Forest bat communities in the East Cascade Range, Washington

Publication Type:

Journal Article

Authors:

Baker, Michael D.; Lacki, Michael J.

Source:

Northwest Science, Northwest Scientific Association, Volume 78, Issue 3, p.234-241 (2004)

Call Number:

A04BAK01IDUS

Abstract:

Limited data are available on the occurrence and relative abundance of bat species in Washington. We surveyed forest bat communities on the eastern slope of the Cascade Range in south-central Washington from May through August, 2001 and 2002.We selected two watersheds that differed in range of elevation (760-1260 m vs. 1000-1400 m), contained mixed ownership (public and private), and were subject to forest management practices typical of the ponderosa pine forest zone in eastern Washington. We captured 1057 bats of 11 species over 135 nights of sampling (mean = 2.39 ± 0.23 bats net night). Of captures, 65% were adult males, 29% were adult females, and 6% were volant juveniles. Fifteen percent of adult males and 49% of adult females were reproductively active. We first captured pregnant females of myotis species from 3 to 27 June, and reproductive males from 12 July to 4 August. Volant juveniles of myotis species were captured between 25 July and 13 August. We captured more males per female in the high-elevation watershed (3.53) than in the low-elevation watershed (1.58); the proportion of reproductively active females was not different between watersheds. A greater proportion of males were reproductively active in the high-elevation watershed (0.2) than in the low-elevation watershed (0.09). We captured more juveniles and juveniles of more species in the high elevation watershed. Comparison to other studies showed discrepancies in the relative abundance of fringed myotis and long-legged myotis, suggesting that further study of these species is warranted. These data indicate that management of forest bats should begin to place a greater emphasis on conservation across landscapes.