Myotis
californicus
(California
Myotis)
Description:
The upper fur is brownish chestnut
and tends to have a yellowish cast. The cranium is not flattened, a condition
found in western small-footed myotis with which this species may be confused.
The ears are rounded at the margin and extend slightly beyond the muzzle. A
brownish area exists across the face to the ears. The tragus
is less than one-fourth of the length of the ear and is pointed. The calcar
is keeled and the foot small.
Range:
The southeastern portion of Alaska and western half of British Columbia
south through Idaho and Utah, along the western edge of Colorado, New Mexico,
into central Mexico, west into Baja California and throughout the Pacific states
of California, Oregon and Washington. In Idaho, this species has been collected
in three counties.
From extreme southern Alaska and western Canada, south in lowlands through Montana, Utah, and California, and throughout desert Southwest. Winters in California, Nevada, Utah, Arizona, and Texas. Full extent of winter range is not known. In Idaho, species has only been observed near west-central border, but distribution is probably more widespread.
Habitat:
This bat has been found in western
and panhandle counties in Idaho, in a variety of habitats from forest to desert
conditions. It appears to be more common in areas with open areas of slack water.
Summer roosts include crevices in rocky hillsides, rocky outcrops, buildings,
trees with exfoliating bark, and cavities in snags.
Found from seacoasts to deserts, at elevations
up to about 1800 m, in oak/juniper situations, canyons, riparian
woodlands, desert scrub,
and grasslands.
Diet:
California myotis eat
small insects including moths, beetles, and flies. The food taken may vary with
the diet of similar-sized sympatric species if present, especially Western small-footed
myotis. Insectivorous .
Ecology:
Periods of foraging activity may vary
with temperature in this species and flight may occur during freezing conditions.
Colonies appears to be small. Mine use may be limited, but the roosting requirements
of this species needs further study.
Known to hibernate
in U.S. during winter,
but winter activity has also been recorded. In southern California, occasional
individuals have been found active on warm winter days. Active bats have been
regularly caught in Nevada in fall and winter (frequently in temperatures below
43° F). Species hibernates in caves, mines, tunnels, or buildings. Forages with
slow, erratic flight pattern approximately 1.5-3 m off ground. Often uses human-built
structures for night roosts
. Uses crevices of various
kinds for summer day roosts.
Reproduction:
Mating takes place during the fall,
excepting California where it may occur during the spring. A single pup is born.
Nursery colonies are small, the largest found in Canada consisted of 52 individuals.
Very little is known about this species in Idaho.
Ovulation and fertilization
are delayed until spring.
Female gives birth to 1 young in late May to mid-June, depending on range (July
in Canada). Nursery colonies are usually small (up to about 25 individuals).
Conservation:
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Global Rank: | G5 |
State Rank: | S1 |
Important State References:
Keller, B.L. 1987. Analysis of the
bat species present in Idaho, with special attention to the spotted bat, Euderma
maculatum. Dept. Biol. Sciences, Idaho St. Univ., Pocatello. 25pp.