170 
PROCEEDINGS OF THE CALIFORNIA ACADEMY OF SCIENCES 
Series 4, Volume 65, Supplement I 
ment (2017a,b): Species of 
Greatest Conservation Need, Tier 
III. 
Description. — The long- 
legged myotis (Fig. 35) is an 
intermediate-sized myotis, with 
forearm lengths of about 35 to 42 
millimeters, body mass ranging 5 
to 10 grams, small ears, and a 
keeled calcar; fur on the under¬ 
side of the wing extends to the 
level of the elbow, and is more 
dense than in little brown (M 
lucifugus ) or Arizona myotis, 
which lack a keeled calcar (for 
example, Hoffmeister 1986; 
Czaplewski, 1999; Armstrong et 
al., 2011; Ammerman et al., 2012a). Considerable color variation in the pelage can be found among 
individuals within a given locality (for example, Allen, 1919; Benson, 1949; Vaughan, 1954). 
Distribution and Systematics. — The long-legged myotis is found in western North Amer¬ 
ica from southeastern Alaska to central Mexico (Fig. 36). The name Myotis volans has been 
assigned to this species for over a hundred years (Goldman, 1914). There are four recognized sub¬ 
species (Simmons, 2005): M. volans volans (Baja California, Mexico), M. volans amotus (found at 
lower altitudes and deserts in Mexico), M. volans interior (the interior western U.S. and Canada), 
and M. volans longicrus (the Pacific Northwest and Canada). Warner and Czaplewski (1984) pro¬ 
vided further details and original references on subspecies and a synonymy of past scientific names 
applied to the long-legged myotis. Molecular genetic variation within the species and relationships 
with other species of Myotis are discussed by Dewey (2006). Other English common names that 
appear in the literature include hairy-winged myotis, long-legged bat, interior bat, and western lit¬ 
tle brown bat. 
Habitats and Relative Abundance. — Long-legged myotis are found in a variety of west¬ 
ern forest types and scrublands, where at many sites they often are among the species most fre¬ 
quently captured in mist nets. They are found over a wide range of elevations from near sea level 
(Benson, 1949) to high mountain habitats. They are among the few species of western bats found 
at high elevations, taken at 3,352 meters in the Sierra Nevada of California (Allen, 1919) and 3,500 
meters in Colorado (Armstrong et al., 1994), where a carcass was recently recovered at 4,307 
meters (Armstrong et al., 2011). 
Pacific Northwest, Northern Rocky Mountains, and Alaska: Oregon, Washington, and 
British Columbia: Long-legged myotis were reported to be the most frequently captured species 
of bat across several forest types in northeastern Oregon (Whitaker et al., 1981). This was the sec¬ 
ond most abundant (179 captured among 412 individuals) out of eight species of night-roosting 
bats captured at five bridges in western hemlock ( Tsuga heterophylla) forest in the Willamette 
National Forest of Oregon (Perimeter, 1996). They were of lower relative abundance in surveys 
over streams and ponds in Douglas fir ( Pseudotsuga menziesii)-wQStcrn hemlock forests across the 
western Cascades in southern Washington and the Oregon Coast Range, ranking fifth among 12 
species (nine bats out of 241 individuals; Thomas, 1988). In the same study, echolocation activity 
of this species was greater in old growth stands than in mature or younger stands, with feeding rates 
Figure 35. Long-legged myotis, Myotis volans (photo by J. Scott Alten- 
bach). 
