Office of External Affairs
Mountain-Prairie Region


U.S. Fish and Wildlife Service
Mountain-Prairie Region
134 Union Boulevard
Lakewood, Colorado 80228

June 5, 2012

Susan Linner, (303) 236-4773
Leith Edgar, (303) 236-4588;  

U.S. Fish and Wildlife Service to Initiate Status Reviews of Southern, Mt. Rainier White-tailed Ptarmigan

White-tailed Ptarmigan in Summer Plumage  Photo: Pete Plage
White-tailed Ptarmigan in Summer Plumage
Photo:Pete Plage USFWS

The U.S. Fish and Wildlife Service (Service) announced today that we have completed our evaluation of a petition to list the southern and Mt. Rainier white-tailed ptarmigan as threatened under the Endangered Species Act (ESA).  We determined that substantial biological information exists to warrant a more in-depth examination of the status of the southern and Mt. Rainier white-tailed ptarmigan. 

We will conduct a full status review of both subspecies of white-tailed ptarmigan, and once the review is complete, determine whether to propose adding the southern and/or Mt. Rainier white-tailed ptarmigan to the Federal lists of threatened or endangered wildlife and plants.  The southern white-tailed ptarmigan occurs in the Rocky Mountains of Colorado and New Mexico.  The Mt. Rainier white-tailed ptarmigan occurs in the North Cascade Mountains of Washington. 

The Service’s decision, commonly known as a 90-day finding, is based on scientific information about the species provided in a petition requesting the species be listed under the ESA.  The petition and supporting documents provided substantial information that the southern and Mt. Rainier white-tailed ptarmigan may be threatened by the loss and modification of alpine habitats due to global climate change.  Information in the petition also indicated that warming temperatures may depress population growth rates and increase susceptibility to heat stress.       

The finding on the petition does not mean that we have decided it is appropriate to list the southern or Mt. Rainier white-tailed ptarmigan.  Rather, this finding is the first step in a process to trigger a more thorough review of all the biological information available for both subspecies.   

To ensure the status review is comprehensive, we are soliciting information from State and Federal natural resource agencies and all interested parties regarding the southern and Mt. Rainier white-tailed ptarmigan and its habitat. 

Based on the status review, we will make one of three possible determinations:

  1. Protection under the ESA is not warranted, in which case no further action would be taken.

  2. Protection under the ESA as threatened or endangered is warranted.  In this case, we would publish a proposal to add the population to the list of threatened and endangered species and designate critical habitat (if prudent and determinable), solicit independent scientific peer review of the proposal, seek input from the public, and consider the input before a final decision about listing the species is made.  Generally, the final decision is made one year after the species is proposed.

  3. Protection under the ESA is warranted but precluded by higher priority activities.  This means the species would be added to the Federal list of candidate species, and the proposal to list would be deferred while the Service works on listing proposals for other species that are at greater risk.  A warranted but precluded finding requires subsequent annual reviews of the finding until such time as either a listing proposal is published, or a not warranted finding is made based on new information.

For more information on the southern and Mt. Rainier white-tailed ptarmigan and this finding, please visit the Service’s website at: For public domain imagery of the species, please visit this flickr gallery:

Anyone wishing to submit information regarding the southern or Mt. Rainier white-tailed ptarmigan may do so by writing to Public Comments Processing, Attn:  FWS-R6-ES-2012-0023; Division of Policy and Directives Management; U.S. Fish and Wildlife Service; 4401 N. Fairfax Drive, MS 2042–PDM; Arlington, VA 22203 or by electronic mail to  After accessing the website, in the box that reads “Enter Keyword or ID,” enter the docket number for this finding stated above.  Check the box that reads “Open for Comment/Submission,” and click the Search button.  Comments must be received by August 6, 2012.

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