Myotis californicus 


Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Mammalia Chiroptera Vespertilionidae

Scientific Name: Myotis californicus
Species Authority: (Audubon & Bachman, 1842)
Common Name(s):
English California Myotis, Californian Myotis

Assessment Information [top]

Red List Category & Criteria: Least Concern ver 3.1
Year Published: 2008
Date Assessed: 2008-06-30
Assessor(s): Arroyo-Cabrales, J. & Perez, S.
Reviewer(s): Medellín, R. (Chiroptera Red List Authority) & Schipper, J. (Global Mammal Assessment Team)
This species is listed as Least Concern in because of its wide distribution, presumed large population, occurrence in protected areas, tolerance to some degree of habitat modification, and because it is unlikely to be declining at nearly the rate required to qualify for listing in a threatened category.
Previously published Red List assessments:
1996 Lower Risk/least concern (LR/lc)

Geographic Range [top]

Range Description: S Alaska Panhandle (USA) to Baja California and higher elevations in the Sonoran and Chihuahuan deserts (Mexico); Guatemala (Simmons 2005).
Countries occurrence:
Canada (British Columbia); Guatemala; Mexico; United States (Alaska, Arizona, California, Colorado, Idaho, Montana, Nevada, New Mexico, Oregon, Texas, Utah, Washington)
Range Map: Click here to open the map viewer and explore range.

Population [top]

Population: California bats roost alone or in small groups during the warmer months. They can be found in caves, mines, rocky hillsides, under tree bark, on shrubs, on the ground, and in buildings. Males and females roost separately during the warmer months. Females form small maternity colonies during pregnancy, birth, and lactation. During the winter months the sexes mingle and roost either solitarily or in small groups in caves, mines, and buildings. At high elevations and latitudes, they have been reported to hibernate in mines and caves during winter months, though they have been observed to be active for short time periods at temperatures below freezing, indicating that they occasionally emerge from torpor to feed. In forest populations, considerable switching of roosts has been documented, and a roost will seldom be re-used by the same bat once it has changed to a new one.
Current Population Trend: Unknown
Additional data:
Population severely fragmented: No

Habitat and Ecology [top]

Habitat and Ecology: 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). There is little documented information available on reproduction and ontongeny in M. californicus. It is known that mating occurs in autumn. 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). 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).
Found in roofs in Guatemala (Sergio Perez pers. comm.)
Systems: Terrestrial

Threats [top]

Major Threat(s): There are no major threats throughout the species' range.

Conservation Actions [top]

Conservation Actions: Found in protected ares in Mexico, but not in Guatemala.

Classifications [top]

1. Forest -> 1.4. Forest - Temperate
suitability: Suitable  
1. Forest -> 1.5. Forest - Subtropical/Tropical Dry
suitability: Suitable  
1. Forest -> 1.9. Forest - Subtropical/Tropical Moist Montane
suitability: Suitable  
7. Caves and Subterranean Habitats (non-aquatic) -> 7.1. Caves and Subterranean Habitats (non-aquatic) - Caves
suitability: Suitable  
8. Desert -> 8.2. Desert - Temperate
suitability: Suitable  
14. Artificial/Terrestrial -> 14.5. Artificial/Terrestrial - Urban Areas
suitability: Marginal  
1. Land/water protection -> 1.1. Site/area protection
2. Land/water management -> 2.1. Site/area management

In-Place Research, Monitoring and Planning
In-Place Land/Water Protection and Management
In-Place Species Management
In-Place Education

Bibliography [top]

Banfield, A. W. F. 1974. The Mammals of Canada. University of Toronto Press.

Fenton, M. and Bell, G. 1979. Echolocation and feeding behaviour in four species of Myotis (Chiroptera). Canadian Journal of Zoology 57: 1271-1277.

IUCN. 2008. 2008 IUCN Red List of Threatened Species. Available at: (Accessed: 5 October 2008).

Nagorsen, D. and Brigham, M. 1993. Royal British Columbia Museum Handbook: Bats of British Columbia. University of British Columbia Press, Vancouver, Canada.

Simmons, N.B. 2005. Order Chiroptera. In: D.E. Wilson and D.M. Reeder (eds), Mammal Species of the World, pp. 312-529. The Johns Hopkins University Press, Baltimore, MD, USA.

Simpson, M. 1993. Myotis californicus. Mammalian Species 428: 1-4.

Wilson, D.E. and Ruff, S. 1999. The Smithsonian Book of North American Mammals. Smithsonian Institution Press, Washington, DC, USA.

Citation: Arroyo-Cabrales, J. & Perez, S. 2008. Myotis californicus. The IUCN Red List of Threatened Species 2008: e.T14150A4410193. . Downloaded on 25 November 2015.
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