The Role of Science in Western Grey Squirrel Enhancement in Oak Woodlands of South Puget Sound

Western gray squirrels are extremely rare, wary, and sensitive to disturbance in the Puget Sound lowlands of western Washington. A pilot project was implemented to test a non-invasive survey technique to determine the current distribution of western and eastern gray squirrels in historic western gray squirrel habitat on the Fort Lewis Military Base for the purpose of guiding and evaluating management actions in Oregon white oak – conifer woodlands. We baited and distributed 130 hair snagging tubes in historic western gray squirrel habitat and monitored them at two – six week intervals for the presence of hairs. Dorsal guard hairs were identified to squirrel species based on their color banding patterns under 30X magnification. A total of 77 tubes yielded 146 hair samples: 45 samples contained western gray squirrel hairs, and 79 contained eastern gray squirrel hairs. Oak – conifer woodlands yielding hairs of western gray squirrels are targeted for foot surveys to monitor changes in relative abundance of squirrels. A data base that integrates distribution and relative abundance data through time is being developed to produce maps to guide, evaluate, and inform management actions. Hair snagging tubes, combined with foot surveys, show promise as a non-invasive approach to providing information on the distribution and relative abundance of a rare and secretive squirrel population to guide and evaluate management actions designed to enhance its population.