Published: August 2020
Author(s): Derek W. Stinson
The Mazama Pocket Gopher (Thomomys mazama), a small fossorial rodent, is a regional endemic found only in western Washington, western Oregon, and northern California. Pocket gophers play an important role in ecological communities by altering soil structure and chemistry, affecting plant occurrences, serving as prey for many predators, and providing burrows that are used by a wide variety of other species. Mazama Pocket Gophers were formerly more widespread on south Puget Sound prairies, but their distribution has diminished due to habitat loss and degradation. Protecting or restoring prairie sites for gophers will also help conserve other prairie associated species. The species was state-listed as threatened by the Washington Fish and Wildlife Commission in 2006.
This document is the state recovery plan and first periodic status review for the Mazama Pocket Gopher; it is intended to provide a status update and guide conservation and recovery efforts. It identifies a recovery goal, specifies population targets for reclassification, and outlines recovery strategies and tasks. It also provides an update on the species’ status since the 2005 status report and the 2013 draft recovery plan, based on recent research and monitoring information relevant to Mazama Pocket Gophers in Washington.
In 2001, the U.S. Fish and Wildlife Service (USFWS) designated eight subspecies of the Mazama Pocket Gopher in Washington as candidates for listing under the federal Endangered Species Act. In 2014, the USFWS added four of these subspecies (T. m. pugetensis, tumuli, yelmensis, and glacialis) to the federal list of Threatened species and designated critical habitat. The USFWS also promulgated a special 4(d) rule that exempts some activities from the Act’s Section 9 take prohibitions, including some existing maintenance activities at airports and farms, livestock grazing, some agricultural activities, and certain activities on single-family residential properties (USFWS 2014a,b).
The Mazama Pocket Gopher is primarily found in areas with well-drained glacial outwash soils and herbaceous vegetation, many of which were historically prairies and savannahs. The species also occasionally inhabits areas with loamy sand or gravelly soils when the tree cover is removed and herbaceous vegetation is established. WDFW conducted extensive Mazama Pocket Gopher surveys in 2012 that included nearly 1,000 survey plots in Thurston, Mason, Pierce, Lewis, Grays Harbor, Wahkiakum, and Clark counties. Between 2014 and 2017, the U. S. Fish and Wildlife Service surveyed over 1,200 sites in response to development permit applications to Thurston County or cities. The results of the surveys generally confirmed previous descriptions of the distribution of Mazama Pocket Gophers in Washington and refined our understanding of gopher occupancy in various soil types.
Much of the historical gopher habitat of south Puget Sound with appropriate soils and vegetation has been degraded by Scotch Broom (Cytisus scoparius), fragmented, or converted to impervious surfaces. Habitat loss to forest succession, agriculture and development has eliminated most of the prairie vegetation. Although significant areas remain in grassland, pasture, or turf, trends in the human population suggest that available habitat and the quality of habitat will continue to decline without careful management of conflicting uses. The human population in Washington is expected to increase from the current 7.5 million to 9.2 million by 2040. As the habitat patches become smaller, fewer, and farther apart, the likelihood of each patch continuing to support pocket gophers declines.
Recovery. The goal of the recovery plan is to secure and maintain self-sustaining representative populations of all the distinct genetic groups of the Mazama Pocket Gophers within the current Washington range. Seven areas that have substantial portions of the remaining habitat and contain populations of Mazama Pocket Gophers in Thurston, Pierce, and Mason counties are identified for recovery emphasis.
Conservation of the populations in seven areas (five in Thurston County, one in Pierce County, and one in Mason County) would preserve representative local populations across their range in the south Puget Sound region. Some portions of the range that are densely developed but still host small numbers of gophers in scattered remnants of open habitat (e.g. road margins, etc.), were not identified for recovery emphasis because the potential for long-term persistence is assumed to be low.
Recommendation and recovery objectives. The Mazama Pocket Gopher should remain listed as threatened, but should be considered for downlisting to Sensitive status when the following objectives have been met:
- Two reserves or reserve complexes are established in each of the Bush Prairie, Mound-Frost Prairie, and 91st Division Prairie recovery areas, and one reserve each in Rocky Prairie, Tenalquot-Yelm Prairie, Chambers Prairie, and Scotts Prairie recovery areas;
- Each of the reserves/reserve complexes in at least five of seven reserve areas, supports a population of ≥1,000 Mazama Pocket Gophers.
Conservation activities will focus on protecting and maintaining habitat, and maintaining or restoring habitat connectivity in reserve complexes. Much of the occupied gopher habitat in the south Puget Sound region is in public ownership, but some has uses that can conflict with the needs of gophers and a number of sites are on private lands. Recovery will involve partnerships with landowners, federal, state, and local agencies, and private conservation organizations. Incentive programs and partnerships are recommended to facilitate the maintenance of functional pocket gopher habitat in rural residential and agricultural areas with the help of private landowners.
Recovery objectives may be revised if the best available science indicates changes are needed. The species’ population and listing status will be reviewed every five years as recovery progresses.
Stinson, D. W.. 2020. Mazama Pocket Gopher Recovery Plan and Periodic Status Review. Washington Department of Fish and Wildlife, Olympia.102+vii pp.
Draft documents are provided for informational purposes only. Drafts may contain factual inaccuracies and may not reflect current WDFW policy.