinions of 6 appropriate specialists regarding the species status
assessment (SSA) report. We received responses from 4 specialists,
which informed the proposed listing rule. The purpose of peer review is
to ensure that our listing determinations and 4(d) rules are based on
scientifically sound data, assumptions, and analyses. The peer
reviewers have expertise in the biology, habitat, and threats to the
species.

Information Requested

We intend that any final action resulting from this proposed rule
will be based on the best scientific and commercial data available and
be as accurate and as effective as possible. Therefore, we request
comments or information from other governmental agencies, Native
American Tribes, the scientific community, industry, or any other
interested parties concerning this proposed rule.
We particularly seek comments concerning:
(1) The species' biology, range, and population trends, including:
(a) Biological or ecological requirements of the species, including
habitat requirements for feeding, breeding, and sheltering;
(b) Genetics and taxonomy;
(c) Historical and current range, including distribution patterns;
(d) Historical and current population levels, and current and
projected trends; and
(e) Past and ongoing conservation measures for the species, its
habitat, or both.
(2) Factors that may affect the continued existence of the species,
which may include habitat modification or destruction, overutilization,
disease, predation, the adequacy of existing regulatory mechanisms, or
other natural or manmade factors.
(3) Biological, commercial trade, or other relevant data concerning
any threats (or lack thereof) to this species and existing conservation
measures and regulations that may be addressing those threats.
(4) Additional information concerning the historical and current
status, range, distribution, and population size of this species,
including the locations of any additional populations of this species.
(5) Information on regulations that are necessary and advisable to
provide for the conservation of the Northern DPS of the lesser prairie-
chicken and that the Service can consider in developing a 4(d) rule for
the DPS. In particular, information concerning the extent to which we
should include any of the prohibitions associated with section 9 in the
4(d) rule or whether any other forms of take should be excepted from
the prohibitions in the 4(d) rule.
(6) Information on whether an exception from the prohibitions
associated with section 9 should be included in the 4(d) rule for the
Northern DPS for industry and/or landowner participants who are
enrolled in and operating in compliance with the mitigation framework
included in the Range-Wide Conservation Plan for the Lesser Prairie-
Chicken being administered by the Western Association of Fish and
Wildlife Agencies but who do not have incidental take coverage via the
companion Candidate Conservation Agreement with Assurances covering oil
and gas activities.
(7) Which areas would be appropriate as critical habitat for the
species and why areas should or should not be proposed for designation
as critical habitat in the future, including whether there are threats
to the species from human activity that would be expected to increase
due to the designation and whether that increase in threat would
outweigh the benefit of designation such that the designation of
critical habitat may not be prudent.
(8) Specific information on:
(a) The amount and distribution of habitat for the lesser prairie-
chicken which should be considered for proposed critical habitat;
(b) What may constitute ``physical or biological features essential
to the conservation of the species within the geographical range
currently occupied by the species'';
(c) Where these features are currently found;
(d) Whether any of these features may require special management
considerations or practices;
(e) What areas are currently occupied and contain features
essential to the conservation of the species should be included in the
designation and why; and
(f) What unoccupied areas are essential for the conservation of the
species and why. Please include sufficient information with your
submission (such as scientific journal articles or other publications)
to allow us to verify any scientific or commercial information you
include.
Please note that submissions merely stating support for, or
opposition to, the action under consideration without providing
supporting information, although noted, will not be considered in
making a determination, as section 4(b)(1)(A) of the Act directs that
determinations as to whether any species is an endangered or a
threatened species must be made ``solely on the basis of the best
scientific and commercial data available.''
You may submit your comments and materials concerning this proposed
rule by one of the methods listed in ADDRESSES. We request that you
send comments only by the methods described in ADDRESSES.
If you submit information via <a href="http://www.regulations.gov">http://www.regulations.gov</a>, your
entire submission--including any personal identifying information--will
be posted on the website. If your submission is made via a hardcopy
that includes personal identifying information, you may request at the
top of your document that we withhold this information from public
review. However, we cannot guarantee that we will be able to do so. We
will post all hardcopy submissions on <a href="http://www.regulations.gov">http://www.regulations.gov</a>.
Comments and materials we receive, as well as supporting
documentation we used in preparing this proposed rule, will be
available for public inspection on <a href="http://www.regulations.gov">http://www.regulations.gov</a>.
Because we will consider all comments and information we receive
during the comment period, our final determinations may differ from
this proposal. Based on the new information we receive (and any
comments on that new information), we may conclude that the Southern
DPS is threatened instead of endangered, or that the Northern DPS is
endangered instead of threatened, or we may conclude that either DPS
does not warrant listing as either an endangered species or a
threatened species. In addition, we may change the parameters of the
prohibitions or the exceptions to those prohibitions in the 4(d) rule
for the Northern DPS if we conclude it is appropriate in light of
comments and new information received. For example, we may expand the
incidental-take prohibitions or the exceptions to those prohibitions in
the 4(d) rule for the Northern DPS to include prohibiting additional
activities if we conclude that those additional activities are not
compatible with conservation of the species. Conversely, we may
establish additional exceptions to the incidental-take prohibitions in
the final rule if we conclude that the activities would facilitate or
are compatible with the conservation and recovery of the species.

[[Page 29434]]

List of Acronyms

We use many acronyms in this proposed rule. For the convenience of
the reader, we define some of them here:

ACEC = Area of Critical Environmental Concern
BLM = Bureau of Land Management
CI = confidence interval
CCAA = candidate conservation agreement with assurances
CCA/A = candidate conservation agreement and candidate conservation
agreement with assurances
CPW = Colorado Parks and Wildlife
CRP = Conservation Reserve Program
DPS = Distinct Population Segment
KDWPT = Kansas Department of Wildlife, Parks and Tourism
LPCI = Lesser Prairie-Chicken Initiative
LPN = Listing Priority Number
NRCS = Natural Resources Conservation Service
ODWC = Oklahoma Department of Wildlife Conservation
PFW = the Service's Partners for Fish and Wildlife Program
RMPA = Resource Management Plan Amendment
RWP = Lesser Prairie-Chicken Range-wide Conservation Plan
SSA = Species Status Assessment
TPWD = Texas Parks and Wildlife Department
USFS = U.S. Forest Service
WAFWA = Western Association of Fish and Wildlife Agencies

Previous Federal Actions

In 1973, the Service's Office of Endangered Species published a
list of threatened wildlife of the United States in Resource
Publication 114, often referred to as the ``Red Book.'' While this
publication did not, by itself, provide any special protections, it
served in part to solicit additional information regarding the status
of the identified taxa. The lesser prairie-chicken was one of 70 birds
included in this publication (Service 1973, pp. 134-135), but little
Federal regulatory action occurred on the lesser prairie-chicken until
1995.
On October 6, 1995, we received a petition, dated October 5, 1995,
from the Biodiversity Legal Foundation, Boulder, Colorado, and Marie E.
Morrissey (petitioners). The petitioners requested that we list the
lesser prairie-chicken as threatened throughout its known historical
range in the United States. The petitioners also requested that
critical habitat be designated as soon as the needs of the species are
sufficiently well known. However, from October 1995 through April 1996,
we were under a moratorium on listing actions as a result of Public Law
104-6, which, along with a series of continuing budget resolutions,
eliminated or severely reduced our listing budget through April 1996.
We were unable to act on the petition during that period.
On July 8, 1997 (62 FR 36482), we announced our 90-day finding that
the petition presented substantial information indicating that the
petitioned action may be warranted. We subsequently published our 12-
month finding for the lesser prairie-chicken on June 9, 1998 (63 FR
31400), concluding that the petitioned action was warranted but
precluded by other higher priority listing actions. This 12-month
finding identified the lesser prairie-chicken as a candidate for
listing with a listing priority number (LPN) of 8, indicating that the
magnitude of threats was moderate and the immediacy of the threats to
the species was high.
On January 8, 2001 (66 FR 1295), we published our resubmitted
petition findings for 25 animal species, including the lesser prairie-
chicken, having outstanding ``warranted-but-precluded'' petition
findings as well as notice of one candidate removal. The lesser
prairie-chicken remained a candidate with an LPN of 8 in our October
30, 2001 (66 FR 54808); June 13, 2002 (67 FR 40657); May 4, 2004 (69 FR
24876); May 11, 2005 (70 FR 24870); September 12, 2006 (71 FR 53756);
and December 6, 2007 (72 FR 69034) candidate notices of review. In our
December 10, 2008 (73 FR 75176), candidate notice of review, we changed
the LPN for the lesser prairie-chicken from an 8 to a 2. This change in
LPN reflected a change in the magnitude of the threats from moderate to
high primarily due to an anticipated increase in the development of
wind energy and associated placement of transmission lines throughout
the estimated occupied range of the lesser prairie-chicken. Our
November 9, 2009 (74 FR 57804), November 10, 2010 (75 FR 69222), and
October 26, 2011 (76 FR 66370) candidate notices of review retained an
LPN of 2 for the lesser prairie-chicken.
After making our 12-month finding in 1998, we received several 60-
day notices of intent to sue from WildEarth Guardians (formerly Forest
Guardians) and several other parties for failure to make expeditious
progress toward listing of the lesser prairie-chicken. WildEarth
Guardians subsequently filed suit on September 1, 2010, in the U.S.
District Court for the District of Colorado.
In 2011, the Service entered into a settlement agreement with
WildEarth Guardians that impacted multiple cases nationwide (In re
Endangered Species Act Section 4 Deadline Litigation, No. 10-377 (EGS),
MDL Docket No. 2165 (D.D.C. May 10, 2011)). As relevant to the lesser
prairie-chicken, the agreement required the Service to submit a
proposed listing rule for the lesser prairie-chicken to the Federal
Register for publication by September 30, 2012.
On September 27, 2012, the settlement agreement was modified to
require that the proposed listing rule be submitted to the Federal
Register on or before November 29, 2012. On December 11, 2012, we
published a proposed rule (77 FR 73828) to list the lesser prairie-
chicken as a threatened species under the Act (16 U.S.C. 1531 et seq.).
On May 6, 2013, we announced the publication of a proposed 4(d) rule
under the authority of section 4(d) of the Act (78 FR 26302).
On July 9, 2013, we announced a 6-month extension (78 FR 41022) of
the final listing determination based on our finding that there was
substantial disagreement regarding the sufficiency or accuracy of the
available data relevant to our determination regarding the proposed
listing rule.
On April 10, 2014, we published a final rule listing the lesser
prairie-chicken as a threatened species under the Act (79 FR 19973) and
concurrently published a final 4(d) rule for the lesser prairie-chicken
(79 FR 20073). However, on September 1, 2015, the final listing rule
for the lesser prairie-chicken was vacated by the United States
District Court for the Western District of Texas, which also mooted the
final 4(d) rule. On July 20, 2016, the Service published in the Federal
Register a final rule that removed the lesser prairie-chicken from the
List of Endangered and Threatened Wildlife in accordance with the court
decision (81 FR 47047).
On September 8, 2016, we received a new petition from WildEarth
Guardians, Defenders of Wildlife, and Center for Biological Diversity
to list the lesser prairie-chicken as endangered throughout its entire
range or in three distinct population segments (Molvar 2016, entire).
On November 30, 2016, we published a 90-day petition finding that
concluded that the petition to list the lesser prairie-chicken provided
substantial information that the petitioned action may be warranted (81
FR 86315). On June 12, 2019, the petitioners filed their complaint with
the court alleging the Service failed to complete the 12-month petition
finding for the lesser prairie-chicken. On September 12, 2019, the
Service and the plaintiffs entered into a stipulated settlement
agreement that the Service would submit a 12-month petition finding to
the Federal Register no later than May 26, 2021. This 12-month finding
completes the Service's obligations under that settlement agreement.

[[Page 29435]]

Supporting Documents

An SSA team prepared an SSA report for the lesser prairie-chicken.
The SSA team was composed of Service biologists, in consultation with
other species experts. The SSA report represents a compilation of the
best scientific and commercial data available concerning the status of
the species, including the impacts of past, present, and future factors
(both negative and beneficial) affecting the species. The Service sent
the SSA report to six independent peer reviewers and received four
responses. The Service also sent the SSA report to the five State fish
and wildlife agencies within the range of the lesser prairie-chicken
(Colorado, Kansas, New Mexico, Oklahoma, and Texas) and the four
primary Federal agencies with whom we work to deliver conservation
actions that could benefit the lesser prairie-chicken: The Bureau of
Land Management (BLM), the Natural Resources Conservation Service
(NRCS), Farm Service Agency (FSA), and U.S. Forest Service (USFS).
These partners include scientists with expertise in management of
either the lesser prairie-chicken or the habitat upon which the lesser
prairie-chicken depends. We received responses from USFS, BLM, and all
five of the State wildlife agencies. Comments and feedback from
partners and peer reviewers were incorporated into the SSA report as
appropriate and have informed this proposed rule.

I. Proposed Listing Determination

Background

Below is a summary of the taxonomy, life history, and ecology of
the lesser prairie-chicken; for a thorough review, please see the SSA
report (version 2.2; Service 2021, pp. 5-14).
The lesser prairie-chicken is in the order Galliformes, family
Phasianidae, subfamily Tetraoninae; it is generally recognized as a
species separate from the greater prairie-chicken (Tympanuchus cupido
pinnatus) (Jones 1964, pp. 65-73; American Ornithologist's Union 1998,
p. 122).
Most lesser prairie-chicken adults live for 2 to 3 years and
reproduce in the spring and summer (Service 2021, pp. 10-12). Males
congregate on leks during the spring to attract and mate with females
(Copelin 1963, p. 26; Hoffman 1963, p. 730; Crawford and Bolen 1975, p.
810; Davis et al. 1979, p. 84; Merchant 1982, p. 41; Haukos 1988, p.
49). Male prairie-chickens tend to exhibit strong breeding site
fidelity, often returning to a specific lek many times, even in cases
of declining female attendance and habitat condition (Copelin 1963, pp.
29-30; Hoffman 1963, p. 731; Campbell 1972, pp. 698-699, Hagen et al.
2005, entire, Harju et al. 2010, entire). Females tend to establish
nests relatively close to the lek, commonly within 0.6 to 2.4 mi (1 to
4 km) (Copelin 1963, p. 44; Giesen 1994, p. 97), where they incubate 8
to 14 eggs for 24 to 27 days and then raise broods of young throughout
the summer (Boal and Haukos 2016, p. 4). Some females will attempt a
second nesting if the first nest fails (Johnsgard 1973, pp. 63-64;
Merchant 1982, p. 43; Pitman et al. 2006, p. 25). Eggs and young lesser
prairie-chickens are susceptible to natural mortality from
environmental stress and predation. The appropriate vegetative
community and structure is vital to provide cover for nests and young
and to provide food resources as broods mature into adults (Suminski
1977, p. 32; Riley 1978, p. 36; Riley et al. 1992, p. 386; Giesen 1998,
p. 9). For more detail on habitat needs of the lesser prairie-chicken,
please see the SSA report (Service 2021, pp. 9-14).
The lesser prairie-chicken once ranged across the Southern Great
Plains of Southeastern Colorado, Southwestern Kansas, Western Oklahoma,
the Panhandle and South Plains of Texas, and Eastern New Mexico;
currently, it occupies a substantially reduced portion of its presumed
historical range (Rodgers 2016, p. 15). Estimates of the potential
maximum historical range of the lesser prairie-chicken (e.g., Taylor
and Guthery 1980a, p. 1, based on Aldrich 1963, p. 537; Johnsgard 2002,
p. 32; Playa Lakes Joint Venture 2007, p. 1) range from about 64-115
million acres (ac) (26-47 million hectares (ha)). The more recent
estimate of the historical range of the lesser prairie-chicken
encompasses an area of approximately 115 million ac (47 million ha).
Presumably, not all of the area within this historical range was evenly
occupied by lesser prairie-chicken, and some of the area may not have
been suitable to regularly support lesser prairie-chicken populations
(Boal and Haukos 2016, p. 6). However, the current range of the lesser
prairie-chicken has been significantly reduced from the historical
range at the time of European settlement. Estimates as to extent of the
loss vary from greater than 90 percent reduction (Hagen and Giesen
2005, unpaginated) to approximately 83 percent reduction (Van Pelt et
al. 2013, p. 3).
Lesser prairie-chicken monitoring has been occurring for multiple
decades and have included multiple different methodologies. Estimates
of population abundance prior to the 1960s are indeterminable and rely
almost entirely on anecdotal information (Boal and Haukos 2016, p. 6).
While little is known about precise historical population sizes, the
lesser prairie-chicken was reported to be quite common throughout its
range in the early 20th century (Bent 1932, pp. 280-281, 283; Baker
1953, p. 8; Bailey and Niedrach 1965, p. 51; Sands 1968, p. 454;
Fleharty 1995, pp. 38-44; Robb and Schroeder 2005, p. 13). For example,
prior to 1900, as many as two million birds may have existed in Texas
alone (Litton 1978, p. 1). Information regarding population size is
available starting in the 1960s when the State fish and wildlife
agencies began routine lesser prairie-chicken monitoring efforts.
However, survey methodology and effort have differed over the decades,
making it difficult to precisely estimate trends.
The SSA report and this proposed rule rely on two main population
estimates. The two methodologies largely cover different time periods,
so we report the results of both throughout this proposed rule in order
to give the best possible understanding of lesser prairie-chicken
trends both recently and throughout the past decades.
The first of the two studies used historical lek surveys and
population reconstruction methods to calculate historical trends and
estimate male abundance from 1965 through 2016 (Hagen et al. 2017, pp.
6-9). We have identified concerns in the past with some of the
methodologies and assumptions made in this analysis, and others have
also noted the challenges of using these data for long-term trends (for
example, Zavaleta and Haukos 2013, p. 545; Cummings et al. 2017, pp.
29-30). While these concerns remain, including the very low sample
sizes particularly in the 1960s, this work represents the only attempt
to compile the extensive historical ground lek count data collected by
State agencies to estimate the number of males at both the range-wide
and ecoregional scales, and represents the best available data for
understanding historical population trends.
Following development of aerial survey methods (McRoberts et al.
2011b, entire), the second summary of lesser prairie-chicken population
data uses more statistically rigorous estimates of lesser prairie-
chicken abundance (both males and females). This second study uses data
from aerial line-transect surveys throughout the range of the lesser
prairie-chicken; these results are then extrapolated from the surveyed
area to the rest of the range (Nasman et al. 2020, entire). The results
of these

[[Page 29436]]

survey efforts should not be taken as precise estimates of the annual
lesser prairie-chicken abundance, as indicated by the large confidence
intervals. Thus, we caution the reader not to draw conclusions based
upon annual fluctuations. Instead, we consider the best use of this
data is for long-term trend analysis. Thus, in the SSA Report and this
proposed rule, we report the population estimate for the current
condition as the average of the past 5 years of surveys.
The results of the study using lek data (abundance of males)
indicate that lesser prairie-chicken range-wide abundance (based on a
minimum estimated number of male lesser prairie-chicken at leks) peaked
from 1965-1970 at a mean estimate of about 175,000 males (Figure 1).
The estimated mean population maintained levels of greater than 100,000
males until 1989, after which they steadily declined to a low of 25,000
males in 1997 (Garton et al. 2016, p. 68). The mean population
estimates following 1997 peaked again at about 92,000 males in 2006,
but subsequently declined to 34,440 males in 2012 (Figure 1).
The aerial survey results from 2012 through 2020 (Figure 2)
estimated the lesser prairie-chicken population abundance, averaged
over the most recent 5 years of surveys (2015-2020, no surveys in
2019), at 27,384 (90% confidence interval: 15,690, 59,981) (Nasman et
al. 2020, p. 21; Table 3.3).
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The preferred habitat of the lesser prairie-chicken is mixed-grass
prairies and shrublands, with the exception of the Short-Grass/CRP
Ecoregion where shrubs play a lesser role. Lesser prairie-chickens
appear to select areas having a shrub component dominated by sand
sagebrush or sand shinnery oak when those areas are available
(Donaldson 1969, pp. 56, 62; Taylor and Guthery 1980a, p. 6; Giesen
1998, pp. 3-4). In the southern and central portions of the lesser
prairie-chicken range, small shrubs, such as sand shinnery oak, have
been reported to be important for summer shade (Copelin 1963, p. 37;
Donaldson 1969, pp. 44-45, 62), winter protection, and as supplemental
foods (Johnsgard 1979, p. 112), while in the Short-Grass/CRP Ecoregion,
stands of grass that provide adequate vegetative structure likely serve
the same roles. The absence of anthropogenic features as well as other
vertical structures is important, as lesser prairie-chickens tend to
avoid using areas with trees, vertical structures, and other
disturbances in areas with otherwise adequate habitat conditions (Braun
et al. 2002, pp. 11-13; Pruett et al. 2009, pp. 1256, 1258; Hovick et
al. 2014a, p. 1685; Boggie et al. 2017, entire; Lautenbach 2017, pp.
104-142; Plumb et al. 2019, entire).
At the population scale, the most important requirement for the
lesser prairie-chicken is having large, intact, ecologically diverse
grasslands to complete their life history and maintain healthy
populations (Fuhlendorf et al. 2017b, entire). Historically, these
ecologically diverse grasslands and shrublands were maintained by the
occurrence of wildfires (keeping woody vegetation restricted to
drainages and rocky outcroppings) and by grazing by bison and other
large ungulates. The lesser prairie-chicken is a species that is area-
sensitive; that is, it requires large, intact grasslands for functional
self-sustaining populations (Giesen 1998, pp. 3-4; Bidwell et al. 2002,
pp. 1-3; Hagen et al. 2004, pp. 71, 76-77; Haukos and Zavaleta 2016, p.
107).
The lesser prairie-chicken now occurs within four ecoregions
(Figure 3); these ecoregions were originally delineated in 2012 as part
of the aerial survey designed to monitor long-trends in lesser prairie-
chicken populations. Each ecoregion is associated with unique
environmental conditions based on habitat and climatic variables and
some genetic differentiation (Boal and Haukos 2016, p. 5; Oyler-McCance
et al. 2016, p. 653). These four ecoregions are the Short-Grass
Prairie/CRP Mosaic Ecoregion in Kansas; the Sand Sagebrush Prairie
Ecoregion in Colorado, Kansas, and Oklahoma; the Mixed-Grass Prairie
Ecoregion in Kansas, Texas, and Oklahoma; and the Sand Shinnery Oak
Prairie Ecoregion of New Mexico and Texas.

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The Shinnery Oak Ecoregion occupies portions of eastern New Mexico
and the South Plains of Texas (McDonald et al. 2012, p. 2). It has a
variable vegetation community that contains a mix of shrubs such as
sand shinnery oak (Quercus havardii) and sand sagebrush (Artemisia
filifolia) as well as mixed and tall grasses and forbs (Grisham et al.
2016a, p. 317). The mean population estimate ranged between about 5,000
to 12,000 males through 1980, increased to 20,000 males in the mid-
1980s and declined to ~1,000 males in 1997 (Hagen et al. 2017 pp. 6-9).
The mean population estimate peaked again to ~15,000 males in 2006 and
then declined again to fewer than 3,000 males in the mid-2010s. While
population estimates for the Shinnery Oak Ecoregion have varied over
recent years, the most recent surveys estimate a 5-year average
population size of 3,077 birds (90% confidence intervals (CI): 170,
8,237). Approximately 11 percent of all lesser prairie-chicken occur in
this ecoregion (Service 2021, pp. 66-78). Lesser prairie-chicken from
the Shinnery Oak Ecoregion are genetically distinct and geographically
isolated from the other three ecoregions by 95 miles (mi) (153
kilometers (km)) (Figure 3; Oyler-McCance et al. 2016, p. 653).
With the exception of lesser prairie-chicken areas owned by the
State Game Commission and federally owned BLM lands in New Mexico, the
majority of the Shinnery Oak Ecoregion is privately owned (Grisham et
al. 2016a, p. 315). Nearly all of the area in the Texas portion of the
ecoregion is privately owned and managed for agricultural use and
petroleum production (Haukos 2011, p. 110). The remaining patches of
shinnery oak prairie have become isolated, relict communities because
the surrounding grasslands have been

[[Page 29438]]

converted to row crop agriculture or fragmented by oil and gas
exploration and urban development (Peterson and Boyd 1998, p. 22).
Additionally, honey mesquite (Prosopis glandulosa) encroachment within
this ecoregion has played a significant role in decreasing available
space for the lesser prairie-chicken. Technological advances in
irrigated row crop agriculture have led to more recent conversion of
shinnery oak prairie habitat to row crops in Eastern New Mexico and
West Texas (Grisham et al. 2016a, p. 316).
The Sand Sagebrush Ecoregion occurs in Southeast Colorado,
Southwest Kansas, and a small portion of Western Oklahoma (McDonald et
al. 2012, p. 2). The vegetation community in this area primarily
consists of sand sagebrush and the associated mixed and tall grass
species that are usually found in the sandier soils adjacent to rivers,
streams, and other drainages in the area. Lesser prairie-chicken from
the Sand Sagebrush Ecoregion form a distinct genetic cluster from other
ecoregions but have likely contributed some individuals to the Short-
Grass/CRP Ecoregion through dispersal (Oyler-McCance et al. 2016, p.
653).
Historically, the Sand Sagebrush Ecoregion supported the highest
density of lesser prairie-chicken and was considered the core of the
lesser prairie-chicken range (Haukos et al. 2016, p. 282). A single
flock detected in Seward County, Kansas, was estimated to potentially
contain more than 15,000 birds (Bent 1932, p. 281). The population size
is estimated to have peaked at more than 85,000 males in the 1970s
(Garton et al. 2016, p. 62) and has been in decline since the late
1970s. More recent survey efforts estimate a 5-year average population
size of 1,215 birds (90% CI: 196, 4,547). Less than 5 percent of all
lesser prairie-chicken occur in this ecoregion (Service 2021, pp. 66-
78). Most of the decline has been attributed to habitat deterioration
and conversion of sand sagebrush to intensive row crop agriculture due
to an increase in center pivot irrigation (Jensen et al. 2000, p. 172).
Environmental conditions in this ecoregion can be extreme, with
stochastic events such as blizzards negatively impacting lesser
prairie-chicken populations.
The Short-Grass/CRP Ecoregion falls within the mixed- and short-
grass prairies of Central and Western Kansas (McDonald et al. 2012, p.
2). As the name implies, much of this ecoregion historically consisted
of short-grass prairie interspersed with mixed-grass prairie as well as
sand sagebrush prairie along some drainages (Dahlgren et al. 2016, p.
260). By the 1980s, large expanses of prairies had been converted from
native grass for crop production in this ecoregion. After the
introduction of the CRP in 1985, landowners began to have enhanced
incentives to convert croplands to perennial grasslands to provide
cover for the prevention of soil erosion. The State of Kansas required
those enrolling in the CRP to plant native mixed- and tall-grass
species, which is notable because the grasses in this area historically
consisted largely of short-grass species, which generally do not
provide adequate habitat for the lesser prairie-chicken. For more
information on the CRP, see the SSA report (Service 2021, pp. 52-54).
Prior to the late 1990s, lesser prairie-chickens in this ecoregion
were thought to be largely absent (or occurred sporadically in low
densities) (Hagen and Giesen 2005, unpaginated; Rodgers 1999, p. 19).
We do not know what proportion of the eastern Short-Grass/CRP Ecoregion
in Kansas was historically occupied by lesser prairie-chicken (Hagen
2003, pp. 3-4), and surveys in this ecoregion only began in earnest in
1999 (Dahlgren et al. 2016, p. 262). The CRP is an idle lands program,
which requires establishment of grass cover and precludes tillage or
agricultural commodity production for the duration of the contract, and
has contractual limits to the type, frequency, and timing of management
activities, such as burning, haying, or grazing of the established
grasses. As a result of these factors, CRP often provides the
vegetative structure preferentially used by lesser prairie-chickens for
nesting. In the State of Kansas, the availability of CRP lands,
especially CRP lands with interseeded or original seed mixture of
forbs, resulted in increased habitat availability for the lesser
prairie-chicken and, thus, an expansion of the known lesser prairie-
chicken range and an increase in the abundance of the lesser prairie-
chicken (Rodgers 1999, pp. 18-19; Fields 2004, pp. 11, 105; Fields et
al. 2006, pp. 931, 937; Sullins et al. 2018, p. 1617).
The Short-Grass/CRP Ecoregion is now estimated to contain the
majority of lesser prairie-chickens compared to the other ecoregions,
with recent survey efforts estimating a 5-year average population size
of 16,957 birds (90% CI: 13,605, 35,350), representing approximately 62
percent of the rangewide population (Service 2021, pp. 66-78). Recent
genetic studies indicate that lesser prairie-chickens have moved
northward largely from the Mixed-Grass Ecoregion and, to a lesser
extent, the Sand Sagebrush Ecoregion into the Short-Grass/CRP Ecoregion
(Oyler-McCance et al. 2016, p. 653).
The northern section of this ecoregion is the only portion of the
lesser prairie-chicken's range where co-occurrence with greater
prairie-chicken occurs. Hybridization rates of up to 5 percent have
been reported (Pitman 2013, p. 5), and that rate seemed to be stable
across multiple years, though sampling is limited where the species co-
occur (Pitman 2013, p. 12). Limited additional work has been completed
to further assess the rate of hybridization. There are concerns about
the implications of genetic introgression (dilution) of lesser prairie-
chicken genes, particularly given that potential effects are poorly
understood (Dahlgren et al. 2016, p. 276). Unresolved issues include
whether hybridization reduces fitness, alters behavior or morphological
traits in either a positive or negative way and the historical
occurrence and rate of hybridization.
The Mixed-Grass Ecoregion for the lesser prairie-chicken lies in
the northeastern panhandle of Texas, the panhandle of northwestern
Oklahoma, and south-central Kansas (McDonald et al. 2012, p. 2). The
Mixed-Grass Ecoregion is separated from the Short-Grass/CRP Ecoregion
in Kansas by the Arkansas River. The vegetation community in this
ecoregion consists largely of a mix of perennial grasses and shrubs
such as sand sagebrush, sand plum (Prunus angustifolia), yucca (Yucca
spp.), and sand shinnery oak (Wolfe et al. 2016, p. 300). Based upon
population reconstruction data, the mean population estimate was around
30,000 males in the 1970s and 1980s followed by a decline in the 1990s
(Hagen et al. 2016, pp. 6-7). The mean population estimate peaked again
in the early 2000s at around 25,000 males, before declining to and
remaining at its lowest levels, <10,000 males since 2012 (Hagen et al.
2016, pp. 6-7). Although historical population estimates in the
ecoregion reported some of the highest densities of lesser prairie-
chicken in the range (Wolfe et al. 2016, p. 299), recent aerial survey
efforts estimate a 5-year average population size of 6,135 birds
(including males and females; 90% CI: 1,719, 11,847). The recent survey
work estimates about 22 percent of lesser prairie-chicken occur in this
ecoregion (Service 2021, pp. 66-78). Lesser prairie-chicken from the
Mixed-Grass Ecoregion are similar in genetic variation with the Short-
Grass/CRP Ecoregion, with individuals likely dispersing from the Mixed-
Grass Ecoregion to the Short-Grass/CRP Ecoregion (Oyler-McCance et al.
2016, p. 653).

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Distinct Population Segment Evaluation

Under the Act, the term species includes ``any subspecies of fish
or wildlife or plants, and any distinct population segment of any
species of vertebrate fish or wildlife which interbreeds when mature.''
16 U.S.C. 1532(16). To guide the implementation of the distinct
population segment (DPS) provisions of the Act, we and the National
Marine Fisheries Service (National Oceanic and Atmospheric
Administration--Fisheries), published the Policy Regarding the
Recognition of Distinct Vertebrate Population Segments Under the
Endangered Species Act (DPS Policy) in the Federal Register on February
7, 1996 (61 FR 4722). Under our DPS Policy, we use two elements to
assess whether a population segment under consideration for listing may
be recognized as a DPS: (1) The population segment's discreteness from
the remainder of the species to which it belongs, and (2) the
significance of the population segment to the species to which it
belongs. If we determine that a population segment being considered for
listing is a DPS, then the population segment's conservation status is
evaluated based on the five listing factors established by the Act to
determine if listing it as either endangered or threatened is
warranted.
As described in Previous Federal Actions, we were petitioned to
list the lesser prairie-chicken either rangewide or in three distinct
population segments. The petition suggested three DPS configurations:
(1) Shinnery Oak Ecoregion, (2) the Sand Sagebrush Ecoregion, and (3) a
segment including the Mixed-Grass Ecoregion and the Short-Grass/CRP
Ecoregion. The petition also combined the Sand Sagebrush Ecoregion, the
Mixed-Grass Ecoregion, and the Short-Grass/CRP Ecoregion due to
evidence they are linked genetically and geographically (Molver 2016,
p. 18). Genetic studies indicate that lesser prairie-chicken from the
Mixed-Grass Ecoregion are similar in genetic variation with the Short-
Grass/CRP Ecoregion, with individuals likely dispersing from the Mixed-
Grass Ecoregion to the Short-Grass/CRP Ecoregion (Oyler-McCance et al.
2016, p. 653). Other genetic data indicate that lesser prairie-chicken
from the Sand Sagebrush Ecoregion and lesser prairie-chicken from the
Mixed-Grass and Short-Grass/CRP Ecoregion also share genetic traits.
Genetic studies of neutral markers indicate that, although lesser
prairie-chicken from the Sand Sagebrush Ecoregion form a distinct
genetic cluster from other ecoregions, they have also likely
contributed some individuals to the Short-Grass/CRP Ecoregion through
dispersal (Oyler-McCance et al. 2016, p. 653). Additionally, these
three ecoregions are not geographically isolated from one another
(Figure 3). As a result of the shared genetic characteristics and the
geographic connections, we have concluded the Sand Sagebrush Ecoregion,
the Mixed-Grass Ecoregion, and the Short-Grass/CRP Ecoregion are
appropriately considered as one potential DPS configuration.
Under the Act, we have the authority to consider for listing any
species, subspecies, or, for vertebrates, any distinct population
segment (DPS) of these taxa if there is sufficient information to
indicate that such action may be warranted. We considered whether two
segments meet the DPS criteria under the Act: The southernmost
ecoregion (Shinnery Oak) and a segment containing the three
northernmost ecoregions (Mixed-Grass, Short-Grass/CRP, and Sand
Sagebrush).
Discreteness
Under our DPS Policy, a population segment of a vertebrate taxon
may be considered discrete if it satisfies either of the following
conditions: (1) It is markedly separated from other populations of the
same taxon as a consequence of physical, physiological, ecological, or
behavioral factors. Quantitative measures of genetic or morphological
discontinuity may provide evidence of this separation; or (2) it is
delimited by international governmental boundaries within which
differences in control of exploitation, management of habitat,
conservation status, or regulatory mechanisms exist that are
significant in light of section 4(a)(1)(D) of the Act.
We conclude the two segments satisfy the ``markedly separate''
conditions. The two groups of ecoregions are not separated from each
other by international governmental boundaries. The southernmost
ecoregion (Shinnery Oak) is separated from the three northern
ecoregions by approximately 95 mi (153 km), much of which is developed
or otherwise unsuitable habitat. There has been no recorded movement of
lesser prairie-chickens between the Shinnery Oak Ecoregion and the
three northern ecoregions over the past several decades. Because there
is no connection between the two parts of the range, there is
subsequently no gene flow between them (Oyler-McCance et al. 2016,
entire).
Therefore, we have determined that both the southern ecoregion and
the northern three ecoregions of the lesser prairie-chicken range both
individually meet the condition for discreteness under our DPS Policy.
Significance
Under our DPS Policy, once we have determined that a population
segment is discrete, we consider its biological and ecological
significance to the larger taxon to which it belongs. This
consideration may include, but is not limited to: (1) Evidence of the
persistence of the discrete population segment in an ecological setting
that is unusual or unique for the taxon, (2) evidence that loss of the
population segment would result in a significant gap in the range of
the taxon, (3) evidence that the population segment represents the only
surviving natural occurrence of a taxon that may be more abundant
elsewhere as an introduced population outside its historical range, or
(4) evidence that the discrete population segment differs markedly from
other populations of the species in its genetic characteristics.
For the lesser prairie-chicken, we first considered evidence that
the discrete population segment differs markedly from other populations
of the species in its genetic characteristics. The most recent
rangewide genetic study examined neutral markers in the four ecoregions
where the lesser prairie-chicken occurs. It concluded that there is
significant genetic variation across the lesser prairie-chicken range.
The study also concluded that although there is genetic exchange
between the three northern ecoregions (particularly movement of birds
northward from the Mixed-Grass Ecoregion to the Short-Grass/CRP
Ecoregion, and, to a lesser extent, from the Sand Sagebrush Ecoregion
into the Short-Grass/CRP Ecoregion), lesser prairie-chicken from the
Shinnery Oak Ecoregion in the southwestern part of the range are a
group that is genetically distinct from the remainder of the range
(Oyler-McCance et al. 2016, p. 653). The Shinnery Oak Ecoregion is more
distinct from all three ecoregions in the Northern DPS than those
ecoregions are from each other (Oyler-McCance et al. 2016, Table 4).
The Shinnery Oak Ecoregion was likely historically connected to the
remainder of the range, but the two parts have been separated since
approximately the time of European settlement. Therefore, the two
segments of the range are genetically distinct from each other.
We next considered evidence that loss of the population segment
would result in a significant gap in the range of the taxon. As
discussed above, the southwestern and northeastern parts of the range
are separated by

[[Page 29440]]

approximately 95 mi (153 km). The loss of the Shinnery Oak Ecoregion
would result in the loss of the entire southwestern part of the
species' range and decrease species redundancy and ecological and
genetic representation, thus decreasing its ability to withstand
demographic and environmental stochasticity. The loss of the other
three ecoregions would result in the loss of 75 percent of the species'
range, as well as loss of the part of the range (the Short-Grass/CRP
Ecoregion) which has recently experienced a northward expansion of
occupied habitat. This would create a large gap in the northeastern
portion of the species range, also reducing the species' ability to
withstand demographic and environmental stochasticity. Therefore, the
loss of either part of the range would result in a significant gap in
the range of the lesser prairie-chicken. These genetic differences and
the evidence that a significant gap in the range of the taxon would
result from the loss of either discrete population segment both
individually satisfy the significance criterion of the DPS Policy.
Therefore, under the Service's DPS Policy, we find that both the
southern and northern segments of the lesser prairie-chicken are
significant to the taxon as a whole.
Distinct Population Segment Conclusion
Our DPS Policy directs us to evaluate the significance of a
discrete population in the context of its biological and ecological
significance to the remainder of the species to which it belongs. Based
on an analysis of the best available scientific and commercial data, we
conclude that the northern and southern parts of the lesser prairie-
chicken range are discrete due to geographic (physical) isolation from
the remainder of the taxon. Furthermore, we conclude that both parts of
the lesser prairie-chicken range are significant, because loss of
either part would result in a significant gap in the range of the
taxon, and because the two parts of the range are markedly separate
based on neutral genetic markers. Therefore, we conclude that both the
northern and southern parts of the lesser prairie-chicken range are
both discrete and significant under our DPS Policy and are, therefore,
uniquely listable entities under the Act.
Based on our DPS Policy (61 FR 4722; February 7, 1996), if a
population segment of a vertebrate species is both discrete and
significant relative to the taxon as a whole (i.e., it is a distinct
population segment), its evaluation for endangered or threatened status
will be based on the Act's definition of those terms and a review of
the factors enumerated in section 4(a) of the Act. Having found that
both parts of the lesser prairie-chicken range meet the definition of a
distinct population segment, we evaluate the status of both the
Southern DPS and the Northern DPS of the lesser prairie-chicken to
determine whether either meets the definition of an endangered or
threatened species under the Act. The line demarcating the break
between the Northern and Southern DPS lies approximately half-way
between the two DPSs in the unoccupied area between them (Figure 4).
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[[Page 29442]]

Regulatory and Analytical Framework

Regulatory Framework
Section 4 of the Act (16 U.S.C. 1533) and its implementing
regulations (50 CFR part 424) set forth the procedures for determining
whether a species is an endangered species or a threatened species. The
Act defines an endangered species as a species that is ``in danger of
extinction throughout all or a significant portion of its range,'' and
a threatened species as a species that is ``likely to become an
endangered species within the foreseeable future throughout all or a
significant portion of its range.'' The Act requires that we determine
whether any species is an ``endangered species'' or a ``threatened
species'' because of any of the following factors:
(A) The present or threatened destruction, modification, or
curtailment of its habitat or range;
(B) Overutilization for commercial, recreational, scientific, or
educational purposes;
(C) Disease or predation;
(D) The inadequacy of existing regulatory mechanisms; or
(E) Other natural or manmade factors affecting its continued
existence.
These factors represent broad categories of natural or human-caused
actions or conditions that could have an effect on a species' continued
existence. In evaluating these actions and conditions, we look for
those that may have a negative effect on individuals of the species, as
well as other actions or conditions that may ameliorate any negative
effects or may have positive effects.
We use the term ``threat'' to refer in general to actions or
conditions that are known to or are reasonably likely to negatively
affect individuals of a species. The term ``threat'' includes actions
or conditions that have a direct impact on individuals (direct
impacts), as well as those that affect individuals through alteration
of their habitat or required resources (stressors). The term ``threat''
may encompass--either together or separately--the source of the action
or condition or the action or condition itself.
However, the mere identification of any threat(s) does not
necessarily mean that the species meets the statutory definition of an
``endangered species'' or a ``threatened species.'' In determining
whether a species meets either definition, we must evaluate all
identified threats by considering the expected response by the species
and the effects of the threats--in light of those actions and
conditions that will ameliorate the threats--on an individual,
population, and species level. We evaluate each threat and its expected
effects on the species, then analyze the cumulative effect of all of
the threats on the species as a whole. We also consider the cumulative
effect of the threats in light of those actions and conditions that
will have positive effects on the species, such as any existing
regulatory mechanisms or conservation efforts. The Secretary determines
whether the species meets the definition of an ``endangered species''
or a ``threatened species'' only after conducting this cumulative
analysis and describing the expected effect on the species now and in
the foreseeable future.
The Act does not define the term ``foreseeable future,'' which
appears in the statutory definition of ``threatened species.'' Our
implementing regulations at 50 CFR 424.11(d) set forth a framework for
evaluating the foreseeable future on a case-by-case basis. The term
``foreseeable future'' extends only so far into the future as the
Services can reasonably determine that both the future threats and the
species' responses to those threats are likely. In other words, the
foreseeable future is the period of time in which we can make reliable
predictions. ``Reliable'' does not mean ``certain''; it means
sufficient to provide a reasonable degree of confidence in the
prediction. Thus, a prediction is reliable if it is reasonable to
depend on it when making decisions.
It is not always possible or necessary to define foreseeable future
as a particular number of years. Analysis of the foreseeable future
uses the best scientific and commercial data available and should
consider the timeframes applicable to the relevant threats and to the
species' likely responses to those threats in view of its life-history
characteristics. Data that are typically relevant to assessing the
species' biological response include species-specific factors such as
lifespan, reproductive rates or productivity, certain behaviors, and
other demographic factors.
Analytical Framework
The SSA report documents the results of our comprehensive
biological review of the best scientific and commercial data regarding
the status of the species, including an assessment of the potential
threats to the species. The SSA report does not represent a decision by
the Service on whether the species should be proposed for listing as an
endangered or threatened species under the Act. It does, however,
provide the scientific basis that informs our regulatory decisions,
which involve the further application of standards within the Act and
its implementing regulations and policies. The following is a summary
of the key results and conclusions from the SSA report; the full SSA
report can be found on <a href="http://www.regulations.gov">http://www.regulations.gov</a> at Docket FWS-R2-ES-
2021-0015.
To assess lesser prairie-chicken viability, we used the three
conservation biology principles of resiliency, redundancy, and
representation (Shaffer and Stein 2000, pp. 306-310). Briefly,
resiliency supports the ability of the species to withstand
environmental and demographic stochasticity (for example, wet or dry,
warm or cold years), redundancy supports the ability of the species to
withstand catastrophic events (for example, droughts, large pollution
events), and representation supports the ability of the species to
adapt over time to long-term changes in the environment (for example,
climate changes). In general, the more resilient and redundant a
species is and the more representation it has, the more likely it is to
sustain populations over time, even under changing environmental
conditions. Using these principles, we identified the species'
ecological requirements for survival and reproduction at the
individual, population, and species levels, and described the
beneficial and risk factors influencing the species' viability.
The SSA process can be categorized into three sequential stages.
During the first stage, we evaluated the individual species' life-
history needs. The next stage involved an assessment of the historical
and current condition of the species' demographics and habitat
characteristics, including an explanation of how the species arrived at
its current condition. The final stage of the SSA involved making
predictions about the species' responses to positive and negative
environmental and anthropogenic influences that are likely to occur in
the future. Throughout all of these stages, we used the best available
information to characterize viability as the ability of a species to
sustain populations in the wild over time. We use this information to
inform our regulatory decision.
The SSA report does not assess the distinct population segments
proposed for the species because the SSA focuses on the biological
factors, rather than those, such as DPS, that are created by the
regulatory framework of the Act. Both the geospatial and threats
analysis in the SSA report are summarized by ecoregion. In this
proposed rule, we present the analyses per ecoregion from the SSA
report but also summarize per DPS as applicable.

[[Page 29443]]

Summary of Biological Status and Threats

In this discussion, we review the biological condition of the
species and its resources, and the threats that influence the species'
current and future condition, in order to assess the species' overall
viability and the risks to that viability.
We note that, by using the SSA framework to guide our analysis of
the scientific information documented in the SSA report, we have not
only analyzed individual effects on the species, but we have also
analyzed their potential cumulative effects. We incorporate the
cumulative effects into our SSA analysis when we characterize the
current and future condition of the species. To assess the current and
future condition of the species, we undertake an iterative analysis
that encompasses and incorporates the threats individually and then
accumulates and evaluates the effects of all the factors that may be
influencing the species, including threats and conservation efforts.
Because the SSA framework considers not just the presence of the
factors, but to what degree they collectively influence risk to the
entire species, our assessment integrates the cumulative effects of the
factors and replaces a standalone cumulative effects analysis.
Representation
To evaluate representation as a component of lesser prairie-chicken
viability, we considered the need for multiple healthy lesser prairie-
chicken populations within each of the four ecoregions to conserve the
genetic and ecological diversity of the lesser prairie-chicken. Each of
the four ecoregions varies in terms of vegetative communities and
environmental conditions, resulting in differences in abundance and
distribution and management strategies (Boal and Haukos 2016, p. 5).
Despite reduced range and population size, most lesser prairie-chicken
populations appear to have maintained comparatively high levels of
neutral genetic variation (DeYoung and Williford 2016, p. 86). As
discussed in Significance above, recent genetic studies also show
significant genetic variation across the lesser prairie-chicken range
based on neutral markers (Service 2021, Figure 2.4), which supports
management separation of these four ecoregions and highlights important
genetic differences between them (Oyler-McCance et al. 2016, p. 653).
While it is unknown how this genetic variation relates to differences
in adaptive capacity between the ecoregions, maintaining healthy lesser
prairie-chicken populations across this range of diversity increases
the likelihood of conserving inherent ecological and genetic variation
within the species to enhance its ability for adaptation to future
changes in environmental conditions.
Resiliency
In the case of the lesser prairie-chicken, we considered the
primary indicators of resiliency to be habitat availability, population
abundance, growth rates, and quasi-extinction risk. Lesser prairie-
chicken populations within ecoregions must have sufficient habitat and
population growth potential to recover from natural disturbance events
such as extensive wildfires, extreme hot or cold events, extreme
precipitation events, or extended local periods of below-average
rainfall. These events can be particularly devastating to populations
when they occur during the late spring or summer when nesting and brood
rearing are occurring and individuals are more susceptible to
mortality.
The lesser prairie-chicken is considered a ``boom-bust'' species
based on its high reproductive potential with a high degree of annual
variation in rates of successful reproduction and recruitment. These
variations are largely driven by the influence of seasonal
precipitation patterns (Grisham et al. 2013, pp. 6-7), which impact the
population through effects on the quality of habitat. Periods of below-
average precipitation and higher spring/summer temperatures result in
less appropriate grassland vegetation cover and less food available,
resulting in decreased reproductive output (bust periods). Periods with
above-normal precipitation and cooler spring/summer temperatures will
support favorable lesser prairie-chicken habitat conditions and result
in high reproductive success (boom periods). In years with particularly
poor weather conditions, individual female lesser prairie-chicken may
forgo nesting for the year. This population characteristic highlights
the need for habitat conditions to support large population growth
events during favorable climatic conditions so they can withstand the
declines during poor climatic conditions without a high risk of
extirpation.
Historically, the lesser prairie-chicken had large expanses of
grassland habitat to maintain populations. Early European settlement
and development of the Southern Great Plains for agriculture initially,
and for energy extraction later, substantially reduced the amount and
connectivity of the grasslands of this region. Additionally, if
historically some parts of the range were drastically impacted or
eliminated due to a stochastic event, that area could be reestablished
from other populations. Today, those characteristics of the grasslands
have been degraded, resulting in the loss and fragmentation of
grasslands in the Southern Great Plains. Under present conditions, the
potential lesser prairie-chicken habitat is limited to small,
fragmented grassland patches (relative to historical conditions)
(Service 2021, pp. 64-78). The larger and more intact the remaining
grassland patches are, with appropriate vegetation structure, the
larger, healthier, and more resilient the lesser prairie-chicken
populations will be. Exactly how large habitat patches should be to
support healthy populations depends on the quality and intactness of
the patches. Recommended total space needed for persistence of lesser
prairie-chicken populations ranges from a minimum of about 12,000 ac
(4,900 ha) (Davis 2005, p. 3) up to more than 50,000 ac (20,000 ha) to
support single leks, depending on the quality and intactness of the
area (Applegate and Riley 1998, p. 14; Haufler et al. 2012, pp. 7-8;
Haukos and Zavaleta 2016, p. 107).
A single lesser prairie-chicken lek is not considered a population
that can persist on its own. Instead, complexes of multiple leks that
interact with each other are required for a lesser prairie-chicken
population to be persistent over time. These metapopulation dynamics,
in which individuals interact on the landscape to form larger
populations, are dependent upon the specific biotic and abiotic
landscape characteristics of the site and how those characteristics
influence space use, movement, patch size, and fragmentation (DeYoung
and Williford 2016, pp. 89-91). Maintaining multiple, highly resilient
populations (complexes of leks) within the four ecoregions that have
the ability to interact with each other will increase the probability
of persistence in the face of environmental fluctuations and stochastic
events. Because of this concept of metapopulations and their influence
on long-term persistence, when evaluating lesser prairie-chicken
populations, site-specific information can be informative. However,
many of the factors affecting lesser prairie-chicken populations should
be analyzed at larger spatial scales (Fuhlendorf et al. 2002, entire).
Redundancy
Redundancy describes the ability of a species to withstand
catastrophic events. Catastrophes are stochastic

[[Page 29444]]

events that are expected to lead to population collapse regardless of
population health and for which adaptation is unlikely. Redundancy
spreads the risk and can be measured through the duplication and
distribution of resilient populations that are connected across the
range of the species. The larger the number of highly resilient
populations the lesser prairie-chicken has, distributed over a large
area within each ecoregion, the better the species can withstand
catastrophic events. Catastrophic events for lesser prairie-chicken
might include extreme drought; widespread, extended droughts; or a
disease outbreak.
Measuring redundancy for lesser prairie-chicken is a difficult task
due to the physiological and biological characteristics of the species,
which make it difficult to survey and limit the usefulness of survey
results. To estimate redundancy for the lesser prairie-chicken, we
estimated the geographic distribution of predicted available habitat
within each of the four ecoregions and the juxtaposition of that
habitat to other habitat and non-habitat. As the amount of large
grassland patches decreases and grassland patches become more isolated
to reduce or preclude lesser prairie-chicken movement between them, the
overall redundancy of the species is reduced. As redundancy decreases
within any representative ecoregion or DPS, the likelihood of
extirpation within that ecoregion increases. As large grassland
patches, the connectivity of those patches, and the number of lesser
prairie-chicken increase, so does the redundancy within an ecoregion or
a DPS.
Current Condition
In the SSA report, we assessed the current condition of the lesser
prairie-chicken through an analysis of existing habitat; a review of
factors that have impacted the species in the past, including a
geospatial analysis to estimate areas of land cover impacts on the
current landscape condition; a summary of the current potential usable
area based upon our geospatial analysis; and a summary of past and
current population estimates. We also evaluated and summarized the
benefit of the extensive conservation efforts that are ongoing
throughout the lesser prairie-chicken range to conserve the species and
its habitat.
Geospatial Analysis Summary
The primary concern for the lesser prairie-chicken is habitat loss
and fragmentation. We conducted a geographic information system (GIS)
analysis to analyze the extent of usable land cover changes and
fragmentation within the range of the lesser prairie-chicken,
characterizing landscape conditions spatially to analyze the ability of
those landscapes to support the biological needs of the lesser prairie-
chicken. Impacts included in this analysis were the direct and indirect
effects of areas that were converted to cropland; encroached by woody
vegetation such as mesquite and eastern red cedar (Juniperus
virginiana); and developed for roads, petroleum production, wind
energy, and transmission lines. We acknowledge that there are other
impacts, such as power lines or incompatible grazing on the landscape,
that can affect lesser prairie-chicken habitat. For those impacts,
either no geospatial data were available, or the available data would
have added so much complexity to our geospatial model that the results
would have been uninterpretable or not explanatory for our purpose.
There are several important limitations to our geospatial analysis.
First, it is a landscape-level analysis, so the results only represent
broad trends at the ecoregional and rangewide scales. Secondly, this
analysis does not incorporate different levels of habitat quality, as
the data do not exist at the spatial scale or resolution needed. Our
analysis only considers areas as either potentially usable or not
usable by lesser prairie-chicken based upon land cover classifications.
We recognize that some habitat, if managed as high-quality grassland,
may have the ability to support higher densities of lesser prairie-
chicken than other habitat that exists at lower qualities.
Additionally, we also recognize that some areas of land cover that we
identified as suitable could be of such poor quality that it is of
limited value to the lesser prairie-chicken. We recognize there are
many important limitations to this landscape analysis, including
variation and inherent error in the underlying data and unavailable
data. We interpreted the results of this analysis with those
limitations in mind.
In this proposed rule, we discuss effects that relate to the total
potential usable unimpacted acreage for lesser prairie-chicken, as
defined by our geospatial analysis (hereafter, analysis area). A
complete description of the purpose, methodology, constraints, and
additional details for this analysis is provided in the SSA report for
the lesser prairie-chicken (Service 2021, Appendix B, Parts 1, 2, and
3).
Threats Influencing Current Condition
Following are summary evaluations of the threats analyzed in the
SSA report for the lesser prairie-chicken: Effects associated with
habitat degradation, loss, and fragmentation, including conversion of
grassland to cropland (Factor A), petroleum production (Factor A), wind
energy development and transmission (Factor A), woody vegetation
encroachment (Factor A), and roads and electrical distribution lines
(Factor A); other factors, such as livestock grazing (Factor A), shrub
control and eradication (Factor A), collision mortality from fences
(Factor E), predation (Factor C), influence of anthropogenic noise
(Factor E), fire (Factor A); and extreme weather events (Factor E). We
also evaluate existing regulatory mechanisms (Factor D) and ongoing
conservation measures.
In the SSA report, we also considered three additional threats:
Hunting and other recreational, educational, and scientific use (Factor
B); parasites and diseases (Factor C); and insecticides (Factor E). We
concluded that, as indicated by the best available scientific and
commercial information, these threats are currently having little to no
impact on lesser prairie-chickens and their habitat, and thus their
overall effect now and into the future is expected to be minimal.
Therefore, we will not present summary analyses of those threats in
this document but will consider them in our overall conclusions of
impacts to the species. For full descriptions of all threats and how
they impact the species, please see the SSA report (Service 2021, pp.
24-49).
Habitat Degradation, Loss, and Fragmentation
The grasslands of the Great Plains are among the most threatened
ecosystems in North America (Samson et al. 2004, p. 6) and have been
impacted more than any other major ecosystem on the continent (Samson
and Knopf 1994, p. 418). Temperate grasslands are also one of the least
conserved ecosystems (Hoekstra et al. 2005, p. 25). Grassland loss in
the Great Plains is estimated at approximately 70 percent (Samson et
al. 2004, p. 7), with nearly 93,000 square km (23 million ac; 9.3
million ha) of grasslands in the United States lost between 1982 and
1997 alone (Samson et al. 2004, p. 9). The vast majority of the lesser
prairie-chicken range (>95 percent) occurs on private lands that have
been in some form of agricultural production since at least the early
1900s. As a result, available habitat for grassland species, such as
the lesser

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prairie-chicken, has been much reduced and fragmented compared to
historical conditions across its range.
Habitat impacts occur in three general categories that often work
synergistically at the landscape scale: Degradation, loss, and
fragmentation. Habitat degradation results in changes to a species'
habitat that reduces its suitability to the species, but without making
the habitat entirely unsuitable. Degradation may result in lower
carrying capacity, lower reproductive potential, higher predation
rates, or other effects. Habitat loss may result from the same
anthropogenic sources that cause degradation, but the habitat has been
altered to the point where it has no suitability for the species at
all. Habitat fragmentation occurs when habitat loss is patchy and
leaves a matrix of grassland habitat behind. While habitat degradation
continues to be a concern, we focus our analysis on habitat loss and
fragmentation from the cumulative effects of multiple sources of
activities as the long-term drivers of the species' viability.
Initially, reduction in the total area of available habitat may be
more significant than fragmentation and can exert a much greater effect
on populations (Fahrig 1997, pp. 607, 609). However, as habitat loss
continues, the effects of fragmentation often compound effects of
habitat loss and produce even greater population declines than habitat
loss alone (Bender et al. 1998, pp. 517-518, 525). Spatial habitat
fragmentation occurs when some form of disturbance, usually habitat
degradation or loss, results in the separation or splitting apart of
larger, previously contiguous, functional components of habitat into
smaller, often less valuable, noncontiguous patches (Wilcove et al.
1986, p. 237; Johnson and Igl 2001, p. 25; Franklin et al. 2002,
entire). Habitat loss and fragmentation influence habitat availability
and quality in three primary ways: (1) Total area of available habitat
constrains the maximum population size for an area; (2) the size of
habitat patches within a larger habitat area, including edge effects
(changes in population or community structures that occur at the
boundary of two habitats), influences habitat quality and size of local
populations; and (3) patch isolation influences the amount of species
movement between patches, which constrains demographic and genetic
exchange and ability to recolonize local areas where the species might
be extirpated (Johnson and Igl 2001, p. 25; Stephens et al. 2003, p.
101).
Habitat loss, fragmentation, and degradation correlate with the
ecological concept of carrying capacity. Within any given block or
patch of lesser prairie-chicken habitat, carrying capacity is the
maximum number of birds that can be supported indefinitely by the
resources available within that area, that is, sufficient food,
shelter, and lekking, nesting, brood-rearing, and wintering areas. As
habitat loss increases and the size of an area decreases, the maximum
number of birds that can inhabit that particular habitat patch also
decreases. Consequently, a reduction in the total area of available
habitat can negatively influence biologically important characteristics
such as the amount of space available for establishing territories and
nest sites (Fahrig 1997, p. 603). Over time, the continued conversion
and loss of habitat will reduce the capacity of the landscape to
support historical population levels, causing a decline in population
sizes.
Habitat loss not only contributes to overall declines in usable
area for a species but also causes a reduction in the size of
individual habitat patches and influences the proximity and
connectivity of these patches to other patches of similar habitat
(Stephens et al. 2003, p. 101; Fletcher 2005, p. 342), reducing rates
of movement between habitat patches until, eventually, complete
isolation results. Habitat quality for many species is, in part, a
function of patch size and declines as the size of the patch decreases
(Franklin et al. 2002, p. 23). Both the size and shape of the habitat
patch have been shown to influence population persistence in many
species (Fahrig and Merriam 1994, p. 53). The size of the fragment can
influence reproductive success, survival, and movements. As the
distances between habitat fragments increase, the rate of dispersal
between the habitat patches may decrease and ultimately cease, reducing
the likelihood of population persistence and potentially leading to
both localized and regional extinctions (Harrison and Bruna 1999, p.
226; With et al. 2008, p. 3153). In highly fragmented landscapes, once
a species becomes extirpated from an area, the probability of
recolonization is greatly reduced (Fahrig and Merriam 1994, p. 52).
For the lesser prairie-chicken, habitat loss can occur due to
either direct or indirect habitat impacts. Direct habitat loss is the
result of the removal or alteration of grasslands, making that space no
longer available for use by the lesser prairie-chicken. Indirect
habitat loss and degradation is when the vegetation still exists, but
the areas adjacent to a disturbance (the disturbance can be natural or
manmade) are no longer used by lesser prairie-chicken, are used at
reduced rates, or the disturbance negatively alters demographic rates
or behavior in the affected area. In many cases, as discussed in detail
below for specific disturbances, the indirect habitat loss can greatly
exceed the direct habitat loss.
Primarily due to their site fidelity and the need for large,
ecologically diverse landscapes, lesser prairie-chickens appear to be
relatively intolerant to habitat alteration, particularly for
activities that fragment habitat into smaller patches. The birds
require habitat patches with large expanses of vegetative structure in
different successional stages to complete different phases in their
life cycle, and the loss or partial loss of even one of these
structural components can significantly reduce the overall value of
that habitat to lesser prairie-chickens (Elmore et al. 2013, p. 4). In
addition to the impacts on the individual patches, as habitat loss and
fragmentation increases on the landscape, the juxtaposition of habitat
patches to each other and to non-habitat areas will change. This
changing pattern on the landscape can be complex and difficult to
predict, but the results, in many cases, are increased isolation of
individual patches (either due to physical separation or barriers
preventing or limiting movement between patches) and direct impacts to
metapopulation structure, which could be important for population
persistence (DeYoung and Williford 2016, pp. 88-91).
The following sections provide a discussion and quantification of
the influence of habitat loss and fragmentation on the grasslands of
the Great Plains within the lesser prairie-chicken analysis area and
more specifically allow us to characterize the current condition of
lesser prairie-chicken habitat.
Conversion of Grassland to Cropland
Historical conversion of grassland to cultivated agricultural lands
in the late 19th century and throughout the 20th century has been
regularly cited as an important cause in the rangewide decline in
abundance and distribution of lesser prairie-chicken populations
(Copelin 1963, p. 8; Jackson and DeArment 1963, p. 733; Crawford and
Bolen 1976a, p. 102; Crawford 1980, p. 2; Taylor and Guthery 1980b, p.
2; Braun et al. 1994, pp. 429, 432-433; Mote et al. 1999, p. 3).
Because cultivated grain crops may have provided increased or more
dependable winter food supplies for lesser prairie-chickens (Braun et
al. 1994, p. 429), the

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initial conversion of smaller patches of grassland to cultivation may
have been temporarily beneficial to the short-term needs of the species
as primitive and inefficient agricultural practices made grain
available as a food source (Rodgers 2016, p. 18). However, as
conversion increased, it became clear that landscapes having greater
than 20 to 37 percent cultivated grains may not support stable lesser
prairie-chicken populations (Crawford and Bolen 1976a, p. 102). More
recently, abundances of lesser prairie-chicken increased with
increasing cropland until a threshold of 10 percent was reached; after
that, abundance of lesser prairie-chicken declined with increasing
cropland cover (Ross et al. 2016b, entire). While lesser prairie-
chicken may forage in agricultural croplands, croplands do not provide
for the habitat requirements of the species life cycle (cover for
nesting and thermoregulation); thus, lesser prairie-chicken avoid
landscapes dominated by cultivated agriculture, particularly where
small grains are not the dominant crop (Crawford and Bolen 1976a, p.
102).
As part of the geospatial analysis completed for the SSA, we
estimated the amount of cropland that currently exists in the four
ecoregions of the lesser prairie-chicken. These percentages do not
equate to the actual proportion of habitat loss in the analysis area
because not all of the analysis area was necessarily suitable lesser
prairie-chicken habitat; they are only the estimated portion of the
total analysis area converted from the native vegetation community to
cropland. About 37 percent of the total area in the Short-Grass/CRP
Ecoregion; 32 percent of the total area in the Sand Sagebrush
Ecoregion; 13 percent of the total area in the Mixed-Grass Ecoregion;
and 14 percent of the total area in the Shinnery Oak Ecoregion of
grassland have been converted to cropland in the analysis area of the
lesser prairie-chicken. Rangewide, we estimate about 4,963,000 ac
(2,009,000 ha) of grassland have been converted to cropland,
representing about 23 percent of the total analysis area. We note that
these calculations do not account for all conversion that has occurred
within the historical range of the lesser prairie-chicken but are
limited to the amount of cropland within our analysis area. For further
information, including total acreages impacted, see the SSA report for
the lesser prairie-chicken (Service 2021 Appendix E and Figure E.1).
The effects of grassland converted to cropland within the
historical range of the lesser prairie-chicken have significantly
impacted the amount of habitat available and how fragmented the
remaining habitat is for the lesser prairie-chicken, leading to overall
decreases in resiliency and redundancy throughout the range of the
lesser prairie-chicken. The impact of cropland has shaped the
historical and current condition of the grasslands and shrublands upon
which the lesser prairie-chicken depends.
Petroleum and Natural Gas Production
Petroleum and natural gas production has occurred over much of the
estimated historical and current range of the lesser prairie-chicken.
As demand for energy has continued to increase nationwide, so has oil
and gas development in the Great Plains. In Texas, for example, active
oil and gas wells in the lesser prairie-chicken occupied range have
increased by more than 80 percent over the previous decade (Timmer et
al. 2014, p. 143). The impacts from oil and gas development extend
beyond the immediate well sites; they involve activities such as
surface exploration, exploratory drilling, field development, and
facility construction, as well as access roads, well pads, and
operation and maintenance. Associated facilities can include compressor
stations, pumping stations, and electrical generators.
Petroleum and natural gas production result in both direct and
indirect habitat effects to the lesser prairie-chicken (Hunt and Best
2004, p. 92). Well pad construction, seismic surveys, access road
development, power line construction, pipeline corridors, and other
activities can all result in direct habitat loss by removal of
vegetation used by lesser prairie-chickens. As documented in other
grouse species, indirect habitat loss also occurs from avoidance of
vertical structures, noise, and human presence (Weller et al. 2002,
entire), which all can influence lesser prairie-chicken behavior in the
general vicinity of oil and gas development areas. These activities
also disrupt lesser prairie-chicken reproductive behavior (Hunt and
Best 2004, p. 41).
Anthropogenic features, such as oil and gas wells, affect the
behavior of lesser prairie-chickens and alter the way in which they use
the landscape (Hagen et al. 2011, pp. 69-73; Pitman et al. 2005,
entire; Hagen 2010, entire; Hunt and Best 2004, pp. 99-104; Plumb et
al. 2019, pp. 224-227; Sullins et al. 2019, pp. 5-8; Peterson et al.
2020, entire). Please see the SSA report for a detailed summary of the
best available scientific information regarding avoidance distances and
effects of oil and gas development on lesser prairie-chicken habitat
use (Service 2021, pp. 27-28).
As part of the geospatial analysis discussed in the SSA report, we
calculated the amount of usable land cover for the lesser prairie-
chicken that has been impacted (both direct and indirect impacts) by
oil and natural gas wells in the current analysis area of the lesser
prairie-chicken, though this analysis did not include all associated
infrastructure as those data were not available. We used an impact
radius of 984 ft (300 m) for indirect effects of oil and gas wells.
These calculations were limited to the current analysis area and do not
include historical impacts of habitat loss that occurred outside of the
current analysis area. Thus, the calculation likely underestimates the
rangewide effects of historical oil and gas development on the lesser
prairie-chicken. About 4 percent of the total area in the Short-Grass/
CRP Ecoregion; 5 percent of the total area in the Sand Sagebrush
Ecoregion; about 10 percent of the total area in the Mixed-Grass
Ecoregion; and 4 percent of the total area in the Shinnery Oak
Ecoregion of space that was identified as potential usable or potential
restorable areas have been impacted due to oil and gas development in
the current analysis area of the lesser prairie-chicken. Rangewide, we
estimate about 1,433,000 ac (580,000 ha) of grassland have been lost
due to oil and gas development representing about 7 percent of the
total analysis area. Maps of these areas in each ecoregion are provided
in the SSA report (Service 2021, Appendix E, Figure E.2).
Oil and gas development directly removes habitat that supports
lesser prairie-chicken, and the effects of the development extend past
the immediate site of the wells and their associated infrastructure,
further impacting habitat and altering behavior of lesser prairie-
chicken throughout both the Northern and the Southern DPS. These
activities have resulted in decreases in population resiliency and
species redundancy.
Wind Energy Development and Power Lines
Wind power is a form of renewable energy increasingly being used to
meet current and projected future electricity demands in the United
States. Much of the new wind energy development is likely to come from
the Great Plains States because they have high wind resource potential,
which exerts a strong, positive influence on the amount of wind energy
developed within a particular State (Staid and Guikema 2013, p. 384).
In 2019, three of the five States within the lesser prairie-chicken
range (Colorado, New Mexico, and Kansas) were within the top 10 States

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nationally for fastest growing States for wind generation in the past
year (AWEA 2020, p. 33). There is substantial information (Southwest
Power Pool 2020) indicating interest by the wind industry in developing
wind energy within the range of the lesser prairie-chicken, especially
if additional transmission line capacity is constructed. As of May
2020, approximately 1,792 wind turbines were located within the lesser
prairie-chicken analysis area (Hoen et al. 2020). Not all areas within
the analysis area are habitat for the lesser prairie-chicken, so not
all turbines located within the analysis area affect the lesser
prairie-chicken and its habitat.
The average size of installed wind turbines and all other size
aspects of wind energy development continues to increase (Department of
Energy (DOE) 2015, p. 63; AWEA 2020, p. 87-88; AWEA 2014, entire; AWEA
2015, entire; AWEA 2016, entire; AWEA 2017, entire; AWEA 2018, entire;
AWEA 2019, entire; AWEA 2020, entire). Wind energy developments range
from 20 to 400 towers, each supporting a single turbine. The individual
permanent footprint of a single turbine unit, about 0.75-1 ac (0.3-0.4
ha), is relatively small in comparison with the overall footprint of
the entire array (DOE 2008, pp. 110-111). Roads are necessary to access
the turbine sites for installation and maintenance. Depending on the
size of the wind energy development, one or more electrical
substations, where the generated electricity is collected and
transmitted on to the power grid, may also be built. Considering the
initial capital investment and that the service life of a single
turbine is at least 20 years (DOE 2008, p. 16), we expect most wind
energy developments to be in place for at least 30 years. Repower of
existing wind energy developments at the end of their service life is
increasingly common, with 2,803 MW of operating projects partially
repowering in 2019 (AWEA 2020, p. 2).
Please see the SSA report for a detailed review of the best
available scientific information regarding the potential effects of
wind energy development on habitat use by the lesser prairie-chicken
(Service 2021, pp. 31-33).
Noise effects to prairie-chickens have been recently explored as a
way to evaluate potential negative effects of wind energy development.
For a site in Nebraska, wind turbine noise frequencies were documented
at less than or equal to 0.73 kHz (Raynor et al. 2017, p. 493), and
reported to overlap the range of lek-advertisement vocalization
frequencies of lesser prairie-chicken, 0.50-1.0 kHz. Female greater
prairie-chickens avoided wooded areas and row crops but showed no
response in space use based on wind turbine noise (Raynor et al. 2019,
entire). Additionally, differences in background noise and signal-to-
noise ratio of boom chorus of leks in relation to distance to turbine
have been documented, but the underlying cause and response needs to be
further investigated, especially since the study of wind energy
development noise on grouse is almost unprecedented (Whalen et al.
2019, entire).
The effects of wind energy development on the lesser prairie-
chicken must also take into consideration the influence of the
transmission lines critical to distribution of the energy generated by
wind turbines. Transmission lines can traverse long distances across
the landscape and can be both above ground and underground, although
the vast majority of transmission lines are erected above ground. Most
of the impacts to lesser prairie-chicken associated with transmission
lines are with the above ground systems. Support structures vary in
height depending on the size of the line. Most high-voltage power line
towers are 98 to 125 ft (30 to 38 m) high but can be higher if the need
arises. Local distribution lines, if erected above ground, are usually
much shorter in height but still contribute to fragmentation of the
landscape.
The effect of the transmission line infrastructure is typically
much larger than the physical footprint of transmission line
installation. Transmission lines can indirectly lead to alterations in
lesser prairie-chicken behavior and space use (avoidance), decreased
lek attendance, and increased predation on lesser prairie-chicken.
Transmission lines, particularly due to their length, can be a
significant barrier to dispersal of prairie grouse, disrupting
movements to feeding, breeding, and roosting areas. Both lesser and
greater prairie-chickens avoided otherwise usable habitat near
transmission lines and crossed these power lines much less often than
nearby roads, suggesting that power lines are a particularly strong
barrier to movement (Pruett et al. 2009, pp. 1255-1257). Because lesser
prairie-chicken avoid tall vertical structures like transmission lines
and because transmission lines can increase predation rates, leks
located in the vicinity of these structures may see reduced attendance
by new males to the lek, as has been reported for sage-grouse (Braun et
al. 2002, pp. 11-13). Decreased probabilities of use by lesser prairie-
chicken were shown with the occurrence of more than 0.09 mi (0.15 km)
of major roads, or transmission lines within a 1.2-mi (2-km) radius
(Sullins et al. 2019, unpaged). Additionally, a recent study
corroborated numerous authors' (Pitman et al. 2005; Pruett et al. 2009;
Hagen et al. 2011; Grisham et al. 2014; Hovick et al. 2014a) findings
of negative effects of power lines on prairie grouse and reported a
minimum avoidance distance of 1,925.8 ft (587 m), which is similar to
other studies of lesser prairie-chickens (Plumb et al. 2019, entire).
As part of our geospatial analysis, we calculated the amount of
otherwise usable land cover for the lesser prairie-chicken that has
been impacted (both direct and indirect impacts) by wind energy
development in the current analysis area of the lesser prairie-chicken.
We used an impact radii of 5,906 ft (1,800 m) for indirect effects of
wind turbines and 2,297 ft (700 m) for indirect effects of transmission
lines. Within our analysis area, the following acreages have been
identified as impacted due to wind energy development: About 2 percent
of the total area in the Short-Grass/CRP, Mixed-Grass, and Shinnery Oak
Ecoregions; and no impacts of wind energy development documented
currently within the Sand Sagebrush Ecoregion. Rangewide, we estimate
about 428,000 ac (173,000 ha) of grassland have been impacted by wind
energy development, representing about 2 percent of the total analysis
area (Service 2021, Appendix E, Figure E.3). These percentages do not
account for overlap that may exist with other features that may have
already impacted the landscape.
Additionally, according to our geospatial analysis, the following
acreages within the analysis area have been directly or indirectly
impacted due to the construction of transmission lines: About 7 percent
of the total area in the Short-Grass/CRP Ecoregion; 5 percent of the
total area in the Sand Sagebrush Ecoregion; 7 percent of the total area
in the Mixed-Grass Ecoregion; and 10 percent of the total area in the
Shinnery Oak Ecoregion. Rangewide, we estimate about 1,553,000 ac
(629,000 ha) of grassland have been impacted by transmission lines
representing about 7 percent of the total analysis area (Service 2021,
Appendix E, Figure E.4).
Wind energy development and transmission lines remove habitat that
supports lesser prairie-chicken. The effects of the development extend
past the immediate site of the turbines and their associated
infrastructure, further impacting habitat and altering behavior of
lesser prairie-chicken throughout

[[Page 29448]]

both the Northern and the Southern DPSs. These activities have resulted
in decreases in population resiliency and species redundancy.
Woody Vegetation Encroachment
As discussed in Background, habitat selected by lesser prairie-
chicken is characterized by expansive regions of treeless grasslands
interspersed with patches of small shrubs (Giesen 1998, pp. 3-4);
lesser prairie-chicken avoid areas with trees and other vertical
structures. Prior to extensive Euro-American settlement, frequent fires
and grazing by large, native ungulates helped confine trees like
eastern red cedar to river and stream drainages and rocky outcroppings.
The frequency and intensity of these disturbances directly influenced
the ecological processes, biological diversity, and patchiness typical
of Great Plains grassland ecosystems (Collins 1992, pp. 2003-2005;
Fuhlendorf and Smeins 1999, pp. 732, 737).
Following Euro-American settlement, increasing fire suppression
combined with government programs promoting eastern red cedar for
windbreaks, erosion control, and wildlife cover facilitated the
expansion of eastern red cedar distribution in grassland areas (Owensby
et al. 1973, p. 256; DeSantis et al. 2011, p. 1838). Once a grassland
area has been colonized by eastern red cedar, the trees are mature
within 6 to 7 years and provide a plentiful source of seed so that
adjacent areas can readily become infested with eastern red cedar.
Despite the relatively short viability of the seeds (typically only one
growing season), the large cone crop, potentially large seed dispersal
ability, and the physiological adaptations of eastern red cedar to
open, relatively dry sites help make the species a successful invader
of grassland landscapes (Holthuijzen et al. 1987, p. 1094). Most trees
are relatively long-lived and, once they become established in
grassland areas, require intensive management to remove to return areas
to a grassland state.
Within the southern- and westernmost portions of the estimated
historical and occupied ranges of lesser prairie-chicken in Eastern New
Mexico, Western Oklahoma, and the South Plains and Panhandle of Texas,
honey mesquite is another common woody invader within these grasslands
(Riley 1978, p. vii; Boggie et al. 2017, entire). Mesquite is a
particularly effective invader in grassland habitat due to its ability
to produce abundant, long-lived seeds that can germinate and establish
in a variety of soil types and moisture and light regimes (Lautenbach
et al. 2017, p. 84). Though not as widespread as mesquite or eastern
red cedar, other tall, woody plants, such as redberry or Pinchot
juniper (Juniperus pinchotii), black locust (Robinia pseudoacacia),
Russian olive (Elaeagnus angustifolia), and Siberian elm (Ulmus pumila)
can also be found in grassland habitat historically and currently used
by lesser prairie-chicken and may become invasive in these areas.
Invasion of grasslands by opportunistic woody species causes
otherwise usable grassland habitat to no longer be used by lesser
prairie-chicken and contributes to the loss and fragmentation of
grassland habitat (Lautenbach 2017, p. 84; Boggie et al. 2017, p. 74).
In Kansas, lesser prairie-chicken are 40 times more likely to use areas
that had no trees than areas with 1.6 trees per ac (5 trees per ha),
and no nests occur in areas with a tree density greater than 0.8 trees
per ac (2 trees per ha), at a scale of 89 ac (36 ha) (Lautenbach 2017,
pp. 104-142). Similarly, within the Shinnery Oak Ecoregion, lesser
prairie-chicken space use in all seasons is altered in the presence of
mesquite, even at densities of less than 5 percent canopy cover (Boggie
et al. 2017, entire). Woody vegetation encroachment also contributes to
indirect habitat loss and increases habitat fragmentation because
lesser prairie-chicken are less likely to use areas adjacent to trees
(Boggie et al. 2017, pp. 72-74; Lautenbach 2017, pp. 104-142).
Fire is often the best method to control or preclude tree invasion
of grassland. However, to some landowners and land managers, burning of
grassland can be perceived as a high-risk activity because of the
potential liability of escaped fire impacting nontarget lands and
property. Additionally, it is undesirable for optimizing cattle
production and is likely to create wind erosion or ``blowouts'' in
sandy soils. Consequently, wildfire suppression is common, and
relatively little prescribed burning occurs on private land. Often,
prescribed fire is employed only after significant tree invasion has
already occurred and landowners consider forage production for cattle
to have diminished. Preclusion of woody vegetation encroachment on
grasslands of the southern Great Plains using fire requires
implementing fire at a frequency that mimics historical fire
frequencies of 2-14 years (Guyette et al. 2012, p. 330), further
limiting the number of landowners able to implement fire in a manner
that would truly preclude future encroachment. Additionally, in areas
where grazing pressure is heavy and fuel loads are reduced, a typical
grassland fire may not be intense enough to eradicate eastern red cedar
(Briggs et al. 2002a, p. 585; Briggs et al. 2002b, p. 293; Bragg and
Hulbert 1976, p. 19) and will not eradicate mesquite.
As part of our geospatial analysis, we calculated the amount of
woody vegetation encroachment in the current analysis area of the
lesser prairie-chicken. These calculations of the current analysis area
do not include historical impacts of habitat loss that occurred outside
of the current analysis area; thus, it likely underestimates the
effects of historical woody vegetation encroachment rangewide on the
lesser prairie-chicken. An additional limitation associated with this
calculation is that available remote sensing data lack the ability to
detect areas with low densities of encroachment, as well as areas with
shorter trees; thus, this calculation likely underestimates lesser
prairie-chicken habitat loss due to woody vegetation encroachment. The
identified areas of habitat impacted by woody vegetation are: About 5
percent of the total area in the Short-Grass/CRP Ecoregion; about 2
percent of the total area in the Sand Sagebrush Ecoregion; about 24
percent of the total area in the Mixed-Grass Ecoregion; and about 17
percent of the total area in the Shinnery Oak Ecoregion. Rangewide, we
estimate about 3,071,000 ac (1,243,000 ha) of grassland have been
directly or indirectly impacted by the encroachment of woody
vegetation, or about 18 percent of the total area. These percentages do
not account for overlap that may exist with other features that may
have already impacted the landscape. Further information, including
total acres impacted, is available in the SSA report (Service 2021,
Appendix B; Appendix E, Figure E.5).
Woody vegetation encroachment is contributing to ongoing habitat
loss as well as contributing to fragmentation and degradation of
remaining habitat patches. The effects of woody vegetation encroachment
are particularly widespread in the Shinnery Oak Ecoregion that makes up
the Southern DPS as well as the Mixed-Grass Ecoregion of the Northern
DPS. While there are ongoing efforts to control woody vegetation
encroachment, the current level of woody vegetation on the landscape is
evidence that removal efforts are being outpaced by rates of
encroachment, thus we expect that this threat will continue to
contribute to habitat loss and fragmentation, which has reduced
population resiliency

[[Page 29449]]

across the range of the lesser prairie-chicken.
Roads and Electrical Distribution Lines
Roads and distribution power lines are linear features on the
landscape that contribute to loss and fragmentation of lesser prairie-
chicken habitat and fragment populations as a result of behavioral
avoidance. Lesser prairie-chickens are less likely to use areas close
to roads (Plumb et al. 2019, entire; Sullins et al. 2019, entire).
Additionally, roads contribute to lek abandonment when they disrupt
important habitat features (such as affecting auditory or visual
communication) associated with lek sites (Crawford and Bolen 1976b, p.
239). Some mammal species that prey on lesser prairie-chicken, such as
red fox (Vulpes vulpes), raccoons (Procyon lotor), and striped skunks
(Mephitis mephitis), have greatly increased their distribution by
dispersing along roads (Forman and Alexander 1998, p. 212; Forman 2000,
p. 33; Frey and Conover 2006, pp. 1114-1115).
Traffic noise from roads may indirectly impact lesser prairie-
chicken. Because lesser prairie-chicken depend on acoustical signals to
attract females to leks, noise from roads, oil and gas development,
wind turbines, and similar human activity may interfere with mating
displays, influencing female attendance at lek sites and causing young
males not to be drawn to the leks. Within a relatively short period,
leks can become inactive due to a lack of recruitment of new males to
the display grounds. For further discussion on noise, please see
Influence of Anthropogenic Noise.
Depending on the traffic volume and associated disturbances, roads
also may limit lesser prairie-chicken dispersal abilities. Lesser
prairie-chickens avoid areas of usable habitat near roads (Pruett et
al. 2009, pp. 1256, 1258; Plumb et al. 2019, entire) and in areas where
road densities are high (Sullins et al. 2019, p. 8). Lesser prairie-
chickens are thought to avoid major roads due to disturbance caused by
traffic volume and perhaps to avoid exposure to predators that may use
roads as travel corridors. However, the extent to which roads
constitute a significant obstacle to lesser prairie-chicken movement
and space use is largely dependent upon the local landscape composition
and characteristics of the road itself.
Local electrical distribution lines are usually much shorter in
height than transmission lines but can still contribute to habitat
fragmentation through similar mechanisms as other vertical features
when erected above ground. Distribution lines are similar to
transmission lines with the exception to height of poles and electrical
power carried through the line. In addition to habitat loss and
fragmentation, electrical power lines can directly affect prairie
grouse by posing a collision hazard (Leopold 1933, p. 353; Connelly et
al. 2000, p. 974). There were no datasets available to quantify the
total impact of distribution lines on the landscape for the lesser
prairie-chicken. Although distribution lines are a significant
landscape feature throughout the Great Plains with potential to affect
lesser prairie-chicken habitat, after reviewing all available
information, we were unable to develop a method to quantitatively
incorporate the occurrence of distribution lines into our geospatial
analysis.
As part of our geospatial analysis, we estimated the area impacted
by direct and indirect habitat loss due to roads (Service 2021,
Appendix B, Part 2). These calculations of the current analysis area do
not include historical impacts of loss; thus, it likely underestimates
the historical effect of roads on rangewide habitat loss for the lesser
prairie-chicken. The results indicate that the total areas of grassland
that have been directly and indirectly impacted by roads within the
analysis area for the lesser prairie-chicken are: about 17 percent of
the total area in the Short-Grass/CRP Ecoregion; about 14 percent of
the total area in the Sand Sagebrush Ecoregion; about 20 percent of the
total area in the Mixed-Grass Ecoregion; and about 19 percent of the
total area in the Shinnery Oak Ecoregion. Rangewide, we estimate about
3,996,000 ac (1,617,000 ha) of grassland have been impacted by roads,
representing about 18 percent of the total analysis area (Service 2021,
Appendix E, Figure E.6). We did not have adequate spatial data to
evaluate habitat loss caused solely by power lines, but much of the
existing impacts of power lines occur within the impacts caused by
roads. Power lines that fall outside the existing impacts of roads
would represent additional impacts for the lesser prairie-chicken that
are not quantified in our geospatial analysis.
Development of roads and electrical distribution lines directly
removes habitat that supports lesser prairie-chicken, and the effects
of the development extend past the immediate footprint of the
development, further impacting habitat and altering behavior of lesser
prairie-chicken throughout both the Northern and the Southern DPSs.
These activities have resulted in decreases in population resiliency
and species redundancy.
Other Factors
Livestock Grazing
Grazing has long been an ecological driving force throughout the
ecosystems of the Great Plains (Stebbins 1981, p. 84), and much of the
untilled grasslands within the range of the lesser prairie-chicken is
currently grazed by livestock and other animals. Historically, the
interaction of fire, drought, prairie dogs (Cynomys ludovicianus), and
large ungulate grazers created and maintained distinctive plant
communities in the Western Great Plains, resulting in a mosaic of
vegetation structure and composition that sustained lesser prairie-
chicken and other grassland bird populations (Derner et al. 2009, p.
112). As such, grazing by domestic livestock is not inherently
detrimental to lesser prairie-chicken management and, in many cases, is
needed to maintain appropriate vegetative structure.
However, grazing practices that tend to result in overutilization
of forage and decreasing vegetation heterogeneity can produce habitat
conditions that differ in significant ways from the historical
grassland mosaic; these incompatible practices alter the vegetation
structure and composition and degrade the quality of habitat for the
lesser prairie-chicken. The more heavily altered conditions are the
least valuable for the lesser prairie-chicken (Jackson and DeArment
1963 p. 733; Davis et al. 1979, pp. 56, 116; Taylor and Guthery 1980a,
p. 2; Bidwell and Peoples 1991, pp. 1-2). In some cases, these
alterations can result in areas that do not contain the biological
components necessary to support the lesser prairie-chicken.
Where grazing regimes leave limited residual cover in the spring,
protection of lesser prairie-chicken nests may be inadequate, and
desirable food resources can be scarce (Bent 1932, p. 280; Cannon and
Knopf 1980, pp. 73-74; Crawford 1980, p. 3; Kraft 2016, pp. 19-21).
Because lesser prairie-chicken depend on medium- and tall-grass species
for nesting, concealment, and thermal cover that are also
preferentially grazed by cattle, these plant species needed by lesser
prairie-chicken can easily be reduced or eliminated by cattle grazing,
particularly in regions of low rainfall (Hamerstrom and Hamerstrom
1961, p. 290). In addition, when grasslands are in a deteriorated
condition due to incompatible grazing and overutilization, the soils
have less water-holding capacity (Blanco and Lal 2010, p. 9), and the
availability of succulent vegetation and insects used by lesser
prairie-chicken chicks is reduced. However, grazing can be beneficial
to the lesser prairie-chicken

[[Page 29450]]

when management practices produce or enhance the vegetative
characteristics required by the lesser prairie-chicken.
The interaction of fire and grazing and its effect on vegetation
components and structure is likely important to prairie-chickens
(Starns et al. 2020, entire). On properties managed with patch-burn
grazing regimes, female greater prairie-chickens selected areas with
low cattle stocking rates and patches that were frequently burned,
though they avoided areas that were recently burned (Winder et al.
2017, p. 171). Patch-burn grazing created preferred habitats for female
greater prairie-chickens if the regime included a relatively frequent
fire-return interval, a mosaic of burned and unburned patches, and a
reduced stocking rate in unburned areas avoided by grazers. When
managed compatibly, widespread implementation of patch-burn grazing
could result in significant improvements in habitat quality for
wildlife in the tall-grass prairie ecosystem (Winder et al. 2017, p.
165). In the eastern portion of the lesser prairie-chicken range,
patch-burn grazing resulted in patchy landscapes with variation in
vegetation composition and structure (Lautenbach 2017, p. 20). Female
lesser prairie-chickens' use of the diversity of patches in the
landscape varied throughout their life cycle. They selected patches
with the greatest time-since-fire and subsequently the most visual
obstruction for nesting, and they selected sites with less time-since-
fire and greater bare ground and forbs for summer brooding.
Livestock also inadvertently flush lesser prairie-chicken and
trample lesser prairie-chicken nests (Toole 2005, p. 27; Pitman et al.
2006, pp. 27-29). Brief flushing of adults from nests can expose eggs
and chicks to predation and extreme temperatures. Trampling nests can
cause direct mortality to lesser prairie-chicken eggs or chicks or may
cause adults to permanently abandon their nests, ultimately resulting
in loss of young. Although these effects have been documented, the
significance of direct livestock effects on the lesser prairie-chicken
is largely unknown and is presumed not to be significant at a
population scale.
In summary, domestic livestock grazing (including management
practices commonly used to benefit livestock production) has altered
the composition and structure of grassland habitat, both currently and
historically, used by the lesser prairie-chicken. Much of the remaining
remnants of mixed-grass grasslands, while still important to the lesser
prairie-chicken, exhibit conditions quite different from those prior to
Euro-American settlement. These changes have reduced the suitability of
remnant grassland areas as habitat for lesser prairie-chicken. Grazing
management that has altered the vegetation community to a point where
the composition and structure are no longer suitable for lesser
prairie-chicken can contribute to fragmentation within the landscape,
even though these areas may remain as prairie or grassland. Livestock
grazing, however, is not inherently detrimental to lesser prairie-
chicken provided that grazing management results in a plant community
diversity and structure that is suitable for lesser prairie-chicken.
While domestic livestock grazing is a dominant land use on untilled
range land within the lesser prairie-chicken analysis area, geospatial
data do not exist at a scale and resolution necessary to calculate the
total amount of livestock grazing that is being managed in a way that
results in habitat conditions that are not compatible with the needs of
the lesser prairie-chicken. Therefore, we did not attempt to spatially
quantify the scope of grazing effects across the lesser prairie-chicken
range.
Shrub Control and Eradication
Shrub control and eradication are additional forms of habitat
alteration that can influence the availability and suitability of
habitat for lesser prairie-chicken (Jackson and DeArment 1963, pp. 736-
737). Most shrub control and eradication efforts in lesser prairie-
chicken habitat are primarily focused on sand shinnery oak for the
purpose of increasing forage for livestock grazing. Sand shinnery oak
is toxic if eaten by cattle when it first produces leaves in the spring
and competes with more palatable grasses and forbs for water and
nutrients (Peterson and Boyd 1998, p. 8), which is why it is a common
target for control and eradication efforts by rangeland managers. Prior
to the late 1990s, approximately 100,000 ac (40,000 ha) of sand
shinnery oak in New Mexico and approximately 1,000,000 ac (405,000 ha)
of sand shinnery oak in Texas were lost due to the application of
tebuthiuron and other herbicides for agriculture and range improvement
(Peterson and Boyd 1998, p. 2).
Shrub cover is an important component of lesser prairie-chicken
habitat in certain portions of the range, and sand shinnery oak is a
key shrub in the Shinnery Oak and portions of the Mixed-Grass
Ecoregions. The importance of sand shinnery oak as a component of
lesser prairie-chicken habitat in the Shinnery Oak Ecoregion has been
demonstrated by several studies (Fuhlendorf et al. 2002, pp. 624-626;
Bell 2005, pp. 15, 19-25). In West Texas and New Mexico, lesser
prairie-chicken avoid nesting where sand shinnery oak has been
controlled with tebuthiuron, indicating their preference for habitat
with a sand shinnery oak component (Grisham et al. 2014, p. 18; Haukos
and Smith 1989, p. 625; Johnson et al. 2004, pp. 338-342; Patten and
Kelly 2010, p. 2151). Where sand shinnery oak occurs, lesser prairie-
chicken use it both for food and cover. Sand shinnery oak may be
particularly important in drier portions of the range that experience
more severe and frequent droughts and extreme heat events, as sand
shinnery oak is more resistant to drought and heat conditions than are
most grass species. And because sand shinnery oak is toxic to cattle
and thus not targeted by grazing, it can provide available cover for
lesser prairie-chicken nesting and brood rearing during these extreme
weather events. Loss of this component of the vegetative community
likely contributed to observed population declines in lesser prairie-
chicken in these areas.
While relatively wide-scale shrub eradication has occurred in the
past, geospatial data do not exist to evaluate the extent to which
shrub eradication has contributed to the habitat loss and fragmentation
for the lesser prairie-chicken and, therefore, was not included in our
quantitative analysis. While current efforts of shrub eradication are
not likely occurring at rates equivalent to that witnessed in the past,
any additional efforts to eradicate shrubs that are essential to lesser
prairie-chicken habitat will result in additional habitat degradation
and thus reduce redundancy and resiliency.
Influence of Anthropogenic Noise
Anthropogenic noise can be associated with almost any form of human
activity, and lesser prairie-chicken may exhibit behavioral and
physiological responses to the presence of noise. In prairie-chickens,
the ``boom'' call vocalization transmits information about sex,
territorial status, mating condition, location, and individual identity
of the signaler and thus is important to courtship activity and long-
range advertisement of the display ground (Sparling 1981, p. 484). The
timing of displays and frequency of vocalizations are critical
reproductive behaviors in prairie grouse and appear to have developed
in response to unobstructed conditions prevalent in prairie habitat and
indicate that effective communication, particularly during the lekking
season, operates within a fairly narrow set of acoustic conditions.
Prairie grouse usually

[[Page 29451]]

initiate displays on the lekking grounds around sunrise, and
occasionally near sunset, corresponding with times of decreased wind
turbulence and thermal variation (Sparling 1983, p. 41). Considering
the narrow set of acoustic conditions in which communication appears
most effective for breeding lesser prairie-chicken and the importance
of communication to successful reproduction, human activities that
result in noises that disrupt or alter these conditions could result in
lek abandonment (Crawford and Bolen 1976b, p. 239). Anthropogenic
features and related activities that occur on the landscape can create
noise that exceeds the natural background or ambient level. When the
behavioral response to noise is avoidance, as it often is for lesser
prairie-chicken, noise can be a source of habitat loss or degradation
leading to increased habitat fragmentation.
Anthropogenic noise may be a possible factor in the population
declines of other species of lekking grouse in North America,
particularly for populations that are exposed to human developments
(Blickley et al. 2012a, p. 470; Lipp and Gregory 2018, pp. 369-370).
Male greater prairie-chicken adjust aspects of their vocalizations in
response to wind turbine noise, and wind turbine noise may have the
potential to mask the greater prairie-chicken chorus at 296 hertz (Hz)
under certain scenarios, but the extent and degree of masking is
uncertain (Whalen 2015, entire). Noise produced by typical oil and gas
infrastructure can mask grouse vocalizations, compromise the ability of
female sage-grouse to find active leks when such noise is present, and
affect nest site selection (Blickley and Patricelli 2012, p. 32; Lipp
2016, p. 40). Chronic noise associated with human activity leads to
reduced male and female attendance at noisy leks. Breeding,
reproductive success, and ultimately recruitment in areas with human
developments could be impaired by such developments, impacting survival
(Blickley et al. 2012b, entire). Because opportunities for effective
communication on the display ground occur under fairly narrow
conditions, disturbance during this period may have negative
consequences for reproductive success. Other communications used by
grouse off the lek, such as parent-offspring communication, may
continue to be susceptible to masking by noise from human
infrastructure (Blickley and Patricelli 2012, p. 33).
No data are available to quantify the areas of lesser prairie-
chicken habitat rangewide that have been affected by noise, but noise
is a threat that is almost entirely associated with anthropogenic
features such as roads or energy development. Therefore, through our
accounting for anthropogenic features we may have inherently accounted
for all or some of the response of the lesser prairie-chicken to noise
produced by those features.
Overall, persistent anthropogenic noise could cause lek attendance
to decline, disrupt courtship and breeding activity, and reduce
reproductive success. Noise can also cause abandonment of otherwise
usable habitat and, as a result, contribute to habitat loss and
degradation.
Fire
Fire, or its absence, is understood to be a major ecological driver
of grasslands in the Southern Great Plains (Anderson 2006, entire;
Koerner and Collins 2014, entire; Wright and Bailey 1982, pp. 80-137).
Fire is an ecological process important to maintaining grasslands by
itself and in coupled interaction with grazing and climate. The
interaction of these ecological processes results in increasing
grassland heterogeneity through the creation of temporal and spatial
diversity in plant community composition and structure and associated
response of wildlife (Fuhlendorf and Engle 2001, entire; Fuhlendorf and
Engle 2004, entire; Fuhlendorf et al. 2017a, pp. 169-196).
Following settlement of the Great Plains, fire management generally
emphasized prevention and suppression, often coupled with grazing
pressures that significantly reduced and removed fine fuels (Sayre
2017, pp. 61-70). This approach, occurring in concert with settlement
and ownership patterns that occurred in most of the Southern Great
Plains, meant that the scale of management was relegated to smaller
parcels than historically were affected. This increase in smaller
parcels with both intensive grazing and fire suppression resulted in
the transformation of landscapes from dynamic heterogeneous to largely
static and homogenous plant communities. This simplification of
vegetative pattern due to decoupling fire and grazing (Starns et al.
2019, pp. 1-3) changed the number and size of wildfires and ultimately
led to declines in biodiversity in the affected systems (Fuhlendorf and
Engle 2001, entire).
Changes in patterns of wildfire in the Great Plains have been noted
in recent years (Donovan et al. 2017, entire). While these landscapes
have a long history of wildfire, large wildfires (greater than 1,000 ac
(400 ha)) typically did not occur in recent past decades, and include
an increase in the Southern Great Plains of megafires (greater than
100,000 ac (400 km\2\)) since the mid-1990s (Lindley et al. 2019, p.
164). Changes have occurred throughout all or portions of the Great
Plains in number of large wildfires and season of fire occurrence, as
well as increased area burned by wildfire or increasing probability of
large wildfires (Donovan et al. 2017, p. 5990). Furthermore, Great
Plains land cover dominated by woody or woody/grassland combined
vegetation is disproportionately more likely to experience large
wildfires, with the greatest increase in both number of fires and of
area burned (Donovan et al. 2020a, p. 11). Fire behavior has also been
affected such that these increasingly large wildfires are burning under
weather conditions (Lindley et al. 2019, entire) that result in greater
burned extent and intensity. These shifts in fire parameters and their
outcomes have potential consequences for lesser prairie-chicken,
including: (1) Larger areas of complete loss of nesting habitat as
compared to formerly patchy mosaicked burns; and (2) large-scale
reduction in the spatial and temporal variation in vegetation structure
and composition affecting nesting and brood-rearing habitat,
thermoregulatory cover, and predator escape cover.
Effects from fire are expected to be relatively short term (Donovan
et al. 2020b, entire, Starns et al. 2020, entire) with plant community
recovery time largely predictable and influenced by pre-fire condition,
post-fire weather, and types of management. Some effects from fire,
however, such as the response to changing plant communities in the
range of the lesser prairie-chicken, will vary based on location within
the range and available precipitation. In the eastern extent of the
distribution of sand shinnery oak that occurs in the Mixed-Grass
Ecoregion, fire has potential negative effects on some aspects of the
lesser prairie-chicken habitat for 2 years after the area burns, but
these effects could be longer in duration dependent upon precipitation
patterns (Boyd and Bidwell 2001, pp. 945-946). Effects from fire on
lesser prairie-chicken varied based on fire break preparation, season
of burn, and type of habitat; positive effects included improved brood
habitat through increased forb and grasshopper abundance, but these can
be countered by short-term (2-year) negative effects to quality and
availability of nesting habitat and a reduction in food sources (Boyd
and Bidwell 2001, pp. 945-946). Birds moved into recently burned
landscapes of western Oklahoma for lek courtship

[[Page 29452]]

displays because of the reduction in structure from formerly dense
vegetation (Cannon and Knopf 1979, entire).
More recently, research evaluating indirect effects concluded that
prescribed fire and managed grazing following the patch-burn or pyric
herbivory (grazing practices shaped fire) approach will benefit lesser
prairie-chicken through increases in forbs; invertebrates; and the
quality, amount, and juxtaposition of brood habitat to available
nesting habitat (Elmore et al. 2017, entire). The importance of
temporal and spatial heterogeneity derived from pyric herbivory is
apparent in the female lesser prairie-chicken use of all patch types in
the patch-burn grazing mosaic, including greater than 2 years post-fire
for nesting, 2-year post fire during spring lekking, 1- and 2-year
post-fire during summer brooding, and 1-year post-fire during
nonbreeding season (Lautenbach 2017, pp. 20-22). While the use of
prescribed fire as a tool for managing grasslands throughout the lesser
prairie-chicken range is encouraged, current use is at a temporal
frequency and spatial extent insufficient to support large amount of
lesser prairie-chicken habitat. These fire management efforts are
limited to a small number of fire-minded landowners, resulting in
effects to a small percentage of the lesser prairie-chicken range.
While lesser prairie-chicken evolved in a fire-adapted landscape,
little research (Thacker and Twidwell 2014, entire) has been conducted
on response of lesser prairie-chicken to altered fire regimes. Research
to date has focused on site-specific responses and consequences. Human
suppression of wildfire and the limited extent of fire use (prescribed
fire) for management over the past century has altered the frequency,
scale, and intensity of fire occurrence in lesser prairie-chicken
habitat. These changes in fire parameters have happened simultaneously
with habitat loss and fragmentation, resulting in patchy distribution
of lesser prairie-chicken throughout their range. An increase in size,
intensity, or severity of wildfires as compared to historical
occurrences results in increased vulnerability of isolated, smaller
lesser prairie-chicken populations. Both woody plant encroachment and
drought are additive factors that increase risk of negative
consequences of wildfire ignition, as well as extended post-fire lesser
prairie-chicken habitat effects. The extent of these negative impacts
can be significantly altered by precipitation patterns following the
occurrence of the fire; dry periods will inhibit or extend plant
community response.
Historically, fire served an important role in maintenance and
quality of habitat for the lesser prairie-chicken. Currently, due to a
significant shift in fire regimes in the lesser prairie-chicken range,
fire use for management of grasslands plays a locally important but
overall limited role in most lesser prairie-chicken habitat. This
current lack of prescribed fire use in the range of the lesser prairie-
chicken is contributing to woody plant encroachment and degradation of
grassland quality due to its decoupling from the grazing and fire
interaction that is the foundation for plant community diversity in
structure and composition, which in turn supports the diverse habitat
needs of lesser prairie-chicken. These cascading effects contribute to
greater wildfire risk, and concerns exist regarding the changing
patterns of wildfires (scale, intensity, and frequency) and their
consequences for remaining lesser prairie-chicken populations and
habitat that are increasingly fragmented. Concurrently, wildfire has
increased as a threat rangewide due to compounding influences of
increased size and severity of wildfires and the potential consequences
to remaining isolated and fragmented lesser prairie-chicken
populations.
Extreme Weather Events
Weather-related events such as drought, snow, and hail storms can
influence habitat quality or result in direct mortality of lesser
prairie-chickens. Although hail storms typically only have a localized
effect, the effects of snow storms and drought can often be more
widespread and can affect considerable portions of the lesser prairie-
chicken range. Drought is considered a universal ecological driver
across the Great Plains (Knopf 1996, p. 147). Annual precipitation
within the Great Plains is highly variable (Wiens 1974, p. 391), with
prolonged drought capable of causing local extinctions of annual forbs
and grasses within stands of perennial species; recolonization is often
slow (Tilman and El Haddi 1992, p. 263). Grassland bird species in
particular are impacted by climate extremes such as extended drought,
which acts as a bottleneck that allows only a limited number of
individuals to survive through the relatively harsh conditions (Wiens
1974, pp. 388, 397; Zimmerman 1992, p. 92). Drought also interacts with
many of the other threats impacting the lesser prairie-chicken and its
habitat, such as amplifying the effects of incompatible grazing and
predation.
Although the lesser prairie-chicken has adapted to drought as a
component of its environment, drought and the accompanying harsh,
fluctuating conditions (high temperatures and low food and cover
availability) have influenced lesser prairie-chicken populations.
Widespread periods of drought commonly result in ``bust years'' of
recruitment. Following extreme droughts of the 1930s, 1950s, 1970s, and
1990s, lesser prairie-chicken population levels declined and a decrease
in their overall range was observed (Lee 1950, p. 475; Ligon 1953, p.
1; Schwilling 1955, pp. 5-6; Hamerstrom and Hamerstrom 1961, p. 289;
Copelin 1963, p. 49; Crawford 1980, pp. 2-5; Massey 2001, pp. 5, 12;
Hagen and Giesen 2005, unpaginated). Additionally, lesser prairie-
chicken populations reached near record lows during and after the more
recent drought of 2011 to 2013 (McDonald et al. 2017, p. 12; Fritts et
al. 2018, entire).
Drought impacts prairie grouse, such as lesser prairie-chicken,
through several mechanisms. Drought affects seasonal growth of
vegetation necessary to provide suitable nesting and roosting cover,
food, and opportunity for escape from predators (Copelin 1963, pp. 37,
42; Merchant 1982, pp. 19, 25, 51; Applegate and Riley 1998, p. 15;
Peterson and Silvy 1994, p. 228; Morrow et al. 1996, pp. 596-597; Ross
et al. 2016a, entire). Lesser prairie-chicken home ranges will
temporarily expand during drought years (Copelin 1963, p. 37; Merchant
1982, p. 39) to compensate for scarcity in available resources. During
these periods, the adult birds expend more energy searching for food
and tend to move into areas with limited cover in order to forage,
leaving them more vulnerable to predation and heat stress (Merchant
1982, pp. 34-35; Flanders-Wanner et al. 2004, p. 31). Chick survival
and recruitment may also be depressed by drought (Merchant 1982, pp.
43-48; Morrow et al. 1996, p. 597; Giesen 1998, p. 11; Massey 2001, p.
12), which likely affects population trends more than annual changes in
adult survival (Hagen 2003, pp. 176-177). Drought-induced mechanisms
affecting recruitment include decreased physiological condition of
breeding females (Merchant 1982, p. 45); heat stress and water loss of
chicks (Merchant 1982, p. 46); and effects to hatch success and
juvenile survival due to changes in microclimate, temperature, and
humidity (Patten et al. 2005, pp. 1274-1275; Bell 2005, pp. 20-21; Boal
et al. 2010, p. 11). Precipitation, or lack thereof, appears to affect
lesser

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prairie-chicken adult population trends with a potential lag effect
(Giesen 2000, p. 145; Ross et al. 2016a, pp. 6-8). That is, rain levels
in one year promote more vegetative cover for eggs and chicks in the
following year, which influences survival and reproduction.
Although lesser prairie-chicken have persisted through droughts in
the past, the effects of such droughts are exacerbated by human land
use practices such as incompatible grazing and land cultivation
(Merchant 1982, p. 51; Hamerstrom and Hamerstrom 1961, pp. 288-289;
Davis et al. 1979, p. 122; Taylor and Guthery 1980a, p. 2; Ross et al.
2016b, pp. 183-186) as well as the other threats that have affected the
current condition and have altered and fragmented the landscape and
decreased population abundances (Fuhlendorf et al. 2002, p. 617;
Rodgers 2016, pp. 15-19). In past decades, fragmentation of lesser
prairie-chicken habitat was less extensive than it is today,
connectivity between occupied areas was more prevalent, and populations
were larger, allowing populations to recover more quickly. In other
words, lesser prairie-chicken populations were more resilient to the
effects of stochastic events such as drought. As lesser prairie-chicken
population abundances decline and usable habitat declines and becomes
more fragmented, their ability to rebound from prolonged drought is
diminished.
Hail storms can cause mortality of prairie grouse, particularly
during the spring nesting season. An excerpt from the May 1879 Stockton
News that describes a large hailstorm near Kirwin, Kansas, as
responsible for killing prairie-chickens (likely greater prairie-
chicken) and other birds by the hundreds (Fleharty 1995, p. 241).
Although such phenomena are likely rare, the effects can be
significant, particularly if they occur during the nesting period and
result in significant loss of eggs or chicks. Severe winter storms can
also result in localized impacts to lesser prairie-chicken populations.
For example, a severe winter storm in 2006 was reported to reduce
lesser prairie-chicken numbers in Colorado by 75 percent from 2006 to
2007, from 296 birds observed to only 74. Active leks also declined
from 34 leks in 2006 to 18 leks in 2007 (Verquer 2007, p. 2). While
populations commonly rebound to some degree following severe weather
events such as drought and winter storms, a population with decreased
resiliency becomes susceptible to extirpation from stochastic events.
We are not able to quantify the impact that severe weather has had
on the lesser prairie-chicken populations, but, as discussed above,
these events have shaped recent history and influenced the current
condition for the lesser prairie-chicken.
Regulatory Mechanisms
In Appendix D of the SSA report (Service 2021), we review in more
detail the existing regulatory mechanisms (such as local, State, and
Federal land use regulations or laws) that may be significant to lesser
prairie-chicken conservation. Here, we present a summary of some of
those regulatory mechanisms. All existing regulatory mechanisms were
fully considered in our conclusion about the status of the two DPSs.
All five States in the estimated occupied range have incorporated
the lesser prairie-chicken as a species of conservation concern and
management priority in their respective State Wildlife Action Plans.
While identification of the lesser prairie-chicken as a species of
conservation concern helps heighten public awareness, this designation
provides no protection from direct take or habitat destruction or
alteration. The lesser prairie-chicken is listed as threatened in
Colorado; this listing protects the lesser prairie-chicken from direct
purposeful mortality by humans but does not provide protections for
destruction or alteration of habitat.
Primary land ownership (approximately 5 percent of total range) at
the Federal level is on USFS and BLM lands. The lesser prairie-chicken
is present on the Cimarron National Grassland in Kansas and the
Comanche National Grassland in Colorado; a total of approximately 3
percent of the total acres estimated in the current condition is on
USFS land. The 2014 Lesser Prairie-Chicken Management Plan for these
grasslands provides a framework to manage lesser prairie-chicken
habitat. The plan provides separate population and habitat recovery
goals for each grassland, as well as vegetation surveys to inform
ongoing and future monitoring efforts of suitable habitat and lek
activities. Because National Grasslands are managed for multiple uses,
the plan includes guidelines for prescribed fire and grazing.
In New Mexico, roughly 41 percent of the known historical and most
of the estimated occupied lesser prairie-chicken range occurs on BLM
land, for a total of 3 percent of the total acres estimated in the
current condition. The BLM established the 57,522-ac (23,278-ha) Lesser
Prairie-Chicken Habitat Preservation Area of Critical Environmental
Concern (ACEC) upon completion of the Resource Management Plan
Amendment (RMPA) in 2008. The management goal for the ACEC is to
protect the biological qualities of the area, with emphasis on the
preservation of the shinnery oak-dune community to enhance the
biodiversity of the ecosystem, particularly habitats for the lesser
prairie-chicken and the dunes sagebrush lizard. Upon designation, the
ACEC was closed to future oil and gas leasing, and existing leases
would be developed in accordance with prescriptions applicable to the
Core Management Area as described below (BLM 2008, p. 30). Additional
management prescriptions for the ACEC include designation as a right-
of-way exclusion area, vegetation management to meet the stated
management goal of the area, and limiting the area to existing roads
and trails for off-highway vehicle use (BLM 2008, p. 31). All acres of
the ACEC have been closed to grazing through relinquishment of the
permits except for one 3,442-ac (1,393-ha) allotment.
The BLM's approved RMPA (BLM 2008, pp. 5-31) provides some limited
protections for the lesser prairie-chicken in New Mexico by reducing
the number of drilling locations, decreasing the size of well pads,
reducing the number and length of roads, reducing the number of
powerlines and pipelines, and implementing best management practices
for development and reclamation. The effect of these best management
practices on the status of the lesser prairie-chicken is unknown,
particularly considering about 82,000 ac (33,184 ha) have already been
leased in those areas (BLM 2008, p. 8). Although the BLM RMPA is an
important tool for identifying conservation actions that would benefit
lesser prairie-chicken, this program is not adequate to eliminate
threats to the species such that is does not warrant listing under the
Act.
No new mineral leases will be issued on approximately 32 percent of
Federal mineral acreage within the RMPA planning area (BLM 2008, p. 8),
although some exceptions are allowed on a case-by-case basis (BLM 2008,
pp. 9-11). Within the Core Management Area and Primary Population Area,
new leases will be restricted in occupied and suitable habitat;
however, if there is an overall increase in reclaimed to disturbed
acres over a 5-year period, new leases in these areas will be allowed
(BLM 2008, p. 11). In the southernmost habitat management units, where
lesser prairie-chickens are now far less common than in previous
decades (Hunt and Best 2004), new

[[Page 29454]]

leases will not be allowed within 2.4 km (1.5 mi) of a lek (BLM 2008,
p. 11).
We conclude that existing regulatory mechanisms have minimal
influence on the rangewide trends of lesser prairie-chicken habitat
loss and fragmentation because 97 percent of the lesser prairie-chicken
analysis area occurs on private lands, and the activities affecting
lesser prairie-chicken habitat are largely unregulated land use
practices and land development.
Conservation Efforts
The SSA report also includes detailed information on current
conservation measures (Service 2021, pp. 49-61). Some programs are
implemented across the species' range, and others are implemented at
the State or local level. Because the vast majority of lesser prairie-
chicken and their habitat occurs on private lands, most of these
programs are targeted toward voluntary, incentive-based actions in
cooperation with private landowners.
At the rangewide scale, plans include the Lesser Prairie-Chicken
Rangewide Conservation Plan, the Lesser Prairie-Chicken Initiative, and
the Conservation Reserve Program. Below is a summary of the primary
rangewide conservation efforts. For detailed descriptions of each
program, please see the SSA report. All existing ongoing conservation
efforts were fully considered in our finding on the status of the two
DPSs.
In 2013, the State fish and wildlife agencies within the range of
the lesser prairie-chicken and the Western Association of Fish and
Wildlife Agencies (WAFWA) finalized the Lesser Prairie-Chicken Range-
wide Conservation Plan (RWP) in response to concerns about threats to
lesser prairie-chicken habitat and resulting effects to lesser prairie-
chicken populations (Van Pelt et al. 2013, entire). The RWP established
biological goals and objectives as well as a conservation targeting
strategy that aims to unify conservation efforts towards common goals.
Additionally, the RWP establishes a mitigation framework administered
by WAFWA that allows industry participants the opportunity to mitigate
unavoidable impacts of a particular activity on the lesser prairie-
chicken. After approval of the RWP, WAFWA developed a companion oil and
gas candidate conservation agreement with assurances (CCAA), which
adopted the mitigation framework contained within the RWP that was
approved in 2014.
As of August 1, 2020, WAFWA had used incoming funds from industry
participants to place 22 sites totaling 128,230 unimpacted ac (51,893
ha) under conservation contracts to provide offset for industry impacts
that have occurred through the RWP and CCAA (Moore 2020, p. 9). These
areas are enrolled under RWP conservation contracts that will provide
mitigation for 1,538 projects, which impacted 48,743 ac (19,726 ha)
(WAFWA 2020, table 32, unpaginated). When enrolling a property,
industry participants agree to minimize impacts from projects to lesser
prairie-chicken habitat and mitigate for all remaining impacts on the
enrolled property. At the end of 2019 in the CCAA, there were 111
active contracts (Certificates of Inclusion) with 6,228,136 ac
(2,520,437 ha) enrolled (Moore 2020, p. 4), and in the WAFWA
Conservation Agreement there were 52 active WAFWA Conservation
Agreement contracts (Certificates of Participation) with 599,626 ac
(242,660 ha) enrolled (WAFWA 2020, Table 5 unpaginated). A recent audit
of the mitigation program associated with the RWP and CCAA identified
several key issues to be resolved within the program to ensure
financial stability and effective conservation outcomes (Moore 2020,
Appendix E). WAFWA has hired a consultant who is currently working with
stakeholders, including the Service, to consider available options to
address the identified issues to ensure long-term durability of the
strategy.
In 2010, the U.S. Department of Agriculture's (USDA) Natural
Resources Conservation Service (NRCS) began implementation of the
Lesser Prairie-Chicken Initiative (LPCI). The LPCI provides
conservation assistance, both technical and financial, to landowners
throughout the LPCI's administrative boundary (NRCS 2017, p. 1). The
LPCI focuses on maintenance and enhancement of lesser prairie-chicken
habitat while benefiting agricultural producers by maintaining the
farming and ranching operations throughout the region. In 2019, after
annual declines in landowner interest in LPCI, the NRCS made changes in
how LPCI will be implemented moving forward and initiated conferencing
under section 7 of the ESA with the Service. Prior to 2019,
participating landowners had to address all threats to the lesser
prairie-chicken present on their property. In the future, each
conservation plan developed under LPCI will only need to include one or
more of the core management practices that include prescribed grazing,
prescribed burning, brush management, and upland wildlife habitat
management. Additional management practices may be incorporated into
each conservation plan, as needed, to facilitate meeting the desired
objectives. These practices are applied or maintained annually for the
life of the practice, typically 1 to 15 years, to treat or manage
habitat for lesser prairie-chicken. From 2010 through 2019, NRCS worked
with 883 private agricultural producers to implement conservation
practices on 1.6 million ac (647,497 ha) of working lands within the
historical range of the lesser prairie-chicken (NRCS 2020, p. 2).
During that time, through LPCI, NRCS implemented prescribed grazing
plans on 680,800 ac (275,500 ha) across the range (Griffiths 2020,
pers. comm.). Through LPCI, NRCS has also removed over 41,000 ac
(16,600 ha) of eastern red cedar in the Mixed-Grass Ecoregion and
chemically treated approximately 106,000 ac (43,000 ha) of mesquite in
the Shinnery Oak Ecoregion. Lastly, NRCS has conducted prescribed burns
on approximately 15,000 ac (6,000 ha) during this time.
The Conservation Reserve Program (CRP) is administered by the
USDA's Farm Service Agency and provides short-term protection and
conservation benefits on millions of acres within the range of the
lesser prairie-chicken. The CRP is a voluntary program that allows
eligible landowners to receive annual rental payments and cost-share
assistance in exchange for removing cropland and certain marginal
pastureland from agricultural production. CRP contract terms are for 10
to 15 years. The total amount of land that can be enrolled in the CRP
is capped nationally by the Food Security Act of 1985, as amended (the
2018 Farm Bill) at 27 million ac (10.93 million ha). All five States
within the range of the lesser prairie-chicken have lands enrolled in
the CRP. The 2018 Farm Bill maintains the acreage limitation that not
more than 25 percent of the cropland in any county can be enrolled in
CRP, with specific conditions under which a waiver to this restriction
can be provided for lands enrolled under the Conservation Reserve
Enhancement Program (84 FR 66813, December 6, 2019). Over time, CRP
enrollment fluctuates both nationally and locally. Within the counties
that intersect the Estimated Occupied Range plus a 10-mile buffer,
acres enrolled in CRP have declined annually since 2007 (with the
exception of one minor increase from 2010 to 2011) from nearly 6
million ac (2.4 million ha) enrolled to current enrollment levels of
approximately 4.25 million ac (1.7 million ha) (FSA 2020a, unpublished
data). More specific to our analysis area, current acreage of CRP
enrollment is approximately 1,822,000 ac (737,000 ha) within our
analysis area. Of those currently enrolled acres there

[[Page 29455]]

are approximately 120,000 ac (49,000 ha) of introduced grasses and
legumes dispersed primarily within the Mixed-Grass and Shinnery Oak
Ecoregions (FSA 2020b, unpublished data).
At the State level, programs provide direct technical and financial
cost-share assistance to private landowners interested in voluntarily
implementing conservation management practices to benefit species of
greatest conservation need--including the lesser prairie-chicken.
Additionally, a variety of State-level conservation efforts acquire and
manage lands or incentivize management by private landowners for the
benefit of the lesser prairie-chicken. Below is a summary for each
State within the range of the lesser prairie-chicken. For a complete
description of each, see the SSA report. All conservation measures
discussed in the SSA report were fully considered in this proposed
rule.
Within the State of Kansas, conservation efforts are administered
by the Kansas Department of Wildlife, Parks and Tourism (KDWPT), The
Nature Conservancy, and the Service's Partners for Fish and Wildlife
Program (PFW). KDWPT has targeted lesser prairie-chicken habitat
improvements on private lands by leveraging landowner cost-share
contributions, industry and nongovernmental organizations' cash
contributions, and agency funds toward several federally funded grant
programs. The KDWPT has implemented conservation measures over 22,000
ac (8,900 ha) through the Landowner Incentive Program, over 18,000 ac
(7,285 ha) through the State Wildlife Grant Private Landowner Program,
30,000 ac (12,140 ha) through the Wildlife Habitat Incentives Program,
and 12,000 ac (4,855 ha) through the Habitat First Program within the
range of the lesser prairie-chicken. Additionally, KDWPT was provided
an opportunity through contributions from the Comanche Pool Prairie
Resource Foundation to leverage additional Wildlife and Sport Fish
Restoration funds in 2016 to direct implementation of 19,655 ac (7,954
ha). The Nature Conservancy in Kansas manages the 18,060-ac (7,309-ha)
Smoky Valley Ranch. The Nature Conservancy also serves as the easement
holder for nearly 34,000 ac (13,760 ha) of properties that are enrolled
under the RWP. The Nature Conservancy is also working to use funds from
an NRCS Regional Conservation Partnership Program that have resulted in
nearly 50,000 ac (20,235 ha) on three ranches either with secured or
in-process conservation easements. The Service's PFW program has
executed 95 private lands agreements with direct and indirect
improvements on about 173,000 ac (70,011 ha) of private lands
benefitting conservation of the lesser prairie-chicken in Kansas.
In 2009, Colorado Parks and Wildlife (CPW) initiated its Lesser
Prairie-Chicken Habitat Improvement Program that provides cost-sharing
to private landowners who participate in practices such as deferred
grazing around active leks, enhancement of fields enrolled in CRP and
cropland-to-grassland habitat conversion. Since program inception, CPW
has completed 37,051 ac (14,994 ha) of habitat treatments. The Nature
Conservancy holds permanent conservation easements on multiple ranches
that make up the Big Sandy complex. Totaling approximately 48,940 ac
(19,805 ha), this complex is managed with lesser prairie-chicken as a
conservation objective and perpetually protects intact sand sagebrush
and short-grass prairie communities. The USFS currently manages the
Comanche Lesser Prairie-Chicken Habitat Zoological Area, as part of the
Comanche and Cimarron National Grasslands, which encompass an area of
10,177 ac (4,118 ha) in Colorado that is managed to benefit the lesser
prairie-chicken (USFS 2014, p. 9). In 2016, CPW and KDWPT partnered
with Kansas State University and USFS to initiate a 3-year
translocation project to restore lesser prairie-chicken to the Comanche
National Grasslands (Colorado) and Cimarron National Grasslands
(Kansas). Beginning in the fall of 2016 and concluding with the 2019
spring lekking season, the partnership trapped and translocated 411
lesser prairie-chickens from the Short-Grass/CRP Ecoregion in Kansas to
the Sand Sagebrush Ecoregion. During April and May 2020 lek counts,
Colorado and Kansas biologists and technicians found 115 male birds on
20 active leks in the landscape around the Comanche and Cimarron
National Grasslands (Rossi 2020, pers. comm.).
In 2013, the Oklahoma Department of Wildlife Conservation (ODWC)
was issued a 25-year enhancement of survival permit pursuant to section
10(a)(1)(A) of the ESA that included an umbrella CCAA between the
Service and ODWC for the lesser prairie-chicken in 14 Oklahoma counties
(78 FR 14111, March 4, 2013). As of 2019, there were 84 participants
with a total of 399,225 ac (161,561 ha) enrolled in the ODWC CCAA, with
357,654 ac (144,737) enrolled as conservation acres (ODWC 2020). The
ODWC owns six wildlife management areas totaling approximately 75,000
ac (30,351 ha) in the range of the lesser prairie-chicken, though only
a portion of each wildlife management area can be considered as
conservation acres for lesser prairie-chicken. The Service's PFW
program has funded a shared position with ODWC for 6 years to conduct
CCAA monitoring and, in addition, has provided funding for on-the-
ground work in the lesser prairie-chicken range. Since 2017, the
Oklahoma PFW program has implemented 51 private lands agreements on
about 10,603 ac (4,291 ha) for the benefit of the lesser prairie-
chicken in Oklahoma. The Nature Conservancy of Oklahoma manages the
4,050-ac (1,640-ha) Four Canyon Preserve in Ellis County for ecological
health to benefit numerous short-grass prairie species, including the
lesser prairie-chicken. In 2017, The Nature Conservancy acquired a
conservation easement on 1,784 ac (722 ha) in Woods County. The
Conservancy is seeking to permanently protect additional acreage in the
region through the acquisition of conservation easements.
Texas Parks and Wildlife Department (TPWD) worked with the Service
and landowners to develop the first state-wide umbrella CCAA for the
lesser prairie-chicken in Texas, which was finalized in 2006. The Texas
CCAA covers 50 counties, largely encompassing the Texas Panhandle and
South Plains regions. Total landowner participation by the close of
January 2020 was 91 properties totaling approximately 657,038 ac
(265,894 ha) enrolled in 15 counties (TPWD 2020, entire). The Service's
PFW program and the TPWD have actively collaborated on range management
programs designed to provide cost-sharing for implementation of habitat
improvements for lesser prairie-chicken. The Service provided funding
to TPWD to support a Landscape Conservation Coordinator position for
the Panhandle and Southern High Plains region, as well as funding to
support Landowner Incentive Program projects targeting lesser prairie-
chicken habitat improvements (brush control and grazing management) in
this region. More than $200,000 of Service funds were committed in
2010, and an additional $100,000 was committed in 2011.
Since 2008, Texas has addressed lesser prairie-chicken conservation
on 14,068 ac (5,693 ha) under the Landowner Incentive Program. Typical
conservation measures include native plant restoration, control of
exotic or invasive vegetation, prescribed burning, selective brush
management, and prescribed grazing. The PFW program in Texas has
executed 66 private lands agreements on about 131,190 ac (53,091

[[Page 29456]]

ha) of privately owned lands for the benefit of the lesser prairie-
chicken in Texas. The Nature Conservancy of Texas acquired
approximately 10,635 ac (4,303 ha) in Cochran, Terry, and Yoakum
Counties. In 2014, The Nature Conservancy donated this land to TPWD.
The TPWD acquired an additional 3,402 ac (1,377 ha) contiguous to the
Yoakum Dunes Preserve creating the 14,037-ac (5,681-ha) Yoakum Dunes
Wildlife Management Area. In 2015, through the RWP process, WAFWA
acquired an additional 1,604 ac (649 ha) in Cochran County, nearly 3 mi
(5 km) west of the Yoakum Dunes Wildlife Management Area. The land was
deeded to TPWD soon after acquisition. In 2016, an additional 320 ac
(129 ha) was purchased by TPWD bordering the WAFWA acquired tract
creating an additional 1,924-ac (779-ha) property that is being managed
as part of the Yoakum Dunes Wildlife Management Area, now at 15,961 ac
(6,459 ha).
The BLM's Special Status Species RMPA, which was approved in April
2008, addressed the concerns and future management of lesser prairie-
chicken and dunes sagebrush lizard habitats on BLM lands and
established the Lesser Prairie-Chicken Habitat Preservation Area of
Critical Environmental Concern (BLM 2008, entire). Since the RMPA was
approved in 2008, BLM has closed approximately 300,000 ac (121,000 ha)
to future oil and gas leasing and closed approximately 850,000 ac
(344,000 ha) to wind and solar development (BLM 2008, p. 3). From 2008
to 2020, they have reclaimed 3,500 ac (1,416 ha) of abandoned well pads
and associated roads and required burial of power lines within 2 mi
(3.2 km) of lesser prairie-chicken leks. Additionally, BLM has
implemented control efforts for mesquite on 832,104 ac (336,740 ha) and
has plans to do so on an additional 30,000 ac (12,141 ha) annually. In
2010, BLM acquired 7,440 ac (3,010 ha) of land east of Roswell, New
Mexico, to complete the 54,000-ac (21,853-ha) ACEC for lesser prairie-
chicken, which is managed to protect key habitat.
Following approval of the RMPA, a candidate conservation agreement
(CCA) and CCAA was drafted by a team including the Service, BLM, Center
of Excellence for Hazardous Material Management (CEHMM), and
participating cooperators to address the conservation needs of the
lesser prairie-chicken and the dunes sagebrush lizard. Since the CCA
and CCAA were finalized in 2008, 43 oil and gas companies have enrolled
a total of 1,964,163 ac (794,868 ha) in the historical range of the
lesser prairie-chicken. In addition, 72 ranchers in New Mexico and the
New Mexico Department of Game and Fish have enrolled a total of
2,055,461 ac (831,815 ha). The New Mexico State Land Office has
enrolled a total of 406,673 ac (164,575 ha) in the historical range of
the lesser prairie-chicken. The CCA and CCAA have treated 79,297 ac
(32,090 ha) of mesquite and reclaimed 154 abandoned well pads and
associated roads. CEHMM has also removed 7,564 ac (3,061 ha) of dead,
standing mesquite, and has another 12,000 ac (5,000 ha) scheduled in
the upcoming 2 years.
The Nature Conservancy owns and manages the 28,000-ac (11,331-ha)
Milnesand Prairie Preserve near Milnesand, New Mexico. Additionally,
the New Mexico Department of Game and Fish has designated 30 Prairie
Chicken Areas (PCAs) specifically for management of the lesser prairie-
chicken ranging in size from 28 to 7,189 ac (11 to 2,909 ha) and
totaling more than 27,262 ac (11,033 ha). In 2007, the State Game
Commission used New Mexico State Land Conservation Appropriation
funding to acquire 5,285 ac (2,137 ha) of private ranchland in
Roosevelt County. The Service's PFW program in New Mexico has
contributed financial and technical assistance for restoration and
enhancement activities benefitting the lesser prairie-chicken in New
Mexico. In 2016, the PFW program executed a private land agreement on
630 ac (255 ha) for treating invasive species with a prescribed burn.
In 2020 the PFW program executed a private land agreement for a
prescribed burn on 155 ac (63 ha).
Conditions and Trends
Rangewide Trends
The lesser prairie-chicken estimated historical range encompasses
an area of approximately 115 million ac (47 million ha). As discussed
in Background, not all of the area within this historical range was
evenly occupied by lesser prairie-chicken, and some of the area may not
have been suitable to regularly support lesser prairie-chicken
populations (Boal and Haukos 2016, p. 6). However, the current range of
the lesser prairie-chicken has been significantly reduced from the
historical range, and estimates of the reduction vary from greater than
90 percent (Hagen and Giesen 2005, unpaginated) to approximately 83
percent (Van Pelt et al. 2013, p. 3).
We estimated the current amount and configuration of potential
lesser prairie-chicken usable area within the analysis area using the
geospatial analysis described in the SSA report (Service 2021, Section
3.2; Appendix B, Parts 1, 2, and 3) and considering existing impacts as
described above. The total area of all potential usable (land cover
that may be consistent with lesser prairie-chicken areas that have the
potential to support lesser prairie-chicken use) and potential usable,
unimpacted land cover (that is, not impacted by landscape features)
categories in each ecoregion and rangewide is shown in Table 1.
To assess lesser prairie-chicken habitat at a larger scale and
incorporate some measure of connectivity and fragmentation, we then
grouped the areas of potential usable, unimpacted land cover based on
the proximity of other areas with potential usable, unimpacted lesser
prairie-chicken land cover. To do this, we used a ``nearest neighbor''
geospatial process to determine how much potential usable land cover is
within 1 mi (1.6 km) of any area of potential usable land cover. This
nearest neighbor analysis gives an estimate of how closely potential
usable, unimpacted land cover is clustered together, versus spread
apart, from other potential usable, unimpacted land cover. Areas with
at least 60 percent potential usable, unimpacted land cover within 1 mi
(1.6 km) were grouped. The 60 percent threshold was chosen because
maintaining grassland in large blocks is vital to conservation of the
species (Ross et al. 2016a, entire; Hagen and Elmore 2016, entire;
Spencer et al. 2017, entire; Sullins et al. 2019, entire), and these
studies indicate that landscapes consisting of greater than 60%
grassland are required to support lesser prairie-chicken populations.
This approach eliminates small, isolated, and fragmented patches of
otherwise potential usable land cover that are not likely to support
persistent populations of the lesser prairie-chicken. A separate
analysis found that the areas with 60 percent or greater unimpacted
potential usable land cover within 1 mile (1.6 km) captured
approximately 90 percent of known leks (Service 2021, Appendix B, Part
3).

[[Page 29457]]

Table 1--Results of Lesser Prairie-Chicken Geospatial Analysis by Ecoregion and Rangewide, Estimating Total Area
in Acres, Potential Usable Area, and Area Calculated by Our Nearest Neighbor Analysis
[All numbers are in acres. Numbers may not sum due to rounding.]
----------------------------------------------------------------------------------------------------------------
Nearest
Ecoregion Ecoregion Potential neighbor Percent of
total area usable area analysis total area
----------------------------------------------------------------------------------------------------------------
Short-Grass/CRP................................. 6,298,014 2,961,318 1,023,894 16.3
Mixed-Grass..................................... 8,527,718 6,335,451 994,483 11.7
Sand Sagebrush.................................. 3,153,420 1,815,435 1,028,523 32.6
---------------------------------------------------------------
Northern DPS total.......................... 17,979,152 11,112,204 3,046,900 16.9
Shinnery Oak (Southern DPS total)........... 3,850,209 2,626,305 1,023,572 26.6
---------------------------------------------------------------
Rangewide Totals........................ 21,829,361 13,738,509 4,070,472 18.6
----------------------------------------------------------------------------------------------------------------

The results of the nearest neighbor analysis indicate that about 19
percent of the entire analysis area and from 12 percent to 33 percent
within each of the four ecoregions is available for use by the lesser
prairie-chicken. Due to limitations in data availability and accuracy
as well as numerous limitations with the methodology and assumptions
made for this analysis, this estimate should not be viewed as a precise
measure of the lesser prairie-chicken habitat; instead, it provides a
generalized baseline to characterize the current condition and by which
we can then forecast the effect of future changes.
In the SSA report, we also considered trends in populations.
Estimates of population abundance prior to the 1960s are indeterminable
and rely almost entirely on anecdotal information (Boal and Haukos
2016, p. 6). While little is known about precise historical population
sizes, the lesser prairie-chicken was reported to be quite common
throughout its range in the early 20th century (Bent 1932, pp. 280-281,
283; Baker 1953, p. 8; Bailey and Niedrach 1965, p. 51; Sands 1968, p.
454; Fleharty 1995, pp. 38-44; Robb and Schroeder 2005, p. 13). In the
1960s, State fish and wildlife agencies began routine lesser prairie-
chicken monitoring efforts that have largely continued to today.
In the SSA report and this proposed rule, we discuss lesser
prairie-chicken population estimates from two studies. The first study
calculated historical trends in lesser prairie-chicken abundances from
1965 through 2016 based on population reconstruction methods and
historical lek surveys (Hagen et al. 2017, pp. 6-9). The results of
these estimates indicate that lesser prairie-chicken rangewide
abundance (based on a minimum estimated number of male lesser prairie-
chicken) peaked from 1965-1970 at a mean estimate of about 175,000
males. The mean population estimates maintained levels of greater than
100,000 males until 1989, after which they steadily declined to a low
of 25,000 males in 1997 (Garton et al. 2016, p. 68). The mean
population estimates following 1997 peaked again at about 92,000 males
in 2006 but subsequently declined to 34,440 males in 2012. The Service
identified concerns in the past with some of the methodologies and
assumptions made in this analysis, and the challenges of these data are
noted in other studies (for example, Zavaleta and Haukos 2013, p. 545;
Cummings et al. 2017, pp. 29-30). While these concerns remain,
including the very low sample sizes particularly in the 1960s, this
work represents the only attempt to compile the extensive historical
ground lek count data collected by State agencies to estimate rangewide
population sizes. Approximate distribution of lek locations as reported
by WAFWA for the entire range that were observed occupied by lesser
prairie-chicken at least once between 2015 and 2019 are shown in the
SSA report (Service 2021, Appendix E, Figure E.7).
Following development of aerial survey methods (McRoberts et al.
2011, entire), more statistically rigorous estimates of lesser prairie-
chicken abundance (both males and females) have been conducted by
flying aerial line-transect surveys throughout the range of the lesser
prairie-chicken and extrapolating densities from the surveyed area to
the rest of the range beginning in 2012 (Nasman et al. 2020, entire).
The aerial survey results from 2012 through 2020 (Service 2021, Figure
3.2) estimated the lesser prairie-chicken population abundance,
averaged over the most recent 5 years of surveys (2015-2020, no surveys
in 2019), at 27,384 (90 percent CI: 15,690, 59,981) (Nasman et al.
2020, p. 21; Table 2). The results of these survey efforts should not
be taken as precise estimates of the annual lesser prairie-chicken
population abundance, as indicated by the large confidence intervals.
Thus, the best use of this data is for long-term trend analysis rather
than for conclusions based on annual fluctuations. As such, we report
the population estimate for the current condition as the average of the
past 5 years of surveys.

Table 2--Rangewide and Ecoregional Estimated Lesser Prairie-Chicken Total Population Sizes Averaged From 2015 to
2020, Lower and Upper 90 Percent Confidence Intervals (CI) Over the 5 Years of Estimates, and Percent of
Rangewide Totals for Each Ecoregion (From Nasman et al. 2020, p. 21). No Surveys Were Conducted in 2019
----------------------------------------------------------------------------------------------------------------
5-Year 5-Year 5-Year
Ecoregion average minimum lower maximum upper Percent of
estimate CI CI total
----------------------------------------------------------------------------------------------------------------
Short-Grass/CRP................................. 16,957 13,605 35,350 62
Mixed-Grass..................................... 6,135 1,719 11,847 22
Sand Sagebrush.................................. 1,215 196 4,547 4
Shinnery Oak.................................... 3,077 170 8,237 11
---------------------------------------------------------------

[[Page 29458]]

Rangewide Totals............................ 27,384 15,690 59,981 100
----------------------------------------------------------------------------------------------------------------

We now discuss habitat impacts and population trends in each
ecoregion and DPS throughout the range of the lesser prairie-chicken.
Southern DPS
Using our geospatial analysis, we were able to explicitly account
for habitat loss and fragmentation and quantify the current condition
of the Shinnery Oak Ecoregion. Of the sources of habitat loss and
fragmentation that have occurred, cropland conversion, roads, and
encroachment of woody vegetation had the largest impacts on land cover
in the Southern DPS (Table 3). Based on our nearest neighbor analysis,
we estimated there are approximately 1,023,572 ac (414,225 ha) or 27
percent of the ecoregion and the Southern DPS potentially available for
use by lesser prairie-chicken (Table 1).

Table 3--Estimated Areas of Current Direct and Indirect Impacts, by
Impact Source, and the Proportion of the Total Area of the Shinnery Oak
Ecoregion Estimated To Be Impacted (See Table 1 for Totals)
[Impacts are not necessarily cumulative because of overlap of some
impacted areas by more than one impact source.]
------------------------------------------------------------------------
Shinnery Oak Ecoregion (Southern DPS)
-------------------------------------------------------------------------
Percent of
Impact sources Acres ecoregion
------------------------------------------------------------------------
Cropland Conversion..................... 540,120 14
Petroleum Production.................... 161,652 4
Wind Energy Development................. 90,869 2
Transmission Lines...................... 372,577 10
Woody Vegetation Encroachment........... 617,885 16
Roads................................... 742,060 19
-------------------------------
Total Ecoregion/Southern DPS Area... 3,850,209
------------------------------------------------------------------------

Based on population reconstruction methods, the mean population
estimate ranged between about 5,000 to 12,000 males through 1980,
increased to 20,000 males in the mid-1980s and declined to ~1,000 males
in 1997 (Hagen et al. 2017, pp. 6-9). The mean population estimate
peaked again to ~15,000 males in 2006 and then declined again to fewer
than 3,000 males in the mid-2010s.
Aerial surveys have been conducted to estimate lesser prairie-
chicken population abundance since 2012, and results in the Shinnery
Oak Ecoregion from 2012 through 2020 (Service 2021, Figure 3.10)
indicate that this ecoregion has the third highest population size
(Nasman et al. 2020, p. 21) of the four ecoregions. Average estimates
from 2015 to 2020 are 3,077 birds (90 percent CI: 170, 8,237),
representing about 11 percent of the rangewide total (Table 2). Recent
estimates have varied between fewer than 1,000 birds in 2015 to more
than 5,000 birds in 2020 (see also Service 2021, Appendix E, Figure
E.7).
Northern DPS
Prairies of the Short-Grass/CRP Ecoregion have been significantly
altered since European settlement of the Great Plains. Much of these
prairies have been converted to other land uses such as cultivated
agriculture, roads, power lines, petroleum production, wind energy, and
transmission lines. Some areas have also been altered due to woody
vegetation encroachment. Within this ecoregion, it has been estimated
that about 73 percent of the landscape has been converted to cropland
with 7 percent of the area in CRP (Dahlgren et al. 2016, p. 262).
According to our GIS analysis, of the sources of habitat loss and
fragmentation that have occurred, conversion to cropland has had the
single largest impact on land cover in this ecoregion (Table 4). Based
on our nearest neighbor analysis, we estimated approximately 1,023,894
ac (414,355 ha), or 16 percent of the ecoregion, is potentially
available for use by lesser prairie-chicken (Table 1).

Table 4--Estimated Areas of Current Direct and Indirect Impacts, by
Impact Source, and the Proportion of the Total Area of the Short-Grass/
CRP Ecoregion Estimated To Be Impacted (See Table 1 for Totals)
[Impacts are not necessarily cumulative because of overlap of some
impacted areas by more than one impact source.]
------------------------------------------------------------------------
Short-Grass/CRP Ecoregion
-------------------------------------------------------------------------
Percent of
Impact sources Acres ecoregion
------------------------------------------------------------------------
Cropland Conversion..................... 2,333,660 37
Petroleum Production.................... 248,146 4

[[Page 29459]]

Wind Energy Development................. 145,963 2
Transmission Lines...................... 436,650 7
Woody Vegetation Encroachment........... 284,175 5
Roads................................... 1,075,931 17
-------------------------------
Total Ecoregion Area................ 6,298,014
------------------------------------------------------------------------

Based on population reconstruction methods, the mean population
estimate for this ecoregion increased from a minimum of about 14,000
males in 2001 and peaked at about 21,000 males in 2011 (Hagen et al.
2017, pp. 8-10; see also Service 2021, Figure 3.3).
Aerial surveys since 2012 indicate that the Short-Grass/CRP
Ecoregion (Figure 3.4) has the largest population size (Nasman et al.
2020, p. 21) of the four ecoregions. Average estimates from 2015 to
2020 are 16,957 birds (90 percent CI: 13,605, 35,350), making up about
62 percent of the rangewide lesser prairie-chicken total (Table 2).
Much of the Mixed-Grass Ecoregion was originally fragmented by
home-steading, which subdivided tracts of land into small parcels of
160-320 ac (65-130 ha) in size (Rodgers 2016, p. 17). As a result of
these small parcels, road and fence densities are higher compared to
other ecoregions and, therefore, increase habitat fragmentation and
pose higher risk for collision mortalities than in other ecoregions
(Wolfe et al. 2016, p. 302). Fragmentation has also occurred due to oil
and gas development, wind energy development, transmission lines,
highways, and expansion of invasive woody plants such as eastern red
cedar. A major concern for lesser prairie-chicken populations in this
ecoregion is the loss of grassland due to the rapid westward expansion
of the eastern red-cedar (NRCS 2016, p. 16). Oklahoma Forestry Services
estimated the average rate of expansion of eastern red-cedar in 2002 to
be 762 ac (308 ha) per day (Wolfe et al. 2016, p. 302).

Table 5--Estimated Areas of Current Direct and Indirect Impacts, by
Impact Source, and the Proportion (%) of the Total Area of the Mixed-
Grass Ecoregion Estimated To Be Impacted (See Table 1 for Totals)
[Impacts are not necessarily cumulative because of overlap of some
impacted areas by more than one impact source.]
------------------------------------------------------------------------
Mixed-Grass Ecoregion
-------------------------------------------------------------------------
Percent of
Impact sources Acres ecoregion
------------------------------------------------------------------------
Cropland Conversion..................... 1,094,688 13
Petroleum Production.................... 859,929 10
Wind Energy Development................. 191,571 2
Transmission Lines...................... 576,713 7
Woody Vegetation Encroachment........... 2,047,510 24
Roads................................... 1,732,050 20
-------------------------------
Total Ecoregion Area................ 8,527,718
------------------------------------------------------------------------

Using our geospatial analysis, we were able to explicitly account
for habitat loss and fragmentation and quantify the current condition
of this ecoregion for the lesser prairie-chicken. Of the sources of
habitat loss and fragmentation that have occurred, encroachment of
woody vegetation had the largest impact, with conversion to cropland,
roads, and petroleum production also having significant impacts on land
cover in this ecoregion (Table 5). Based on our nearest neighbor
analysis, we estimated there are approximately 994,483 ac (402,453 ha)
or 12 percent of the ecoregion, that is potentially available for use
by lesser prairie-chicken (Table 1).
The Mixed-Grass Ecoregion historically contained the highest lesser
prairie-chicken densities (Wolfe et al. 2016, p. 299). Based on
population reconstruction methods, the mean population estimate for
this ecoregion in the 1970s and 1980s was around 30,000 males (Hagen et
al. 2017, pp. 6-7). Population estimates declined in the 1990s and
peaked again in the early 2000s at around 25,000 males, before
declining and remaining at its lowest levels, <10,000 males in 2012,
since the late 2000s (Hagen et al. 2017, pp. 6-7).
Aerial surveys from 2012 through 2020 (Service 2021, Figure 3.6)
indicate this ecoregion has the second highest population size of the
four ecoregions (Nasman et al. 2020, p. 21). Average estimates from
2015 to 2020 are 6,135 birds (90 percent CI: 1,719, 11,847),
representing about 22 percent of the rangewide total (Table 2). Results
show minimal variation in recent years.
Prairies of the Sand Sagebrush Ecoregion have been influenced by a
variety of activities since European settlement of the Great Plains.
Much of these grasslands have been converted to other land uses such as
cultivated agriculture, roads, power lines, petroleum production, wind
energy, and transmission lines. Some areas have also been altered due
to woody vegetation encroachment. Only 26 percent of historical sand
sagebrush prairie is

[[Page 29460]]

available as potential nesting habitat for lesser prairie-chicken
(Haukos et al. 2016, p. 285). Using our geospatial analysis, we were
able to explicitly account for habitat loss and fragmentation and
quantify the current condition of this ecoregion for the lesser
prairie-chicken. Of the sources of habitat loss and fragmentation that
have occurred, conversion to cropland has had the single largest impact
on land cover in this ecoregion (Table 6). Based on our nearest
neighbor analysis, we estimated there are approximately 1,028,523 ac
(416,228 ha) or 33 percent of the ecoregion, potentially available for
use by lesser prairie-chicken (Table 1). In addition, habitat loss due
to the degradation of the rangeland within this ecoregion continues to
be a limiting factor for lesser prairie-chicken, and most of the
existing birds within this ecoregion persist primarily on and near CRP
lands. Drought conditions in the period 2011-2014 have expedited
population decline (Haukos et al. 2016, p. 285).

Table 6--Estimated Areas of Current Direct and Indirect Impacts, by
Impact Source, and the Proportion (%) of the Total Area of the Sand
Sagebrush Ecoregion Estimated To Be Impacted (See Table 1 for Totals)
[Impacts are not necessarily cumulative because of overlap of some
impacted areas by more than one impact source.]
------------------------------------------------------------------------
Sand Sagebrush Ecoregion
-------------------------------------------------------------------------
Percent of
Impact sources Acres ecoregion
------------------------------------------------------------------------
Cropland Conversion..................... 994,733 32
Petroleum Production.................... 163,704 5
Wind Energy Development................. 0 0
Transmission Lines...................... 167,240 5
Woody Vegetation Encroachment........... 68,147 2
Roads................................... 446,316 14
-------------------------------
Total Ecoregion Area................ 3,153,420
------------------------------------------------------------------------

Based on population reconstruction methods, the mean population
estimate for this ecoregion peaked at >90,000 males from 1970 to 1975
and declined to its lowest level of fewer than 1,000 males in recent
years.
Aerial surveys from 2012 through 2020 indicate that this ecoregion
has the lowest population size (Nasman et al. 2020, p. 21) of the four
ecoregions. Average estimates from 2015 to 2020 are 1,215 birds (90
percent CI: 196, 4,547) representing about 4 percent of the rangewide
lesser prairie-chicken total (Table 2). Recent results have been highly
variable, with 2020 being the lowest estimate reported. Although the
aerial survey results show 171 birds in this ecoregion in 2020, (with
no confidence intervals because the number of detections were too low
for statistical analysis), ground surveys in this ecoregion in Colorado
and Kansas detected 406 birds, so we know the current population is
actually larger than indicated by the aerial survey results (Rossi and
Fricke, pers. comm. 2020, entire).
Table 7 combines the estimated area impacted presented above for
each of the three ecoregions into one estimate for each impact source
for the Northern DPS.

Table 7--Estimated Areas of Current Direct and Indirect Impacts, by
Impact Source, and the Proportion (%) of the Total Area of the Northern
DPS Estimated To Be Impacted (See Table 1 for Totals)
[Impacts are not necessarily cumulative because of overlap of some
impacted areas by more than one impact source.]
------------------------------------------------------------------------
Northern DPS
-------------------------------------------------------------------------
Impact sources Acres Percent of DPS
------------------------------------------------------------------------
Cropland Conversion..................... 4,423,081 25
Petroleum Production.................... 1,271,779 7
Wind Energy Development................. 337,534 2
Transmission Lines...................... 1,180,603 7
Woody Vegetation Encroachment........... 2,399,832 13
Roads................................... 3,254,297 18
-------------------------------
Total Northern DPS Area............. 17,979,152
------------------------------------------------------------------------

Future Condition
As discussed above, we conducted a geospatial analysis to
characterize the current condition of the landscape for the lesser
prairie-chicken by categorizing land cover data (into potential usable,
potential restoration, or non-usable categories), taking into account
exclusion areas and impacts to remove non-usable areas. We further
refined the analysis to account for connectivity by use of our nearest
neighbor analysis as described in Rangewide Trends. We then used this
geospatial framework to analyze the future condition for each
ecoregion. To analyze future habitat changes, we accounted for the
effects of both future loss of usable areas and restoration efforts by
estimating the rate of change based on future projections (Service
2021, Figure 4.1).
Due to uncertainties associated with both future conservation
efforts and impacts, it is not possible to precisely quantify the
effect of these future actions on the landscape. Instead, we

[[Page 29461]]

established five future scenarios to represent a range of plausible
outcomes based upon three plausible levels of conservation (restoration
efforts) and three plausible levels of impacts. To account for some of
the uncertainty in these projections, we combined the levels of impacts
into five different scenarios labeled 1 through 5 (Table 8). Scenario 1
represents the scenario with low levels of future impacts and high
levels of future restoration, and Scenario 5 represents the scenario
with high impacts and low restoration. Scenario 1 and 5 were used to
frame the range of projected outcomes used in our model as they
represent the low and high of likely projected outcomes. Scenarios 2,
3, and 4 are model iterations that fall within the range bounded by
scenarios 1 and 5 and have continuation of the current level of
restoration efforts and vary impacts at low, mid, and high levels,
respectively. These scenarios provide a wide range of potential future
outcomes to consider in assessing lesser prairie-chicken habitat
conditions.

Table 8--Schematic of Future Scenarios for Lesser Prairie-Chicken
Conservation Considering a Range of Future Impacts and Restoration
Efforts
------------------------------------------------------------------------
Levels of future change in usable area
Scenario ----------------------------------------------
Restoration Impacts
------------------------------------------------------------------------
1........................ High.................... Low.
2........................ Continuation............ Low.
3........................ Continuation............ Mid.
4........................ Continuation............ High.
5........................ Low..................... High.
------------------------------------------------------------------------

To project the likely future effects of impacts and conservation
efforts to the landscape as described through our land cover model, we
quantified the three levels of future habitat restoration and three
levels of future impacts within the analysis area by ecoregion on an
annual basis. In addition to restoration efforts, we also quantified
those efforts that enhance existing habitat. While these enhancement
efforts do not increase the amount of available area and thus are not
included in the spatial analysis, they are summarized in the SSA report
and considered as part of the overall analysis of the biological status
of the species. We then extrapolated those results over the next 25
years. We chose 25 years as a period for which we had reasonable
confidence in reliably projecting these future changes, and the
timeframe corresponds with some of the long-term planning for the
lesser prairie-chicken. A complete description of methodology used to
quantify projections of impacts and future conservation efforts is
provided in the SSA report (Service 2021, Appendix C).
Quantifying future conservation efforts in terms of habitat
restoration allows us to account for the positive impact of those
efforts within our analysis by converting areas of land cover that were
identified as potential habitat in our current condition model to
usable land cover for the lesser prairie-chicken in the future
projections. Explicitly quantifying three levels of impacts in the
future allows us to account for the effect of these impacts on the
lesser prairie-chicken by converting areas identified as usable land
cover in our current condition model to nonusable area that will not be
available for use by the lesser prairie-chicken in the future.
As we did for the current condition to assess habitat connectivity,
after we characterized the projected effects of conservation and
impacts on potential future usable areas, we grouped the areas of
potential usable, unimpacted land cover on these new future landscape
projections using our nearest neighbor analysis (Service 2021, pp. 21-
24; Appendix B, Parts 1, 2, and 3). Also, as done for the current
condition, we evaluated the frequency of usable area blocks by size in
order to evaluate habitat fragmentation and connectivity in the future
scenarios (Service 2021, Figure 4.2).
Threats Influencing Future Condition
Following are summary evaluations of the expected future condition
of threats analyzed in the SSA for the lesser prairie-chicken: Effects
associated with habitat degradation, loss, and fragmentation, including
conversion of grassland to cropland (Factor A), petroleum production
(Factor A), wind energy development and transmission (Factor A), woody
vegetation encroachment (Factor A), and roads and electrical
distribution lines (Factor A); climate change (Factor A); and other
factors, such as livestock grazing (Factor A), shrub control and
eradication (Factor A), fire (Factor A); and climate change (Factor E).
In this proposed rule, we do not present summary evaluations of the
following threats as we have no information to project future trends,
though we do expect them to have some effect on the species in the
future: Predation (Factor C), collision mortality from fences (Factor
E), and influence of anthropogenic noise (Factor E). We also do not
discuss the following threats, as they are having little to no impact
on the species and its habitat currently, nor do we expect them to into
the foreseeable future: Hunting and other recreational, educational,
and scientific use (Factor B); parasites and diseases (Factor C); and
insecticides (Factor E).
For the purposes of this assessment, we consider the foreseeable
future to be the amount of time on

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