40 
PROCEEDINGS OF THE CALIFORNIA ACADEMY OF SCIENCES 
Series 4, Volume 65, Supplement I 
again since the 1990’s. The literature prior to the early 1960’s is further confounded by the now- 
incorrect application of the name C. rafinesquii (or P. rafinesquii) to C. townsendii, or the desig¬ 
nation of Townsend’s big-eared bat as C. rafinesquii townsendii. Currently, however, C. rafinesquii 
remains the appropriate species name solely for Rafinesque’s big-eared bat in the southeastern U.S. 
These changes reflect continual refinements and progress in understanding the systematic and evo¬ 
lutionary relationships of bats. Genetic analysis using nuclear DNA sequences and mitochondrial 
DNA analysis affirm the relationships among the species of Corynorhinus and the subspecies of 
Townsend’s big-eared bat (Piaggio and Perkins, 2005; Piaggio et al., 2009; Lack and Van Den 
Bussche, 2009; Tipps 2012). See Kunz and Martin (1982) for a taxonomic synonymy of past sci¬ 
entific names applied to Townsend’s big-eared bat prior to the more recent changes noted in the 
above references. 
The generic name Corynorhinus stems from Greek words meaning “club” and “nose”. This bat 
is named in honor of John Kirk Townsend, an American naturalist and collector during the early 
1800’s (not Charles H. Townsend, a later naturalist, as attributed by Kunz and Martin, 1982). Other 
English common names include western lump-nosed bat, western long-eared bat, western big- 
eared bat, western long-nosed bat, long-eared bat, jack-rabbit bat, and mule-eared bat. 
Habitats and Relative Abundance. — In the western U.S., Townsend’s big-eared bats are 
found in a wide variety of habitats, ranging from arid desert lowlands to fir forests (for example, 
Dalquest, 1947a; Easterla, 1973; Findley et al., 1975; Ports and Bradley, 1996; Szewczak et al., 
1998). However, they are usually restricted to areas within these habitats that provide roosts in 
caves, or cave-like structures such as mines, large rock crevices or cavities, and some bridges and 
buildings (see “Roosting Habits” below). This species is often among the least abundant captured 
in mist-netting surveys. Low relative abundance may be a reflection of rarity, but it could be attrib¬ 
utable in part to capture bias if their maneuverability and echolocation abilities allow them to avoid 
nets more readily than other species (for example, Cockrum and Ordway, 1959) and because they 
may not move far from limited roosting habitat. These factors of detectability may negatively bias 
relative abundance data. Positive bias to relative abundance data may also occur when observations 
are based on counts at roosts if this species is more dependent on open and conspicuous (observ¬ 
able) roosting sites within caves and mines where bats are often sought. 
Pacific Northwest and Northern Rocky Mountains: Oregon and Washington: Only one 
Townsend’s big-eared bat was captured in surveys over streams and ponds in Douglas fir-western 
hemlock forests across the western Cascades in southern Washington and the Oregon Coast Range, 
ranking last among 12 species and 241 individuals captured (Thomas, 1988). Similarly, they were 
the least abundant of 11 species collected for stomach contents analysis in eastern Oregon, with one 
bat taken among a sample of 413 individuals (Whitaker et al., 1981), and they were the least abun¬ 
dant (one capture out of 1,057 individuals of 11 species) among bats captured over water in the pre¬ 
dominantly ponderosa pine forests of the eastern Cascade Mountains of south-central Washington 
(Baker and Lacki, 2004). However, Townsend’s big-eared bats ranked fourth of eight species (five 
captured among 412 individuals) of bats captured night roosting at five bridges in western hemlock 
forest in the Willamette National Forest of Oregon (Perimeter, 1996). 
British Columbia: One Townsend’s big-eared bat was captured over water in the semi-arid 
Okanagan Valley of southern British Columbia, where the species ranked as least abundant of 12 
species documented through capture of 958 individuals (Woodsworth, 1981). None were captured 
in the same region during an earlier study where 351 bats of nine species were taken in nets or traps 
over or near water, although one was captured at a talus slope away from water (Fenton et al., 
1980). 
Idaho and Montana : None were documented among 187 bats of eight species captured in mist 
