Wyoming Ecological Services
Mountain-Prairie Region

Federally Listed, Proposed & Candidate Species | Species of Concern | Migratory Birds | All Species By County



Federally Listed, Proposed and Candidate Species


Black-footed Ferret
(Mustela nigripes)

Status: Experimental

Black-footed FerretPhoto Credit: FWS

On March 6, 2013, the U.S. Fish and Wildlife Service (Service) issued a letter acknowledging ‘block clearance’ for the State of Wyoming  in response to a request from the Wyoming Game and Fish Department.  This letter provides acknowledgement that the likelihood of identifying wild ferrets in Wyoming, outside of those resulting from reintroductions, is distinctly minimal.  The letter, and the analysis provided by the Wyoming Game and Fish Department, notes that despite improvements in knowledge, technology, survey techniques, and use of reward programs, there have been no verified reports of any extant black-footed ferret individuals or populations in any prairie dog complex since the discovery of a wild black-footed ferret population in 1981.  It further states  that it is unlikely that black-footed ferret populations in Wyoming have persisted through drastic reductions of prairie dog complexes, and that the black-footed ferret populations have not rebounded as prairie dog complexes have begun to expand again.

Consequently, the Service no longer recommends surveys for the black-footed ferrets in either black- or white-tailed prairie dog towns in the State of Wyoming.  We recommend that project proponents and Federal action agencies protect all prairie dog towns or complexes for their value to the prairie ecosystem and the many species that rely on them, and that they evaluate potentially disturbed prairie dog towns for their value to future black-footed ferret reintroduction.


Experimental Population

Experimental (Shirley Basin) population: Black-footed ferrets (Mustela nigripes) in the Shirley Basin/Medicine Bow Management Area are designated as a non-essential experimental population under the Act.  Although such black-footed ferrets are listed and protected under the Act, additional management flexibility is provided under the special regulations for this population (50 CFR 17.84(g) and 56 FR 41473).  Requirements for interagency consultation under section 7 of the Act differ based on the land ownership and/or management responsibility where the animals occur.  In the Shirley Basin non-essential experimental population, Federal agencies must confer with the Service on actions that are likely to jeopardize the continued existence of the species.  In addition to conferencing under section 7, Federal agencies have obligations under the provisions of section 7(a)(1) to utilize their authorities in furtherance of the purposes of the Act by carrying out programs for the conservation of endangered and threatened species (16 U.S.C 1536(a)(1)).  Agencies have discretion in selecting programs to conserve listed species.  We encourage Federal agencies and others to consider ways to further the conservation of the non-essential experimental population of the black-footed ferret in the Shirley Basin/Medicine Bow Management Area.

For Species Lists, please use the IPaC System

Area Of Influence

Areas Of Influence (AOI) identify areas where any project located within should consider potential effects to the Threatened, Endangered, Proposed, and Candidate species and designated and proposed Critical Habitat, in reference to Section 7 of the Endangered Species Act of 1973, as amended.  AOI typically encompass larger areas than simply where the species is known to exist because of direct and indirect effects to the species and their habitat.  It is important to consider potential effects to the species and their habitat within these larger areas.  Action agencies are encouraged to refer to the Service’s Information, Planning, and Conservation System (IPAC) or contact the FWS Wyoming Ecological Services Office for additional information.  (AOI boundaries based on the best available data at time of development.  AOI will be updated as new information becomes available).


Potential distribution of Experimental Black-footed Ferret in Wyoming
Download Area Of Influence GIS Data or Area Of Influence Google Earth layers
Section 7 Range Symbol Wyoming Area Of Influence
Black-footed Ferret


Recent Actions

On April 10, 2015, the U.S. Fish and Wildlife Service (Service) published a proposal to establish a non-essential, experimental 10(j) area for the black-footed ferret throughout the state of Wyoming.  This announcement opens a 60-day public comment period, which closes on June 9, 2015.  A 10(j) designation under the Endangered Species Act (ESA) would increase management flexibility and lessen regulatory requirements related to future ferret reintroductions in the state of Wyoming.  The goal of this proposal is to help facilitate new reintroductions of the black-footed ferret. 

Last updated: April 10, 2015