The California Myotis is one of our smallest species. Its fur colour varies from rusty to blackish brown and is dull, lacking a glossy sheen. Its ears and its wing and tail membranes are black. The ears extend beyond the nose when pushed forward; the tragus is long and narrow. The length of the naked area on the snout is roughly equal to the width across the nostrils. The hind foot is small; the calcar has a prominent keel. The small, delicate skull has a steeply sloping forehead.
IdentificationIn south-central British Columbia, the California Myotis can be confused with the Western Small-footed Myotis (Myotis ciliolabrum), but the latter has paler fur that contrasts more sharply with the black wings, face and ears, and it has a longer bare area on its snout. In other parts of the province the small size (forearm less than 36 mm), small foot and keeled calcar will readily distinguish the California Myotis from other Myotis species. The small skull (less than 3.4 mm postorbital width) separates this bat from all other species of Myotis except the Western Small-footed Myotis. The skull of the California Myotis has a more steeply sloped forehead than the skull of the Western Small-footed Myotis.
Dental Formulaincisors: 2/3
Measurementstotal length: 80 (65-95) n = 75
tail vertebrae: 36 (26-41) n = 77
hind foot: 6 (5-9) n = 80
ear: 13 (8-15) n = 40
tragus: 4 (4-8) n = 35
forearm: 32.1 (29.4-35.0) n = 68
wingspan: 222 (209-251) n = 28
weight: 4.4 (3.3-5.4) n = 26