Use of the forest canopy by bats.

Abstract

Of the 15 species of bats in the Pacific Northwest, 11 are known to make regular use of the forest canopy for roosting, foraging, and reproduction. This paper reviews roosting requirements, foraging, and the importance of landscape-scale factors to canopy using species in the Northwest. Many northwest bats use several different types of tree roosts. Common roosting sites are in cavities, crevices, and foliage. Factors that may be important in roost site selection include microclimate, roost structure, crown architecture, canopy tree age and species, bark characteristics, foliage density, and stand and landscape composition. Some representative Pacific Northwest cavity- and crevice/bark-roosting species include the little brown bat (Myotis lucifugus), silver-haired bat (Lasionycteris noctivagans), and long-legged bat (M. volans). Only two Pacific Northwest species are known to roost in foliage. Several species forage in forest gaps, along forest edges, or in riparian areas. Long-eared (M. evotis) and Keen's (M. keenii) bats may forage within the forest canopy, although foraging behavior of these species in the Pacific Northwest is not well documented. Stand- and landscape-scale complexity may be important in providing bats with the abundance and diversity of roost, foraging, and hibernation sites they require.

Citation

Wunder, L.; Carey, A.B. 1994. Use of the forest canopy by bats. Northwest Science. 68(2): 159