The question of whether the lesser prairie-chicken, a species of bird native to southwestern grasslands and prairies, will retain its status as a listed species under the Endangered Species Act (“ESA”) remains in question as a lawsuit challenging its listing continues. The species was formally listed in late 2022. In 2023, the state of Texas filed a lawsuit to delist the lesser prairie-chicken. Although the United States Fish and Wildlife Service (“FWS”) originally fought the claim, in 2025 the agency asked the judge presiding over the case to undo the listing decision and dismiss the lawsuit. However, environmental groups seeking to intervene as parties in the case have argued that the court cannot vacate the decision to list the lesser prairie-chicken without first ruling on the merits of the case. While it is currently unclear whether the court will grant FWS’s request to vacate the decision to list the lesser prairie-chicken, the decision will impact farming and ranching operations located in areas where the birds are found.
Background
The lesser prairie-chicken is a species of bird whose historic range includes Southeastern Colorado, Southwestern Kansas, Western Oklahoma, the Panhandle and South Plains of Texas, and Eastern New Mexico. Currently, the bird only occupies a small percentage of its historic range, with some estimates suggesting that its range has been reduced by as much as 90%. Along with a reduction in its range, the lesser prairie-chicken has also seen its population levels decline since at least the 1960s. Habitat loss along with population decline has prompted FWS to recognize two distinct populations of lesser prairie-chicken, a southern population located in New Mexico and Texas, and a northern population located across Texas, Oklahoma, Colorado, and Kansas. While the two populations were at one point connected, FWS now considers them separate and distinct, which has been reflected in the agency’s listing decision for the species.
The ESA is the primary federal wildlife protection law in the United States. Its purpose is to converse both species facing the threat of extinction, and the ecosystems on which those species depend. To achieve this goal, FWS together with the National Marine Fisheries Service (collectively, “the Services”) are charged with identifying species that should be added to the federal list of endangered and threatened wildlife and plants and thus receive ESA protection. According to the ESA, the Services can list a species for any one of the following five reasons: (1) the present or threatened destruction, modification, or curtailment of the species’ habitat or range; (2) overutilization of the species for commercial, recreational, scientific, or educational purposes; (3) disease or predation; (4) inadequacy of existing regulatory mechanisms to otherwise protect the species; or (5) other natural or manmade factors affecting the species’ existence. 16 U.S.C. § 1533.
The Services can list a species under the ESA in its entirety, or they can list “any distinct population segment of any species[.]” 16 U.S.C. § 1532(16). While the ESA itself does not provide a definition for “distinct population segment,” the Services have issued guidance on how to interpret the term. According to the Policy Regarding the Recognition of Distinct Vertebrate Population Segments Under the Endangered Species Act (“DPS Policy”), the Services will consider the following three factors when determining whether a particular population of a species can be classified as a distinct population segment: (1) the discreteness of the population segment in relation to the remainder of the species to which it belongs; (2) the significance of the population segment to the species to which it belongs; and (3) the population segment’s conservation status in relation to the ESA’s standards for listing a species.
When listing the lesser prairie-chicken under the ESA, FWS ultimately chose to list the northern population and the southern population as separate distinct population segments. The southern distinct population segment (“Southern DPS”) was listed as endangered under the ESA, while the northern distinct population segment (“Northern DPS”) was listed as threatened. The decision was finalized in late December 2022. More information on the listing decision is available here. A lawsuit challenging the decision was filed a month later.
Current Status
In January 2023, the state of Texas filed State of Texas v. U.S. Dep’t of Interior, No. 7:23-cv-00047 (W.D. Tex. March 21, 2023) to challenge the listing decision for both the Southern and Northern DPS of lesser prairie-chicken. The state raised several arguments to challenge the listing decision, claiming that FWS had misapplied the DPS Policy, that it had failed to analyze the conservation efforts currently underway to protect the lesser prairie-chicken, and that specifically the listing of the Northern DPS exceeded FWS’s statutory authority. While FWS initially defended its decision to list both distinct population segments of lesser prairie-chicken under the ESA, the agency has since altered its stance and is now asking the court to vacate the final listing decision and send the matter back to FWS for further review. However, environmental groups seeking to intervene in the case have argued that the court cannot overturn the listing decision without ruling on the merits of the case.
In early May 2025, FWS filed a motion for voluntary vacatur of its decision to list the two DPS of lesser prairie-chicken under the ESA. In that motion, FWS claims that it has identified a “serious default” in the listing decision. Specifically, FWS has determined that it failed to provide “adequate justification and analysis” to support identifying two designated population segments of lesser prairie-chicken. According to FWS, the final listing decision found that both the Northern and Southern DPS were “significant” because loss of the Southern DPS would result in a significant gap in the species’ range. However, FWS believes that conclusion was made in error because the agency did not consider whether the gap in the lesser prairie-chicken’s range would actually be significant for the species, but instead “merely restated” that the two populations were physically separated by 95 miles. According to FWS, this error is significant enough to require the agency to undergo a new analysis of the lesser prairie-chicken, which would make it appropriate for the court to overturn the 2022 final listing decision.
However, environmental groups who have petitioned to intervene in the case disagree. In response to FWS’s motion to vacate, the environmental groups argue that the court cannot overturn the listing decision without first ruling on the merits of the case. The groups argue that a growing body of case law suggests that it is inappropriate for a court to overturn a final agency action without first determining that the action has violated the law. The groups cite a Ninth Circuit decision, Illinois v. Wheeler, 60 F.4th 583 (9th Cir. 2023) and a Sixth Circuit decision, Sierra Club v. U.S. EPA, 60 F.4th 1008 (6th Cir. 2023) which both conclude that granting a federal agency’s voluntary remand for vacatur without ruling on the merits is inappropriate because the federal Administrative Procedure Act requires that agencies use the same process to repeal a final rule as they do to issue the rule in the first place.
While the Fifth Circuit, the jurisdiction where the challenge to the lesser prairie-listing decision is located, has not ruled specifically on the matter, the environmental groups argue that the test courts in the Fifth Circuit usually apply to determine whether to vacate a final agency action would not support overturning the listing decision. According to the environmental groups, courts in the Fifth Circuit will only overturn an agency action if the agency made a “serious error.” Although FWS claims to have made a serious error in the final listing decision by only basing the designation of two distinct population segments of lesser prairie-chicken on the fact that the groups are separated by 95 miles, the environmental groups disagree. They claim instead that FWS based the designation on findings suggest that the Northern and Southern DPS of lesser prairie-chicken are genetically distinct, and that loss of the Southern DPS would reduce the species’ range by as much as 25%. The groups argue that these findings do not support the argument that FWS made a “serious error” in its final listing decision for the lesser prairie-chicken. For those reasons, the environmental groups assert that not only should the court not grant FWS’s for voluntary vacatur of the listing decision and should instead rule on the merits, but that even a ruling on the merits would show that the listing decision was not made in error and should not be overturned.
Going Forward
Although it is currently unclear how the court will ultimately rule, the outcome of this case could have broader implications for voluntary vacatur in the Fifth Circuit. If the court grants the request from FWS to vacate the rule, it would suggest that in that jurisdiction, courts could be open to granting an agency’s request to overturn a final agency action without determining whether the action complies with relevant federal law. This could create a split between the Fifth Circuit and other jurisdictions such as the Ninth and Sixth Circuits that have ruled against voluntary vacatur in the past. However, if the court agrees with the environmental groups and finds it necessary to review the merits of the case prior to overturning it, that would mean that unless the court finds the listing decision unlawful, the Northern and Southern DPS of lesser prairie-chicken would both remain protected under the ESA unless FWS went through the formal rulemaking process to delist them. Because it is not uncommon for new Presidential administrations to disagree with agency actions taken by previous administrations, the question of whether courts can grant voluntary vacatur without ruling on the merits of the underlying case has become increasingly important.
To view FWS’s motion for voluntary vacatur, click here.
To view the response from environmental groups, click here.
To view the text of the ESA, click here.
For more ESA resources from the National Agricultural Law Center, click here.