The Western Small-footed Myotis is the smallest bat in British Columbia. Its fur colour varies from pale tan to orange-yellow on the back; the underside is paler, almost buff. The black ears, wing and tail membranes, face and snout contrast strikingly with the pale fur. The length of the naked area on the snout is about one and a half times the width across the nostrils. The ears are relatively long; the tragus is long and narrow. There is a distinct keel on the calcar; the foot is small. The skull is very small and delicate with a gradually sloping forehead.
IdentificationThis species is smaller than the Fringed Myotis (Myotis thysanodes) and the Long-legged Myotis (Myotis volans). Its small foot and presence of a prominent keel on the calcar distinguishes it from the Western Long-eared Myotis (Myotis evotis), Little Brown Myotis (Myotis lucifugus) and Yuma Myotis (Myotis yumanensis). The California Myotis (Myotis californicus) is similar in size and possesses a keeled calcar; see that species account for distinguishing traits.
Dental Formulaincisors: 2/3
Measurementstotal length: 83 (72-90) n = 44
tail vertebrae: 38 (32-45) n = 44
hind foot: 7 (6-8) n = 44
ear: 13 (8-15) n=25
tragus: 7 (4-9) n = 24
forearm: 31.8 (28.8-33.4) n = 47
wingspan: 221 (205-245) n = 25
weight: 4.6 (2.8-5.5) n = 23