| Popis: |
Limited information exists on the ecology and habitat requirements of the pallid bat (Antrozous pallidus) inhabiting forested ecosystems at the northern limits of its range. We used mist netting, radiotelemetry, and emergence counts at roosts to identify foraging and roosting habitat of pallid bats on the Plumas National Forest in northern California during summer 2007. Pallid bats used a variety of structures for day and night roosting, including live trees and snags, a rock crevice, and a building. Live trees and snags used for roosting were consistently tall in height, large in diameter, and located in mature stands in micro-sites with low percentages of overstory and mid-story cover. The height of roosting sites used by pallid bats in live trees and snags was low relative to the height of the stems selected for roosting. Size of foraging areas varied among sex and reproductive classes of pallid bats, with lactating females (1.56 km2 ± 0.88 SE) exhibiting the smallest foraging areas and post-lactating females (5.97 km2 ± 2.69 SE) having the largest foraging areas. Sierran mixed conifer and white fir habitats comprised significantly larger proportions of the available habitat within foraging areas of adult females than other habitats. Long distance movements during nightly foraging, > 2 km, were common for all sex and reproductive classes of pallid bats. These data indicate that pallid bats inhabiting coniferous forests choose alternate habitats in which to forage and roost from those typically used by the species in other regions of its distribution. |
