Office of External Affairs
Mountain-Prairie Region


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

For Release on December 16, 2011             



Beth Dickerson 406-449-5225 x 220


U.S. Fish and Wildlife Service to Initiate a Status Review of the Western Glacier Stonefly

a stoneflyThe U.S. Fish and Wildlife Service announced today that it has completed its evaluation of a petition to list the western glacier stonefly as endangered and determined that substantial biological information exists to warrant a more in-depth examination of the species’ status.  Therefore, we will be conducting a full status review of the species, and once the review is complete, we will determine whether to propose adding the species to the federal lists of threatened or endangered wildlife and plants.  The western glacier stonefly is an aquatic insect known to occur only in glacier-fed streams in parts of Glacier National Park in Montana. 

The Service’s decision, commonly known as a 90-Day Finding, is based on scientific information about the species provided in a petition requesting listing of the species under the Endangered Species Act (ESA).  This finding will be published in the Federal Register on December 19, 2011.  The petition provided substantial information that habitat deterioration and loss may result from warming temperatures and altered precipitation regimes projected to occur with climate change.  Information was also provided that indicated the species may be affected by the vulnerability of small populations to random environmental events and the inadequacy of existing regulatory mechanisms regarding environmental changes due to climate change.

The finding on the petition does not mean that we have decided it is appropriate to list the western glacier stonefly.  Rather, this finding is the first step in a long process that triggers a more thorough review of all the biological information available.  This process includes a request for input from the public.  This status review will determine whether the western glacier stonefly warrants listing as a threatened or endangered species.

To ensure this status review is comprehensive, we are soliciting information from state and federal natural resource agencies and all interested parties regarding the western glacier stonefly and its habitat.  We are especially seeking information on whether the species is still in existence, as we have no documented records of it in approximately 30 years.

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 will be taken.

  2. Protection under the ESA as threatened or endangered is warranted.  In this case, the Service will publish a proposal to add the species to the list of threatened and endangered species, 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, there is a 1-year period between the time a species is proposed and the final decision.

  3. Protection under the ESA is warranted but precluded by other, higher priority activities.  This means the species is added to the federal list of candidate species, and the proposal to list is 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.

The western glacier stonefly is a member of the taxonomic order Plecoptera (commonly called stoneflies), which require cool, clean streams and lakes typical of high-elevation mountainous areas.  Eggs and larval (immature) forms of these insects are aquatic.  Adult stoneflies are found on rocks or other structures above the water either within the streambed or on stream-side vegetation.  There they mate and complete their short adult lifecycles with the females depositing fertilized eggs back to the stream.

Anyone wishing to submit information regarding the western glacier stonefly may do so by writing to Public Comments Processing, Attn: FWS–R6–ES–2011–0102, 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 February 17, 2012.

For more information about the western glacier stonefly and this finding, please visit the Service’s website at

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