Kidneys of California bats are adapted for water conservation in arid environments. Where this bat occurs in desert regions and arid interior basins, it utilizes small waterholes to obtain needed moisture (Wilson and Ruff 1999).
Perception Channels: tactile ; chemical
The status of the California bat is common (CITES 2000; IUCN Species Survival Commission 2000; USFWS 2000).
Temperate North American bats are now threatened by a fungal disease called “white-nose syndrome.” This disease has devastated eastern North American bat populations at hibernation sites since 2007. The fungus, Geomyces destructans, grows best in cold, humid conditions that are typical of many bat hibernacula. The fungus grows on, and in some cases invades, the bodies of hibernating bats and seems to result in disturbance from hibernation, causing a debilitating loss of important metabolic resources and mass deaths. Mortality rates at some hibernation sites have been as high as 90%. While there are currently no reports of Myotis californicus mortalities as a result of white-nose syndrome, the disease continues to expand its range in North America.
US Federal List: no special status
CITES: no special status
IUCN Red List of Threatened Species: least concern
California bats may cause disturbance by their use of man-made shelters as roosts. In addition, the presence of rabies has been detected in specimens, although not at significant levels (Banfield 1974).
Through its consumption of insects, California bats play an important role in ecological balance and crop pest population control (Banfield 1974).
California bats are insectivorous, feeding mainly on flies, moths and beetles. They forage only on insects in flight and are slow, acrobatic flyers, detecting prey at close range (less than 1 meter) and using echolocation calls during approach. Specific diet remains constant throughout the year, but likely varies from area to area. In British Columbia, M. californicus has been observed feeding mainly on Trichoptera and some Coleoptera, while further south, in Oregon, consumption consists primarily of Lepidoptera and Diptera (Banfield 1974; Fenton and Bell 1979; Simpson 1993; Wilson and Ruff 1999).
The range of California bats extends from southeastern Alaska, through the western United States, south to southern Mexico. In Canada they are confined to British Columbia, including coastal Vancouver Island and Queen Charlotte Islands (Nagorsen and Brigham 1993).
Biogeographic Regions: nearctic (Native )
California bats have a wide tolerance of habitat including semi-arid desert regions of the Southwest, arid grasslands, forested regions of the Pacific Northwest, humid coastal forests and montane forests (Banfield 1974; Nagorsen and Brigham 1993).
Terrestrial Biomes: desert or dune ; forest ; mountains
California bats measure 70-94 mm in total length, with a forearm length of 30-35 mm, making them one of the smallest Myotis species in North America. The fur is long and dull, not glossy, and shows great geographic variation in colour, ranging from rusty reddish-brown to rich-dark chestnut brown. In high-altitude populations of M. californicus a darker pelage prevails. Where it is found in arid areas the fur is typically pale yellowish-orange. In areas of low elevation, the bat is especially small in size and pale in colour, while in the forests of the Pacific Northwest and the forested highlands of Mexico, it is darker in colour. There is no distinct sexual dimorphism in this species, although females are, on average, larger than males in most comparisons. The ears, wings and tail membranes are black. The ears are relatively long and extend beyond the nose when pushed forward. The hind foot is small, less than half the length of the tibia (6-9 mm). The dental formula is 2/3 1/1 3/3 3/3 = 38. The calcar is slender and prominently keeled, and the skull is delicate, characterized by a steeply sloping forehead. Northern individuals have been found to have smaller skull dimensions than those in the south (Banfield 1974; Nagorsen and Brigham 1993; Simpson 1993; Wilson and Ruff 1999).
Range mass: 3.3 to 5.4 g.
Other Physical Features: endothermic ; bilateral symmetry
There is little documented information available on reproduction and ontongeny in M. californicus. It is known that mating occurs in autumn. Females store sperm in the uterus and fertilization follows ovulation in the spring. In California mating also may occur in the spring. A single young is born in late June or early July. The young develop rapidly and can fly about one month after birth. California bats have a potential reproductive lifespan of 15 years (Nagorsen and Brigham 1993; Simpson 1993; Wilson and Ruff 1999).
Range number of offspring: 1 to 1.
Key Reproductive Features: seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; viviparous ; sperm-storing
The California myotis (Myotis californicus) is a species of vesper bat. It is found in British Columbia in Canada, Guatemala, Mexico, and in the western United States, including California.[1]
The California myotis is a small (70–94mm and 3.3–5.4g) bat with pale, dull fur. Ears are of medium (12–15mm) size, with a narrow, pointed tragus (ear). They have an obviously keeled calcar and very small feet (5–7mm), smaller even than the feet of the western small-footed myotis, for which they are easily confused. Other distinguishing features include the slightly lighter face mask and shorter appearance of the California myotis' tail. While their tails are the same length, the small-footed myotis' tail extends 2–3mm after the connecting membrane (Uropatagia) which makes it appear longer.[2]
The dental formula for M. californicus is 2.1.3.33.1.3.3 × 2 = 38[3]
During the day, the California myotis will roost in the bark of dead trees,[4] particularly ponderosa pines,[4][5] rock crevices, or buildings. The California myotis prefers forested areas and is seldom found in urban environments or open rural spaces.[6] They tend to emerge just after dusk and just before dawn to forage. Diet includes moths, flies, and other flying insects.[7] Their flight is slow and highly maneuverable, which assists in prey capture.[2]
California myotis mate in the fall and give birth during the late spring (May - early June). Females give birth to one pup per year and can live for about 15 years in the wild. During the birthing season they form small maternity colonies of about 20 individuals, usually in the loose bark of trees or rock crevices. Males and non-reproductive females roost in small groups or alone.[5] During the winter they may hibernate in mines or rock caves, or they may remain active all winter.
The California myotis (Myotis californicus) is a species of vesper bat. It is found in British Columbia in Canada, Guatemala, Mexico, and in the western United States, including California.
