Bat Inventory in Olympic National Park

West, Stephen; Adam, Patrick; Bickford, Elizabeth; Noe, Michelle

The diverse environmental gradients on the Olympic peninsula present many interesting research questions for bats. The east side of the peninsula is far drier than the unprotected west side and may provide habitats more amenable to bats due to a presumed greater activity of nocturnal flying insects. Differences in humidity and temperature with changes in elevation may also influence bat presence and activity as a function of insect activity. Different forest types, such as Sitka spruce and Western hemlock/Douglas-fir may also show differences in bat species composition. While the primary goal for the bat survey was to verify bat species presence in the Park, we documented occurrence in a systematic way that provided additional insight into the patterns of bat species occurrence on the Olympic Peninsula. We expected that the strong environmental gradients of the peninsula would affect not only bat species presence, but also their population structure and reproductive biology. As we collected information on bat species presence we investigated the influence of elevation, precipitation, and selected vegetation types on bat distribution.