Bat species overwintering in lava-tube caves in Lincoln, Gooding, Blaine, Bingham, and Butte counties, Idaho, with special reference to annual return of banded Plecotus townsendii

Publication Type:

Thesis

Authors:

Wackenhut, Martha C.

Source:

Biology, Idaho State University, Pocatello, ID, p.64 (1990)

Call Number:

U90WAC01IDUS

Keywords:

Antrozous pallidus, Corynorhinus townsendii, Lasionycteris noctivagans, Little Brown Myotis, Long-eared Myotis, Myotis evotis, Myotis lucifugus, Myotis yumanensis, pallid bat, Pipistrellus hesperus, Plecotus townsendii, Silver-haired Bat, Townsend's Big-Eared Bat

Abstract:

The objectives of this study were to increase the knowledge of bat species composition and local distribution in south-central and southeastern Idaho, to determine the population status of winter resident bat species, and to document movements of banded bats. Plecotus townsendii [Corynorhinus townsendii] was a summer resident of the Idaho National Engineering Laboratory (INEL) and of the Lincoln–Gooding county study area (LGC). This species also hibernated in lava-tube caves in both areas in numbers ranging from 3 to 406 per cave in the mid-winter. Myotis leibii was a summer resident of the LGC and hibernated in both areas in numbers ranging from 1 to 28 per cave in the mid-winter. Other summer residents of the LGC included Myotis evotis, Myotis lucifugus, Antrozous pallidus, and Pipistrellus hesperus. Lasionycteris noctivagans were found in the late summer, and Myotis yumanensis were found using a cave in early spring as either a hibernaculum or a day roost. Band returns of 514 P. townsendii from 11 caves ranged from 11.1 to 60.9% the year following banding. Movement of individuals of this species during hibernation was limited to adjacent caves and was likely induced by banding disturbance. The longest movement documented was 8.3 km between hibernation periods rather than during a hibernation period. P. townsendii was found hibernating from 0.6 to 11 °C and from 44 to 90% relative humidity. Female P. townsendii lost an average of 3.0 gm (n=43), or 21.9%, of their fall body weight over the winter. Males lost an average of 2.4 gm (n=10), 21.5%, of their fall weight over the winter. Females of this species enter caves to hibernate earlier in the fall than do males. A male:female ratio of 1:3.4 was found in the fall in caves. A male:female ratio of 1:1.2 was found in caves during spring.