Oregon’s dusky tree vole under study as possible endangered species

By US Fish and Wildlife Service,

The U.S. Fish and Wildlife Service announced today it will begin a year-long study to determine whether the dusky tree vole, a small tree-dwelling rodent that occurs in the north Coast Range in Oregon, qualifies for protection under the federal Endangered Species Act.

The status review will seek to determine whether the dusky tree vole qualifies as a subspecies of the red tree vole and if so, whether it requires protection. As appropriate, the status review will also evaluate the north Oregon coast population of red tree vole and the red tree vole throughout its range.  For the next 60 days the Service is seeking information that will help the agency make these determinations. Public comments must be received by December 29, 2008.

“Very little is known about the dusky tree vole as compared to other Pacific Northwest forest species,” said Dave Wesley, Acting Director of the Service?s Pacific Region. “There is conflicting evidence regarding whether the dusky is a subspecies of the red tree vole, which bears on whether it can be separately listed under the ESA.”

The Center for Biological Diversity, four other organizations and two private citizens petitioned the Service on June 22, 2007, seeking protection under the ESA for the dusky tree vole.  The petitioners requested that if the dusky tree vole was not found to be a subspecies the agency instead should list the north Oregon coast population of the red tree vole as a Distinct Population Segment or list the red tree vole throughout all of its range because the species is threatened or endangered in a significant portion of its range.

The Endangered Species Act states that only a species, a subspecies, or a distinct population segment may be listed as threatened or endangered. Agency regulations define how a distinct population segment can qualify for listing, using such factors as the population segment’s discreteness and significance to the rest of the species.

According to the petitioners, the dusky tree vole is at risk because of habitat loss due to logging and other habitat-removing disturbances.  Tree voles have low mobility and poor dispersal capability, making them unable to respond to loss of forest habitat.

During the public comment period, the Service is seeking information on the dusky tree vole, and the red tree vole as it relates to the dusky tree vole, concerning:

Information on historical and current distribution and the effects of past habitat management on that distribution; Information related to population abundance, dynamics and trends; Information on the genetic, morphological, behavioral and other characteristics of dusky and red tree voles;
Information relevant to whether any population of red tree vole in western Oregon may qualify as a distinct population segment.
In addition, the Service is requesting information clarifying the range of the three possible listable entities described by the petitioner: the dusky tree vole; the north Oregon coast population of the red tree vole; and the entire range of the red tree vole because threats exist in a significant portion of its range.

Finally, the Service is seeking information relative to all five threat factors the ESA uses to determine if a species is threatened or endangered:

Present or threatened destruction, modification or curtailment of its habitat or range;
Overutilization for commercial, recreational, scientific or educational purposes;
Disease or predation;
The inadequacy of existing regulatory mechanisms;
Other natural or manmade factors affecting its continued existence.
Red and dusky tree voles are rodents that are a little smaller than an average common house mouse – weighing only about three to five ounces. They are found only along the Oregon Coast and in the Western Cascades of Oregon. Their coat is thick, soft and long, ranging in color from brownish red on the back to bright brownish-red or orange-red. Active at night, they spend their lives in the tops of tall Douglas-fir or other conifers, building nests up to bushel-basket size and eating the conifer needles. They get water from rain drops and condensation that collects on the conifer needles. Little is known about their ability to move among isolated islands of habitat.

Information and comments must be received by December 29, 2008, via one of the following methods:

Federal Rulemaking Portal: http://www.regulations.gov. Follow the instructions for submitting comments.
U.S. mail or hand-delivery: Public Comments Processing, Attn: RIN 1018-AV00; Division of Policy and Directives Management; U.S. Fish and Wildlife Service; 4401 N. Fairfax Drive, Suite 222; Arlington, VA 22203.
The mission of the U.S. Fish and Wildlife Service is working with others to conserve, protect and enhance fish, wildlife, plants and their habitats for the continuing benefit of the American people. We are both a leader and trusted partner in fish and wildlife conservation, known for our scientific excellence, stewardship of lands and natural resources, dedicated professionals and commitment to public service. For more information on our work and the people who make it happen, visit www.fws.gov.

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