Office of External Affairs
Mountain-Prairie Region


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

November 1, 2007

Contact:  Diane Katzenberger 303-236-4578



Public Hearings Scheduled in Colorado and Wyoming


The U.S. Fish and Wildlife Service today proposed to remove Preble’s meadow jumping mouse populations in Wyoming from the list of species protected under the Endangered Species Act after analysis found that those populations are not likely to become threatened or endangered in the foreseeable future. The Service also proposed to amend the listing for Preble’s to indicate the subspecies remains threatened in the Colorado portion of its range.

Today’s proposal is based on a better understanding of the distribution of and threats to Preble’s meadow jumping mouse populations in Wyoming and Colorado. The Service has revised its 2005 proposal to delist the Preble’s across its entire range, which was based upon a genetic analysis that suggested the mouse was not a valid subspecies. The best commercial and scientific information currently available demonstrates that the Preble’s meadow jumping mouse is a valid subspecies and should not be removed from the Federal List of Threatened and Endangered Species based upon taxonomic revision.

“Since the Preble’s meadow jumping mouse was first listed in 1998, our biologists have learned more about its distribution, biology, population status and the threats it faces. This proposal affirms that the Preble’s meadow jumping mouse is a distinct genetic subspecies and emphasizes protecting the species where it is truly at risk of becoming endangered,” said Steve Guertin, the Service’s Acting Director for the Mountain-Prairie Region. “The Service will continue to work with our partners to implement conservation actions that will benefit the mouse and help us achieve healthy populations across its entire range.”

New distributional data and a better understanding of threats to the mouse have altered the Service’s understanding of the subspecies’ status in the Wyoming portion of its range.  At the time of listing, the Preble’s meadow jumping mouse was known from only a few sites in Wyoming.  Since then, additional distributional data has verified that Preble’s populations occur and appear secure throughout the North Platte River basin.  Land use across Preble’s habitat in Wyoming is dominated by agriculture, mostly haying and grazing.  Continuation of these long-standing activities does not appear to pose a threat to existing Preble’s populations.  In addition, there is also no indication that these agricultural practices are likely to change in the foreseeable future in ways that would affect Preble’s populations.  A low projected human population growth rate is predicted for the four Wyoming counties (Albany, Laramie, Platte, and Converse) that support Preble’s populations.  Consequently, few of the development-related impacts occurring in Colorado’s portion of the Front Range urban corridor will impact Preble’s populations in Wyoming. 

Based on a better understanding of the distribution and threats regarding Preble’s populations in Wyoming, the Service concluded that these populations are unlikely to become endangered in the foreseeable future.  The Service is, therefore, proposing to remove the Preble’s populations in the Wyoming portion of its range from the list of threatened and endangered species.

After determining that that the Preble’s meadow jumping mouse does not meet the definition of threatened or endangered across all of its range, the Service evaluated whether Preble’s meets the criteria to be listed as threatened or endangered in any significant portion of its range. A portion of the Preble’s meadow jumping mouse range may be found to be significant if it is part of the subspecies’ current range and supports populations that contribute meaningfully to the subspecies’ ability to maintain its genetic diversity and viability, and its ability to withstand random and catastrophic events.

In much of the Preble’s range in Colorado, development activities have severely altered or destroyed riparian habitat.  With current and projected human population increases and corresponding increases in urban and rural development, the ongoing loss and modification of riparian habitat will continue in much of the Preble’s range in Colorado. The Service believes that the loss of Preble’s populations in Colorado as a result of habitat loss and modification would meaningfully decrease the ability to conserve the subspecies.  Without the protection of the Endangered Species Act, most of the remaining habitat will be lost or altered within the foreseeable future.  Based on its importance to the conservation of the Preble’s meadow jumping mouse, the Service has determined that the Colorado portion of the range constitutes a significant portion of the mouse’s range. The Service is proposing to amend the endangered species listing for the Preble’s meadow jumping mouse to indicate that the subspecies remains threatened in the Colorado portion of its range.

Foreseeable future is defined by the Service on a case-by-case basis, taking into account a variety of species-specific factors.  For the purposes of this finding, foreseeable future is based on future development intensity since this is likely to be the single greatest factor affecting Preble’s populations.  In the Service’s view, the foreseeable future for this finding, based on the currently available data, extends to 2040. 

The Preble's meadow jumping mouse is found along the foothills in southeastern Wyoming southward along the eastern edge of the Front Range of Colorado to Colorado Springs in El Paso County, Colorado.  It inhabits well-developed plains riparian vegetation with relatively undisturbed grassland communities and a nearby water source.  It has been found to use uplands at least as far out as 100 meters beyond the 100-year flood plain. Habitat alteration, degradation, loss, and fragmentation resulting from urban development, flood control, water development, agriculture, and other human land uses have adversely impacted Preble’s populations.

The Preble’s meadow jumping mouse is a small mammal with a long tail, large hind feet, and long hind legs.  Total length of an adult is approximately 7 to 10 inches, with the tail comprising approximately 60 percent of that length.  To evade predators, the mouse can jump up to three feet. 

The Service intends that any final action resulting from today’s proposal be as accurate as possible and is seeking comments from the public.  Comments submitted for the 2005 proposal need not be resubmitted, as they have already been incorporated into the public record and will be fully considered in the final determination.

Written comments can be sent to the Field Supervisor, Colorado Field Office, Ecological Services, P.O. Box 25486, Denver Federal Center, Denver, Colorado 80225, or hand delivered to the Colorado Field Office at 134 Union Boulevard, Suite 670, Lakewood, Colorado 80228.  Comments may also be faxed to 303-236-4005 or sent by electronic mail to Comments will be accepted until January 14, 2008. 

Oral and written comments will also be accepted at the following scheduled public hearings.  The public hearings will be held from 6:00 p.m. to 8:00 p.m. preceded by an informational open house from 4:00 pm to 5:00 p.m.

December 10, 2007:  U.S. Fish and Wildlife Service Regional Office

                                          134 Union Boulevard

                                          Lakewood, Colorado

December 12, 2007:       First State Bank Conference Center

                                          1405 16th Street

                                          Wheatland, Wyoming

Today’s finding and other materials are available on the Service’s web site at:

The U.S. Fish and Wildlife Service is the principal federal agency responsible for conserving, protecting and enhancing fish, wildlife and plants and their habitats for the continuing benefit of the American people. The Service manages the 97-million-acre National Wildlife Refuge System, which encompasses 548 national wildlife refuges, thousands of small wetlands and other special management areas. It also operates 69 national fish hatcheries, 64 fishery resources offices and 81 ecological services field stations. The agency enforces federal wildlife laws, administers the Endangered Species Act, manages migratory bird populations, restores nationally significant fisheries, conserves and restores wildlife habitat such as wetlands, and helps foreign and Native American tribal governments with their conservation efforts. It also oversees the Federal Assistance program, which distributes hundreds of millions of dollars in excise taxes on fishing and hunting equipment to state fish and wildlife agencies.


- FWS -