Mammals of California



Common Name

Species Name



Mammal Image Library #s

Mammalian Species #

IUCN Status





CA Notes

CA Citations

Rodentia Muridae Long-tailed Vole Microtus longicaudus Data Deficient as M. l. bernardinus, M. l. coronarius, and M. l. leucophaeus, otherwise Lower Risk Rocky Mountains and adjacent foothills, from E Alaska and N Yukon, south through British Columbia and SW Alberta, Canada, to E California and W Colorado; including Pacific coastal taiga to N California; disjunct southern pockets in S California, Arizona, and New Mexico 1157 271         Usually does not make runways and leaves little sign of its presence. Eats green plant material, seeds, fruit, fungi and bark. Habitat is forests, brushy areas, clear-cuts and sagebrush; often found along rivers or streams.    
Rodentia Muridae Montane Vole Microtus montanus Data Deficient as M. m. codiensis and M. m. zygomaticus, Vulnerable as M. m. fucosus and M. m. nevadensis, Lower Risk (nt) as M. m. arizonensis and M. m. rivularis, otherwise Lower Risk (lc) Cascade, Sierra Nevada and Rocky Mountain ranges: SC British Columbia, Canada, south to EC California, S Utah and NC New Mexico; disjunct populations in S Nevada, EC Arizona and WC New Mexico   716         Mainly diurnal. Makes surface runways through grass but may not use runways in other types of vegetation. Habitat is damp grassland, often near streams or marshes, sometimes in low brush or dense woodlands.    
Rodentia Muridae Creeping Vole Microtus oregoni Lower Risk Moist coniferous forest seres of Pacific Northwest, from SW British Columbia, Canada, south to NW California   233         Makes tiny tunnels among grass roots and sometimes uses underground burrows. Feeds on green vegetation and fungi. Lives in forested and open areas; favors grassy clearings in forests.    
Rodentia Muridae Townsend's Vole Microtus townsendii Lower Risk (cd) as M. t. cowani, otherwise Lower Risk (nt) Wet meadows and marshes of Pacific Northwest, from extreme SW British Columbia, Canada, to NW California, USA, including Vancouver and neighboring islands   325         Active by day or night; swims well and can occupy seasonally flooded areas. Eats grass, clover and rushes. Habitat is wet fields, marshes, stream banks and other areas with dense grass; seldom found in forests.    
Rodentia Muridae White-throated Woodrat Neotoma albigula Endangered as N. varia, Lower Risk as N. albigula SW Colorado and W New Mexico west of the Rio Grande to SE California, south to N Sinaloa and S Chihuahua west of the Rio Conchos, Mexico, including the islands in the Sea of Cortez   310         Mainly nocturnal, but sometimes seen loitering near its house by day in overcast weather. Eats mostly cacti; usually builds a large house under a prickly pear cactus, yucca or cholla, but may den in a rock crevice. Habitat is low to high deserts with abundant succulents, also piñon-juniper zone; favors moderately rocky slopes.    
Rodentia Muridae Bushy-tailed Woodrat Neotoma cinerea Lower Risk SE Yukon and westernmost Northwest Territories, south through Alaskan Panhandle, British Columbia and W Alberta, Canada; in W USA, from Washington to W Dakotas as far south as EC California, S Nevada, N Arizona, and NW New Mexico 1166, 1351 564         Adapted for cool climates, using its busy tail as a wrap in cold weather; cannot survive high temperatures. Seldom constructs an elaborate house, but will accumulate mounds of sticks and other rubbish around the nest site. Lives on rocky outcrops, talus slopes, caves and cliffs, in canyons and mountainous areas.    
Rodentia Muridae Dusky-footed Woodrat Neotoma fuscipes U.S. ESA - Endangered as N. f. riparia; IUCN - Critically Endangered as N. f. riparia, Data Deficient as N. f. annectens, otherwise Lower Risk (lc) Coastal and Cascade mountains, W Oregon, southwards to Inner Coastal Range, WC California and N Sierra Nevadas, EC California   386         Makes large houses, about 3 ft high, 3-7 ft wide, usually placed on the ground around the trunks of trees or in dense brush. Generations of these woodrats use the same house, increasing the size. Lives in dense chaparral, mixed deciduous forest with thick understory, coniferous forest, and coastal sage scrub.    
Rodentia Muridae Desert Woodrat Neotoma lepida Data Deficient as N. l. intermedia, otherwise Lower Risk SE Oregon to C Utah and WC Colorado, south through Nevada, NW Arizona, and S California to S Baja California Sur, Mexico 1252 699         Obtains water from fleshy plants such as yucca and prickly pear cactus. It usually makes a stick house under one of the food plants, or may den among rocks. Lives in deserts and coastal sage scrub; favors areas with rocky outcrops and plentiful succulents.    
Rodentia Muridae Common Muskrat Ondatra zibethicus Data Deficient as O. z. ripensis, otherwise Lower Risk (lc) North America, north to the tree line, including Newfoundland; south to the Gulf of Mexico, Rio Grande and lower Colorado River valleys. Introduced to Czech Republic in 1905 and now widespread in the Palearctic, including C and N Europe, most of Ukraine, Russia and Siberia, adjacent parts of Mongolia and scattered through China, NE Korea, and Honshu Island, Japan; also into southernmost Argentina 1162, 1163 141         Mainly nocturnal, but also active on overcast or rainy days; more likely to be seen by day than other large semiaquatic rodents. Swims well and is more buoyant than a beaver. Habitat is shallow marshes with abundant cattails; less common along streams or in wooded swamps.    
Rodentia Muridae Northern Grasshopper Mouse Onychomys leucogaster Data Deficient as O. l. durranti, otherwise Lower Risk (lc) S Alberta, S Saskatchewan, and SW Manitoba, Canada, south through much of Great Plains and Great Basin region of USA, to NC Sonora and N Tamaulipas, Mexico 253, 1017, 1169 87         Nocturnal; most active on dark moonless nights. Much more carnivorous than most mice, taking large scorpions and beetles and some small vertebrates; also eats seeds and plant material. Mostly very solitary. Habitat is deserts, grasslands, prairies and shrub steppe; favors areas with rather sparse vegetation and sandy soils.    
Rodentia Muridae Southern Grasshopper Mouse Onychomys torridus Data Deficient as O. t. ramona and O. t. tularensis, otherwise Lower Risk (lc) C California, S Nevada, and extreme SW Utah, south to N Baja California Norte, Sonora and N Sinaloa, Mexico 1170 59         Habits similar to Northern Grasshopper Mouse. Nocturnal; travels across open desert floor when hunting and requires sand patches for dust-bathing. Habitat is low desert with scattered shrubs such as creosote bush and mesquite.    
Rodentia Muridae White-footed Vole Arborimus albipes Data Deficient Pacific coastal zone south of Columbia River, from W Oregon to extreme NW California             Apparently nocturnal and semi-arboreal, can climb to canopy height. Feeds on leaves of trees, shrubs and forbs; also eats hazel catkins and small amounts of fungi and insects. Habitat is forests; favors riparian woodland with high densities of alder and hazel or salmonberry.    
Rodentia Muridae Sonoma Tree Vole Arborimus pomo Data Deficient Coastal coniferous forests of NW California, South of Klamath Mountains as far as Sonoma Co.   593         Similar to Red Tree Vole. When disturbed in the nest, may plummet to the ground from heights of up to 60 ft, then race off to hide. Habitat is coniferous forest, mostly with Douglas fir.    
Rodentia Muridae Western Red-backed Vole Clethrionomys californicus Lower Risk as Clethrionomys californicus Coastal coniferous forest from the Columbia River south through W Oregon to NW California   406         Active at any time in Coast Range, thought to be diurnal in Cascades. Travels under logs or under leaf litter. Does not climb. Habitat is moist forest with numerous fallen logs; prefers old-growth coniferous forest with a closed canopy and little undergrowth.    
Rodentia Muridae Sagebrush Vole Lemmiscus curtatus Lower Risk Sagebrush steppe and desert from S Alberta and SE Saskatchewan, Canada, south to EC California and NW Colorado, including the Columbia Basin of interior Oregon and Washington 947, 1339           Mainly crepuscular, but can be active at any time. Lives colonially in a shared burrow system, usually built under cover with multiple entrances. Habitat is dry areas with sagebrush or rabbitbrush, on stony soil.    
Rodentia Muridae California Vole Microtus californicus U.S. ESA - Endangered; IUCN - Vulnerable as M. c. mohavensis and M. c. scirpensis, Data Deficient as M. c. stephensi, Lower Risk (nt) as M. c. vallicola, otherwise Lower Risk (lc) Oak woodlands and grasslands of Pacific coast, from SW Oregon through California, to N Baja California Norte, Mexico   868         Mainly diurnal; most active in the early morning. Eats green vegetation when available; roots and seeds during dry summer months. Makes a nest of shredded grass in the burrow or under a log. Habitat is grassy fields, meadows, marshes, coastal wetlands and recent clear-cuts.    
Rodentia Muridae Brush Deermouse Peromyscus boylii Lower Risk Much of SW USA, from N California to westernmost Oklahoma, south to N Baja California Norta and Trans-Pecos Texas, along the Sierra Madre Occidental and W Central Plateau to Queretaro and W Hidalgo, Mexico 1171 838         Climbs well, but usually nests in rock crevices or under fallen trees. Probably does not dig its own burrows and requires rocks or other ground cover for shelter. Lives in woods and dense brush with rocks, fallen trees, or brush piles; usually found above 3,000 ft to about 8,500 ft.    
Rodentia Muridae California Deermouse Peromyscus californicus Lower Risk C and S California, excluding San Joaquin Valley, to NW Baja California Norte, Mexico   85         Climbs well, but usually encountered on the ground. Unlike most small mammals, forms stable monogamous pairs and lives in small family groups. Habitat is chaparral, oak woods, coastal sage scrub, redwood forests and brushy hills.    
Rodentia Muridae Canyon Deermouse Peromyscus crinitus Lower Risk E Oregon and SW Idaho, south through Nevada and parts of Utah and W Colorado, to EC Baja California Norte and NW Sonora, Mexico   287         Climbs with agility on vertical rock faces or overhanging walls. Does not need to drink water; obtains moisture from food. Lives in desolate rocky terrain with very sparse vegetation, on canyon walls, mesas and talus slopes; below sea level to over 10,000 ft.    
Rodentia Muridae Cactus Deermouse Peromyscus eremicus Lower Risk SE California, S Nevada, and SW Utah east to Trans-Pecos Texas; south along mainland coast to C Sinaloa and on the Mexican Plateau to N Zacatecas and S San Luis Potosi, Mexico 1173 118         Mainly terrestrial, but may climb in low vegetation. Sometimes lives in part of a woodrat den or an abandoned burrow of another mammal. Lives in deserts, usually on rocky soil with sparse vegetation, but also occurs on sandy flats and in desert grassland and chaparral.    
Rodentia Muridae North American Deermouse Peromyscus maniculatus Lower Risk (nt) as P. m. anacapae and P. m. clemintis, otherwise Lower Risk (lc) Panhandle of Alaska and across N Canada, south through most of continental USA, excluding the SE and E seaboard, to southernmost Baja California Sur and to NC Oaxaca, Mexico; including many land bridge islands 74, 1175           Woodland forms climb very well and are semi-arboreal. Feeds on seeds, fruit, insects, subterranean fungi and other foods; stores excess in caches. Occupies almost every habitat type, from boreal forest and tundra to desert, prairies, swamps and high mountains.    
Rodentia Muridae Piñon Deermouse Peromyscus truei Lower Risk (nt) as P. t.. comanche, otherwise Lower Risk (lc) USA, SW and C Oregon to W and SE Colorado, south to N Baja California Norte, Mexico, Arizona and New Mexico; isolated populations in N Texas (comanche) and S Baja California Sur (lagunae) 1176 161         Hops away when disturbed, may climb a tree or disappear among rocks if pursued. Eats mostly piñon and juniper seeds, also takes insects and fungi. Prefers piñon and piñon-juniper stands, usually among rocks.    
Rodentia Muridae Western Heather Vole Phenacomys intermedius Lower Risk NW British Columbia and SW Alberta, Canada, south to N New Mexico, C Utah and N California; disjunct populations in EC California and W Nevada   305         Mainly crepuscular or nocturnal. Usually solitary but may huddle in communal nests in winter. Habitat is heather meadows, alpine areas and open coniferous forest with a dense cover of low shrubs; usually found at 4,000-12,000ft, sometimes at lower elevations.    
Rodentia Muridae Western Harvest Mouse Reithrodontomys megalotis Lower Risk SC British Columbia and SE Alberta, Canada; through much of W and NC USA; south to N Baja California Norte and through interior Mexico to C Oaxaca 1018 167         Feeds on small seeds, moth larvae, beetles and other insects. Nests are usually well concealed on the ground or low in vegetation. Prefers wet meadows and overgrown fields; also found in dry areas and clearing in forests.    
Rodentia Muridae Salt-marsh Harvest Mouse Reithrodontomys raviventris U.S. ESA - Endangered; IUCN - Endangered as R. r. raviventris, Lower Risk (cd) as R. r. halicoetes Salt marshes around San Francisco Bay, California   169         Climbs well among marsh vegetation. Adapted to a wet environment; is a buoyant and strong swimmer; its fur stays dry for a time in water. Lives in the middle and upper zone of salt marshes; favors pickleweed and thick damp grass.    
Rodentia Muridae Arizona Cotton Rat Sigmodon arizonae Extinct as S. a. arizonae, Lower Risk (nt) as S. a. plenus, otherwise Lower Risk (lc) Extreme SE California, SC Arizona and extreme SW New Mexico; south along coastal plain and adjoining foothills, sea level-1900 m, in W Mexico to S Nayarit             Habits similar to Hispid Cotton Rat. Mainly crepuscular. Probably breeds year-round; litter size is 5-12. Habitat is grassy borders of ponds, irrigated fields and stream banks; also in mesquite desert with sparse grass.    
Rodentia Muridae Hispid Cotton Rat Sigmodon hispidus Lower Risk (nt) as S. h. eremicus and S. h. insulicola, otherwise Lower Risk (lc) SE USA, from S Nebraska to C Virginia and south to SE Arizona and peninsular Florida; NW Chihuahua to N Tamaulipas, south through interior Mexico at least to C Zacatecas and W San Luis Potosi 76, 1177           Mainly crepuscular, but can be active at any time. Broad distribution, abundance and daytime activity make this one of the more conspicuous small rodents. Habitat is tall-grass prairies, meadows, agricultural areas and oldfields; favors areas with dense vegetation but also occurs in mesquite desert with little ground cover.    
Rodentia Geomyidae Baird's Pocket Gopher Geomys breviceps   Western Louisiana, eastern Texas, eastern Oklahoma, and  southwestern Arkansas.   383              
Rodentia Geomyidae Plains Pocket Gopher Geomys bursarius Lower risk Southcentral Manitoba, Canada to northwest Indiana, southcentral Texas and northeastern New Mexico. 690   X            
Rodentia Heteromyidae Agile Kangaroo Rat Dipodomys agilis   Southwestern and south central California. 1322   Lower Risk (lc)   Eats seeds of grasses, herbs and shrubs, as well as acorns, juniper berries and a few insects. Habitat is coastal sage scrub, chaparral and piñon-juniper, usually on sandy soils. Habitat is coastal sage scrub, chaparral and piñon-juniper, usually on sandy soils. Prefers flat ground and dry washes. Specific distinctness of northern populations with 2n=62 (agilis) from southern forms with 2n=60 (simulans) documented by Best et al. (1986) and Sullivan and Best (1997a).  Reviewed, in part, by Best (1978, 1983a) and Lackey (1967); see also Hall (1981:1179). Sullivan and Best (1997) and Williams et al. (1993) each listed two valid subspecies, with synonyms.    
Rodentia Heteromyidae California Kangaroo Rat Dipodomys californicus   South central Oregon, northwestern Nevada, and northern California to north of San Francisco Bay.   324 Lower Risk (lc)   Eats mostly seeds of shrubs and grasses; does not store seeds in burrow but makes small caches in soil. Habitat is brushy hills and chaparral; avoids dense vegetation. Also found on well-drained rocky or stony soils.  Sometimes burrows under boulders. Considered distinct from heermanni based on chromosomal (Fashing, 1973) and biochemical data (Patton et al., 1976).  Hall (1981:578) listed californicus as a subspecies of heermanni, without discussion of Patton et al. (1976). Reviewed by Kelt (1988b, Mammalian Species No. 324). Williams et al. (1993) regarded eximius Grinnell and saxatilis Grinnell and Linsdale as valid subspecies.    
Rodentia Heteromyidae Desert Kangaroo Rat Dipodomys deserti   Deserts of eastern California, to southern and western Nevada, southwestern Utah, western and south central Arizona (USA), northwestern Sonora and northeastern Baja California (Mexico). 1324 339 Lower Risk (lc)     Lives in sand dunes and hot dry deserts with loose, deep sandy soils. Revised by Nader (1978).  Reviewed by Best et al. (1989, Mammalian Species No. 339).  Williams et al. (1993) regard each named form as valid subspecies.  Mainly nocturnal, but may actively excavate new burrows or remove sand from existing burrows during the day. Burrows have several entrances, often under shrubs, leading to a maze of tunnels with food storage and a nest chamber.    
Rodentia Sciuridae Yellow-pine chipmunk Tamias amoenus   Northwestern United States; Idaho, Washington Oregon, northern Nevada and Utah, western Wyoming and Montana, and mountainous areas of California. 1913, 1914 390 Least concern            
Rodentia Sciuridae Least chipmunk Tamias minimus   North central states including Minnesota, Wisconsin, and northern Michigan.  Also occupies much of the Rocky Mountains and western Great Plains. 108 653 Least concern            
Rodentia Sciuridae Uinta chipmunk Tamias umbrinus   Mountainous areas of Nevada, Utah, Arizona, California, Colorado, Wyoming, Idaho, and Montana.     Least concern            
Rodentia Sciuridae Belding's ground squirrel Urocitellus beldingi   Mountainous areas of the western United States; eastern Oregon, southwestern Idaho, much of Nevada, and northeastern California. 1107, 1887 221 Least concern            
Rodentia Sciuridae Merriam's ground squirrel Urocitellus canus   Much of eastern Oregon, northwestern Nevada, extreme northeastern California, and southwestern Idaho.     Least concern            
Rodentia Heteromyidae Heermann's Kangaroo Rat Dipodomys heermanni Listed by U.S. ESA and California Dept. of Fish and Game – Endangered as D. h. morroensis; U.S. ESA – Presumed Extinct as D. h. berkleyensis [sic]. Inner coastal ranges and western slopes of Sierra Nevada in central California (USA). 255, 1096 323 Critically Endangered as D. h. morroensis, Vulnerable as D. h. berkeleyensis, Lower Risk (nt) as D. h. dixoni, otherwise Lower Risk (lc).     Lives in coastal plains, valleys, in grassy areas or chaparral and on sparsely vegetated hills; found on fine, deep sandy soils and shallow rocky areas. Revised by Grinnell (1922).  Does not include californicus, see Patton et al. (1976), Williams et al. (1993), and comment under that species.  Reviewed by Kelt (1988a, Mammalian Species No. 323). Williams et al. (1993) recognized all but streatori Merriam as valid subspecies.  Usually emerges for about 40 minutes soon after dusk, but may remain below-ground until moonset on nights with a full moon. Unlike most kangaroo rats, it cannot survive without free water from sources like dew, moist food or puddles.    
Rodentia Heteromyidae Giant Kangaroo Rat Dipodomys ingens U.S. ESA Endangered; California Dept. of Fish and Game – Endangered. Extirpated over much of its original range. Western edge of Joaquin Valley, adjacent Carrizo and Elkhorn plains and upper Cuyama Valley of west central California (USA). 787, 1097 377 Critically Endangered     Prefers open desert with scattered shrubs and grasses on sandy loam soils. Reviewed by Williams and Kilburn (1991, Mammalian Species No. 377) and Williams et al. (1993).  Active for short periods soon after dusk, also occasionally emerges during the day. Stockpiles seed in piles on the surface; moves seeds underground after they have dried. Actively defends its small territory from other kangaroo rats and also from birds or mammals raiding its seed piles.    
Rodentia Heteromyidae Merriam's Kangaroo Rat Dipodomys merriami   Northwestern Nevada and northeastern California to Texas, south to Baja California Sur, northern Sinaloa and Mexican Plateau to San Luis Potosi, Mexico. 1327, 1328   Critically Endangered as D. margaritae and D. insularis; Data Deficient as D. m. collinus and D. m. parvus; otherwise Lower Risk (lc).   Eats a variety of seeds, also green plant material and some insects. Habitat is open deserts with scattered grasses and shrubs, on sand, clay or gravelly soils. Revised by Lidicker (1960).  Includes insularis Merriam, viewed as a separate species by Lidicker (1960; see also Huey, 1964, Hall, 1981, and Best and Thomas, 1991a, Mammalian Species No. 374), but as a subspecies of merriami by Best and Janecek (1992), Williams et al. (1993), and Patton and Alvarez-Castañeda (2000).  Also includes margaritae Merriam (see Lidicker, 1960; Williams et al., 1993; Patton and Alvarez-Castañeda, 1999), which has been considered by others to be a distinct species (Best, 1992, Mammalian Species No. 400; Hall, 1981; Huey, 1964).  The inclusion of both insularis and margaritae within merriami is supported by mitochondrial DNA sequence data (Riddle et al., 2000b), although these same data may eventually result in separation of populations of merriami (including insularis and margaritae) from the southern half of the Baja California Peninsula as a species separate from the remaining parts of the species’ range.  This species makes short simple burrows that do not result in a mound; entrances are usually under a shrub.    
Rodentia Heteromyidae Chisel-toothed Kangaroo Rat Dipodomys microps   Southeastern Oregon and southwestern Idaho, south through northwestern and southeastern California, Nevada, and western Utah, to northwestern Arizona (USA).   389 Vulnerable as D. m. leucotis, Data Deficient as D. m. alfredi, otherwise Lower Risk.   Eats more leaves than seeds and will climb into shrubs to harvest food. Prefers desert valleys dominated by saltbush and upland deserts with blackbush; less common in other desert communities and on sand dunes. Revised by Hall and Dale (1939); reviewed by Csuti (1979) and Hayssen (1991, Mammalian Species No. 389). Williams et al. (1993) listed valid subspecies.  Stores food in burrow.    
Rodentia Heteromyidae San Joaquin Valley Kangaroo Rat Dipodomys nitratoides U.S. ESA – Endangered as D. n. nitratoides and D. n. exilis; California Dept. of Fish and Game - Endangered as D. n. exilis; D. n. nitratoides is of Special Concern; and D. n. brevinasus is California Fully Protected. Southern San Joaquin Valley, west central California. 1330 381 Critically Endangered as D. n. .exilis and D. n. nitratoides, Lower Risk (nt) as D. nitratoides and as D. n. brevinasus.     Dry grassland and desert valleys, often on alkaline soils. Revised by Grinnell (1922) and reviewed by Best (1991, Mammalian Species No. 381) and Williams et al. (1993).  Considered closely related to merriami, but clearly distinct based on morphological (e.g., baculum, Best and Schnell, 1974), chromosomal (Stock, 1974), and molecular (Johnson and Selander, 1971; Patton et al., 1976) characters.  Makes mounds 6-10ft wide, usually under shrubs; stores seeds in pits in the burrow walls. Cannot maintain burrows or keep seed supplies dry in cultivated and irrigated areas, but will exploit abandoned farm fields.    
Rodentia Heteromyidae Ord's Kangaroo Rat Dipodomys ordii   Southwestern Saskatchewan and southeastern Alberta (Canada) and southeastern Washington south through Great Plains and intermontane basins of western USA, to Mexican Plateau as far south as Hidalgo (Mexico). 560, 693, 1099, 1352 353 Lower Risk (lc)     Lives in dry grasslands, desert scrub, piñon-juniper and sagebrush, almost always on fine sandy soils or sand dunes. Revised by Setzer (1949) and reviewed by Garrison and Best (1990, Mammalian Species No. 353); subspecies follow Williams et al. (1993).  Does not include compactus, see Schmidly and Hendricks (1976), Baumgardner and Schmidly (1981), and comment under that species.  Williams et al. (1993) provide a list of what they consider as valid subspecies.  Most active on dark cloudy nights, seldom above ground by day or in bad weather. Makes deep burrows, with entrances often under shrubs or on banks.    
Rodentia Heteromyidae Panamint Kangaroo Rat Dipodomys panamintinus   Deserts of eastern California and western Nevada (USA). 1331 354 Lower Risk (lc)     Prefers open desert with scattered shrubs, on sand, gravel or salt-encrusted soils. Also found in open piñon-juniper desert. Reviewed by Intress and Best (1990, Mammalian Species No. 354) and Williams et al. (1993).  Makes a series of erratic leaps if alarmed. Does not climb, but swims well.    
Rodentia Heteromyidae Stephen's Kangaroo Rat Dipodomys stephensi U.S. ESA – Endangered;  California Dept. of Fish and Game – Threatened Riverside, San Bernardino, and San Diego cos. Of southern California.   73 Lower Risk (conservation dependent)     Coastal sage scrub and grassland on sandy or gravelly soils. Relationships to other species of the heermanni group studied by Lackey (1967).  Reviewed by Bleich (1977, Mammalian Species No. 73).  Uses a network of surface trails linking burrow entrances. Sometimes occupies abandoned pocket gopher or ground squirrel burrows.    
Rodentia Heteromyidae Narrow-faced Kangaroo Rat Dipodomys venustus   Outer coast ranges from southern San Francisco Bay to Estero Bay and Gabilan Range of San Benito and Monterey counties, west central California (USA). 1325 403 Lower Risk (lc)   Eats mostly seeds and some green vegetation. Chaparral and mixed chaparral and oak or pine on sandy soils. Revised by Grinnell (1922), who considered elephantinus a separate species.  Best et al. (1996) concluded that elephantinus was only a subspecies of venustus, based on both molecular and morphological comparisons; also see Stock (1974), Schnell et al. (1978), and Hall (1981:574).  Dipodomys venustus, exclusive of elephantinus, was reviewed by Best (1992, Mammalian Species No. 403); elephantinus as a distinct species was reviewed by Best (1986, Mammalian Species No. 255).  Burrow system is rather simple, consisting of one main tunnel and some side branches to a nest and food storage area.    
Rodentia Heteromyidae Dark Kangaroo Mouse Microdipodops megacephalus   Southeastern Oregon, southern Idaho, northeastern and east central California, northern and central Nevada, and westcentral Utah (USA). 1100 46 Vulnerable as M. m. atrirelictus, Data Deficient as M. m. nexus, otherwise Lower Risk.     Prefers sand dunes and deserts with fine sand soils, but where it overlaps with Pale Kangaroo Mouse it is found on gravelly soil. Reviewed by O'Farrell and Blaustein (1974a, Mammalian Species No. 46).  Hafner et al. (1979) discounted the suggestion by Hall (1941:380-382) of hybridization between megacephalus and pallidus.  Also, Hall's suggestion (1981:560) that leucotis may warrant specific status is not supported (see Hafner and Hafner, 1983).  Subspecies listed by Williams et al. (1993).  Feeds in the open, unlike pocket mice. Hibernates November-March.    
Rodentia Heteromyidae Pale Kangaroo Mouse Microdipodops pallidus   Eastcentral California, western and southcentral Nevada (USA).   47 Vulnerable as M. p. restrictus, otherwise Lower Risk (lc).   Small seeds and insects. Habitat is sand dunes and valleys with fine soft sand. Reviewed by O'Farrell and Blaustein (1974b, Mammalian Species No. 47).  Subspecies follow Williams et al. (1993).  Very similar to Dark Kangaroo Mouse. Is most active 1-2 hours after sunset.    
Rodentia Heteromyidae Bailey's Pocket Mouse Chaetodipus baileyi   Southern Arizona, southwestern New Mexico (USA), south to northern Sinaloa (Mexico). 1245 297 Lower Risk (lc)   Eats a variety of seeds, including jojoba which is normally toxic to mammals. Habitat is deserts with shrubs or cactus and sparse grasses. Reviewed by Paulson (1988a, Mammalian Species No. 297).  Species now restricted to populations and subspecies from east of the Colorado River in Arizona, SW New Mexico, Sonora, and N Sinaloa; those from west of the Colorado River in California and Baja California are now regarded as C. rudinoris (see account below and Riddle et al., 2000a).  Active year round.    
Rodentia Heteromyidae California Pocket Mouse Chaetodipus californicus   Central California (USA) to northern Baja California (Mexico). 1093   Data Deficient as C. c. femoralis, otherwise Lower Risk (lc).     Prefers dense chaparral; less common in dry grassland and desert scrub. Subspecies listed by Hall (1981) and Williams et al. (1993).  Mainly active on the ground, but also climbs shrubs and small trees when feeding. Can become torpid by day at any time of year and is inactive in cold wet weather.    
Rodentia Heteromyidae San Diego Pocket Mouse Chaetodipus fallax   Southwestern California (USA) to western Baja California (Mexico). 1094 517 Data Deficient as C. h. fallax and C. h. pallidus, otherwise Lower Risk (lc)     Habitat is low to high deserts, usually in rocky or gravelly areas. Reviewed by Huey (1960; 1964) and Lackey (1996, Mammalian Species No. 517).  Includes anthonyi, considered a full species by Hall (1981) but a subspecies by Williams et al. (1993).  Subspecies reviewed by Williams et al. (1993).  Breeds in spring and summer; litter size is 3-6 and females may have more than 1 litter per year.    
Rodentia Heteromyidae Long-tailed Pocket Mouse Chaetodipus formosus   Western Utah, Nevada, eastern California, and northwest Arizona (USA), and eastern coast of Baja California to Bahía Concepcion (Baja California Sur, Mexico).     Lower Risk (lc)     Usually found among rocks or on gravelly soils in shrubby deserts; occasionally found in sandy soils. Reviewed by Huey (1964).  Included in Perognathus by Hall (1981:542) and earlier workers, but allocated to Chaetodipus by Patton et al. (1981) and Hafner and Hafner (1983).  Subspecies reviewed by Williams et al. (1993).  Inactive in cold weather and for most of the winter.    
Rodentia Heteromyidae Desert Pocket Mouse Chaetodipus penicillatus   Southeastern California and southern Nevada to southern Arizona and southwestern New Mexico to northeastern Baja California and Sonora, Mexico. 1095 767 Lower Risk (lc)   Eats mainly seeds. Habitat is sandy, open deserts with sparse vegetation; avoids rocky soil. Revised by Hoffmeister and Lee (1967).  Subspecies reviewed by Williams et al. (1993).  Excludes Chihuahuan Desert subspecies atrodorsalis and eremicus, now regarded as a separate species, C. eremicus (see account above and Lee et al., 1996).  Sometimes climbs small trees or shrubs in search of food.  Becomes torpid in winter, staying in burrow and eating stored seeds.    
Rodentia Heteromyidae Baja California Pocket Mouse Chaetodipus rudinoris   Southeastern California south to Cape Region of Baja California Sur, Mexico.     Lower Risk (lc)     Reviewed, in part as C. baileyi, by Paulson (1988a, Mammalian Species No. 297).  Chromosomal (Patton and Rogers, 1993), allozyme (Patton et al., 1981), and mitochondrial DNA (Riddle et al., 2000b) support species status for populations from west of the Co      
Rodentia Heteromyidae Spiny Pocket Mouse Chaetodipus spinatus   Southern Nevada, southeastern California (USA) south to Cape Region of Baja California Peninsula (Mexico). 751 385 Lower Risk (lc)     Habitat is rocky slopes and boulders with sparse vegetation. Reviewed by Lackey (1991b, Mammalian Species No. 385).  Subspecies reviewed by Williams et al. (1993) and Patton and Alvarez-Castañeda (1999).  Habits are poorly known.    
Rodentia Heteromyidae White-eared Pocket Mouse Perognathus alticolus   Southcentral California   463 Critically Endangered as P. a. alticola; Lower Risk as P. a. inexpectatus.     Habitat is dry grassland and dry shrub habitats, also open pine forest. Subspecies listed by Hall (1981), Williams et al. (1993); may be only subspecifically distinct from parvus.  Reviewed by Best (1994a, Mammalian Species No. 463).  Habits are poorly known.    
Rodentia Heteromyidae San Joaquin Pocket Mouse Perognathus inornatus   Sacramento, San Joaquin and Salinas valleys and adjacent foothills, and Western Mojave Desert, of California. 695 450 Lower Risk (nt) as P. i. neglectus and P. i. psammophilus; otherwise Lower Risk (lc).     Habitat is dry grassland and desert scrubs, usually in sandy areas, but sometimes found on rocky slopes. Revised by Osgood (1918); subspecies listed by Williams et al. (1993) who allocated psammophilus (with sillimani as a synonym) to this species, not to longimembris where this name has been usually placed (Hall, 1981; Patton, 1993b).  As noted by Williams et al. (1993), at least two and possibly three distinct species are currently included under the name inornatus.  Reviewed by Best (1993e, Mammalian Species No. 450).  Not a good climber and usually feeds on the ground.    
Rodentia Heteromyidae Little Pocket Mouse Perognathus longimembris U.S. ESA – Endangered as P. l. pacificus. Southeastern Oregon and western Utah (USA) south to northern Sonora and Baja California and Baja California Sur (Mexico) (see Alvarez-Castañeda et al., 2001).     Critically Endangered as P. l. pacificus, Vulnerable as P. l. brevinasus, Data Deficient as P. l. bangsi and P. l. internationalis; otherwise Lower Risk (lc).     Habitat is desert scrub, on sandy or gravelly soils with sparse vegetation. Also found in dry grassland and coastal sage. Revised by Osgood (1918); subspecies listed by Hall (1981) and Williams et al. (1993), who placed psammophilus von Bloeker with P. inronatus instead of longimembris, where this taxon has usually been assigned (Hall, 1981; Patton, 1993b).  Stays below ground for up to 9 months in winter, arousing from torpor occasionally to feed on stored seeds.    
Rodentia Heteromyidae Great Basin Pocket Mouse Perognathus parvus   Great Basin from southern British Columbia (Canada), south to eastern California and east to southeastern Wyoming and northwestern Arizona (USA). 752, 753 318 Lower Risk (lc) as P. parvus and P. xanthanotus.     Prefers dry sandy regions dominated by sagebrush, but also occurs in grassland, desert and open woodlands. Reviewed by Verts and Kirkland (1988, Mammalian Species No. 318).  Includes xanthonotus (Williams et al., 1993), often considered a distinct species (Hall, 1981; Patton, 1993b; Verts and Kirkland, 1988, by omission).  Remains belowground November-March. Breeds April-October; litter size is 2-8.    
Rodentia Muridae House Mouse Mus musculus Lower risk Every state in the United States. 92, 754                
Rodentia Muridae Brown Rat Rattus norvegicus Lower risk Scattered across the United States but very scarce, in not absent, from the Rocky Mountains (might looks this way because of sampling effort). 755, 756, 757, 758                
Rodentia Muridae Roof Rat Rattus rattus Lower risk Distributed around the outside of the country.  Not many records of this species being collected in the interior of the country (this might be because of sampling effort). 759, 760                
Rodentia Sciuridae White-tailed antelope squirrel Ammospermophilus leucurus   Southeastern Oregon and southwestern Idaho through most of Utah and Nevada, includes western Colorado, northwestern New Mexico, Northern Arizona, interior, southern, and central California. 112 368 Least concern            
Rodentia Sciuridae Golden-mantled ground squirrel Callospermophilus lateralis   Mountains of western United States and Canada. 100, 1108, 1726, 1727, 1885 440 Least concern            
Rodentia Sciuridae Northern flying squirrel Glaucomys sabrinus   Alaska and Canada, northwestern United States to southern California and western South Dakota, northeastern United States to southern Appalachian Mountains. 1020 229 Least concern            
Rodentia Sciuridae Yellow-bellied marmot Marmota flaviventris   Western United States through the Rocky Mountains, Sierra Nevada and Intermountain west. 106 135 Least concern       M. f. engelhardti reported from Washington County, Utah - 20 miles from AZ border    
Rodentia Sciuridae Rock squirrel Otospermophilus variegatus   Nevada to southwestern Texas and Utah to Puebla. 951 272 Least concern            
Carnivora Canidae Eastern Coyote Canis latrans Common Throughout continental US. 265 (C), 1126, 1127 (B), 1267 79         Larger than western coyote.    
Carnivora Canidae Red Fox Vulpes vulpes Common Throughout the US except in the southwest. 435 (W), 436 (Y), 582 537         This species helps keep small mammal populations in check; white tail tip.    
Carnivora Canidae Kit Fox Vulpes macrotis Common Southwestern US. 269, 1208 (B) 123         Smallest North American canid.  Large ears and black tail tip.    
Carnivora Canidae Grey Fox Urocyon cinereoargenteus Common Nationwide except for the northwest. 584 189         Black dorsal stripe on tail; climbs trees.    
Carnivora Canidae Channel Islands Fox Urocyon littoralis Rare Channel Islands of California.   489         Similar to grey fox but smaller.  This species is a conservation concern.    
Carnivora Ursidae Black Bear Ursus americanus Common Northeast, Great Lakes region, Appalachians, Arkansas and west; Alaska and northern Canada but absent in Nevada and Great Plains.  Southern distributions spotty into Mexico. 142 (C),1132 (S) 647         Usually not aggressive. Adults climb trees.   Black color most common, cinnamon and white phases also exist.    
Carnivora Mustelidae American Marten Martes americana Common within range Extreme northern New England, mountain ranges of western US, Canada, and Alaska.   289         Found in isolated pockets of habitat.    
Carnivora Mustelidae Fisher Martes pennanti Common Southern Canada to northeastern and midwestern US. 590 (C) 156         Larger and less arboreal than martens.  Successfully preys on porcupines.    
Carnivora Mustelidae Ermine or Short-tailed Weasel Mustela erminea Common All of Canada, northeastern US, Great Lakes region, northwestern US. 588 (P), 1051 (P) 195         Color varies seasonally, mainly eats rodents and young rabbits, as well as small vertebrates and invertebrates.  Nocturnal.    
Carnivora Mustelidae Long-tailed weasel Mustela frenata Common Southwestern Canada, everywhere south of Canada/US border to South America except arid desert areas of southwest US and northwest Mexico. 1348 570         Prefers rodents, but feeds on a broad array of small vertebrates.  Agile swimmer.  Northern populations vary in color seasonally, but not southern populations.    
Carnivora Mustelidae Wolverine Gulo gulo Rare within the 48 contiguous US. Alaska, Rocky Mountains, isolated pockets in the Sierras. 442 (C), 807 (S), 1295 (S), 1296 (S), 1297 (S) 499         Largest member of the mustelid (weasel) family, wolverines consume much carrion but are also efficient predators who prey on animals as large as caribou.  If necessary they also feed on berries.    
Carnivora Mustelidae American Badger Taxidea taxus Common within range Western and central North America, from central Canada to central Mexico. 701 (C), 702 (A), 703 (H) 26         Because of their secretive and fossorial (digging) habits badgers are not often seen.  Persecuted by humans, though sometimes inadvertently when taking poisoned meat meant for wolves and coyotes.    
Carnivora Mustelidae Northern River Otter Lontra canadensis Common in the northern part of its range, uncommon to extirpated in southern parts of its range. Alaska and most of the continental US except for much of the southwestern continental US. 802 (A), 859 (W) 587         Playful, likes to slide on the snow.  Eats fish and other aquatic or amphibious animals.    
Carnivora Mustelidae Sea Otter Enhydra lutris Rare in the southern part of its range, but common elsewhere. Southern coast of Alaska, coastal regions of Washington and California. 799, 800 (B), 801 (B), 1298 (S) 133         Marine.  Eats crustaceans, molluscs, and sometimes fish.  Prefers bed of brown algae and giant kelp.    
Carnivora Mephitidae Western Spotted Skunk Spilogale gracilis Unknown Western continental US.   674         Other than what is known about skunks in general, not much is known about this species specifically.    
Carnivora Mephitidae Striped Skunk Mephitis mephitis Common Throughout continental US except a small area in southern California, Nevada, and Arizona. 280 173         Sometimes de-scented and kept as pets (not recommended).  Good "mouser" and will use cat litter boxes.    
Carnivora Otariidae Northern Fur Seal Callorhinus ursinus Some populations depleted, while others are doing well West coast from central Alaska to southern California. 1300 (S), 1301, 1302           There are no subspecies of this animal because they range so widely that genetic material is spread throughout the entire population.  Populations were threatened by hunting, but have rebounded after governmental management was instituted.    
Carnivora Otariidae Guadalupe Fur Seal Arctocephalus townsendi Vulnerable or threatened Pacific coast of southern California.   700         Only member of the genus found in the Northern Hemisphere.  Males defend territories often including caves along beaches that provide shade.    
Carnivora Otariidae Stellar Sea Lion Eumetopias jubatus East of 144º W threatened, west of 144º it is endangered. Pacific coast from south central Alaska south to California. 1270 (FM), 1303 (M) 283         Largest member of the Otariidae family.  Generally eat schooling fish, octopus, or squid but might take smaller seals.    
Carnivora Otariidae California Sea Lion Zalophus californianus Common Pacific shore of southern California.             Population is increasing.  Often seen in wildlife conservation parks (zoos), aquaria, and circuses.  Mainly eats fish.    
Carnivora Phocidae Harbor Seal Phoca vitulina Common All of west coast from southern Alaska south to Mexico; also New England south to Delaware along the east coast. 135           Unlike many other seal species, harbor seals have an annual reproductive cycle.  Prey on a large range of swimming and bottom dwelling ocean species, mainly fish.  Dives can be deep and last up to a half an hour.    
Carnivora Phocidae Northern Elephant Seal Mirounga angustirostris Recovering from overhunting West coast of US, principally off the coast of California. 134, 282 (Y), 449, 450 (FY), 451 (G), 452 (A), 453 (A)                
Carnivora Procyonidae Ringtail, Bassarisk, or Cacomistle Bassariscus astutus Common Southwestern US from the Gulf of Mexico to the west coast. 858 327         Nocturnal and seldom seen.  Good climber of rocks and trees.  Solitary and territorial, but can be densely populated in good habitat.    
Carnivora Procyonidae Raccoon Procyon lotor Common Common throughout US except portions of California, Arizona, and New Mexico. 140, 709 (S) 119         Raccoons are extremely adaptable and can live in a wide range of temperatures.  They are found virtually anywhere there is water.  Their diet is extremely varied including plant and animal material.  The forefeet of raccoons end in highly sensitive hand-l    
Carnivora Felidae Mountain Lion, Puma, or Cougar Puma concolor Stable in the western, Endangered in Florida. Western contiguous US, small population in Florida. 275, 276, 586           Cougars are active mainly at dusk, night, and dawn.  Most of their prey consists of larger animals such as ungulates, but turtles, rabbit-sized animals, coyotes, and other cougars are taken.  The name "concolor" comes from the even coloration that differs    
Carnivora Felidae Bobcat Lynx rufus Rare or common, depending on geographic region. All of contiguous US, except for parts of California, Utah, Colorado,  agricultural areas of the midwest and coastal areas of the midAtlantic states. 819, 1293 563         As with the Canada lynx, bobcats are very secretive and seldom observed even in areas it occupies.  Slightly smaller than the lynx, it is capable of taking adult white-tailed deer.  Though mainly a carnivore,  areas a large array of plant and animal mater    
Artiodactyla Cervidae Elk Cervus elaphus Common Western US and Canada. 189, 190,191, 318, 809, 1077, 1278                
Artiodactyla Cervidae Mule Deer Odocoileus hemionus Common Southern Alaska to central Mexico, east across US and Canada to South Dakota Nebraska, Kansas, and western Texas.   219              
Artiodactyla Cervidae White-tailed Deer Odocoileus virginianus Common Throughout North America, except northern Canada and very arid areas of western US. 1313 388              
Artiodactyla Antilocapridae Pronghorn Antelope Antilocapra americana Common West-central US with some extensions across the border with Canada and some ranging into central Mexico. 166, 717,718, 823, 1310 90       Open areas      
Artiodactyla Bovidae Bighorn Sheep Ovis canadensis Common in historic range Mountainous and hilly areas of the western contiguous US and southern Canada. 168, 169, 307, 941 230              
Chiroptera Vespertilionidae Big Brown Bat Eptesicus fuscus Lower Risk (lc) Throughout the contiguous US and Alaska 39, 223 356 Lower Risk (lc)       TRIBE Eptesicini    
Chiroptera Vespertilionidae Western Red Bat Lasiurus blossevillii Lower Risk (lc) West coast and southwestern United States     Lower Risk (lc)       TRIBE Lasiurini    
Chiroptera Vespertilionidae Hoary Bat Lasiurus cinereus Lower Risk (lc) Throughout the contiguous United States and Hawaii 656, 041, 042 185 Lower Risk (lc)       TRIBE Lasiurini; *Status is Low Risk eith the exception of L. c. semotus    
Chiroptera Vespertilionidae Southern Yellow Bat Lasiurus ega Lower Risk (lc) Extreme southwest and southern tip of Texas 1537 515 Lower Risk (lc)       TRIBE Lasiurini    
Chiroptera Vespertilionidae Western Yellow Bat Lasiurus xanthinus Lower Risk (lc) Southern California, Arizona, and New Mexico     Lower Risk (lc)       TRIBE Lasiurini    
Chiroptera Vespertilionidae Canyon Bat Parastrellus hesperus Lower Risk (lc) Arid west and southwestern United States     Lower Risk (lc)       TRIBE Pipistrellini    
Chiroptera Vespertilionidae Townsend's Big-eared bat Corynorhinus townsendii Vulnerable Western United States, east to the Rocky Mountains, a few scattered populations in the eastern United States 229 175 Vulnerable       TRIBE Plecotini; *Status is Vulnerable as Plecotus townsendii; Endangered as P. ingens and P. virginianus    
Chiroptera Vespertilionidae Spotted Bat Euderma maculatum Lower Risk (lc) Rocky Mountain area of the United States from Idaho to the western tip of Texas 734 77 Lower Risk (lc)       TRIBE Plecotini    
Chiroptera Vespertilionidae Pallid Bat Antrozous pallidus Lower Risk (lc) Semi-arid Western United States, east to western edge of Kansas 230 213 Lower Risk (lc)            
Chiroptera Vespertilionidae Silver-haired Bat Lasionycteris noctivagans Lower Risk (lc) Throughout the United States except extreme southern protions of southern states.  Also occurs in southeastern Alaska. 658 172 Lower Risk (lc)            
Chiroptera Vespertilionidae Californian Myotis Myotis californicus Lower Risk (lc) Southern Alaska panhandle, western United States from Washington to western tip of Texas   428 Lower Risk (lc)            
Chiroptera Vespertilionidae Western Small-footed Bat Myotis ciliolabrum Lower Risk (lc) Much of the western United States   670 Lower Risk (lc)            
Chiroptera Vespertilionidae Little Brown Myotis Myotis lucifugus Lower Risk (lc) Most of US, except Texas to Nebraska, and extreme southern portions of southern states 224, 225, 814 142 Lower Risk (lc)            
Chiroptera Vespertilionidae Dark-nosed Small-footed Myotis Myotis melanorhinus Not evaluated Washington to western Oklahoma, extending southwest to the western tip of Texas     Not evaluated            
Chiroptera Vespertilionidae Arizona Myotis Myotis occultus Not evaluated Southern California to Arizona, New Mexico, and Colorado, possibly western Texas     Not evaluated            
Chiroptera Vespertilionidae Fringed Myotis Myotis thysanodes Lower Risk (lc) Western tip of Texas to southwestern South Dakota and west to coast   137 Lower Risk (lc)            
Chiroptera Vespertilionidae Long-legged Myotis Myotis volans Lower Risk (lc) Alaska panhandle to California, east to western tip of Texas and western North Dakota   224 Lower Risk (lc)            
Chiroptera Vespertilionidae Yuma Myotis Myotis yumanensis Lower Risk (lc) California north to Washington, east to Montana and western Texas     Lower Risk (lc)            
Chiroptera Phyllostomidae Mexican Long-tongued Bat Choeronycteris mexicana Lower Risk (nt) Southern California, Nevada, Arizona, and New Mexico; a single record from southern Texas   291 Lower Risk (nt)       TRIBE Glossophagini    
Chiroptera Phyllostomidae Lesser Long-nosed Bat Leptonycteris yerbabuenae Not evaluated Central California, southern Arizona, and New Mexico   797 Not evaluated       TRIBE Glossophagini    
Chiroptera Phyllostomidae Californian Leaf-nosed Bat Macrotus californicus Vulnerable Southern Nevada, southern Arizona, and southern California     Vulnerable            
Chiroptera Molossidae Greater Bonneted Bat Eumops perotis Lower Risk (lc) California to Texas   534 Lower Risk (lc)            
Chiroptera Molossidae Pocketed Free-tailed Bat Nyctinomops femorosaccus Lower risk (lc) Southwestern Texas to New Mexico, Arizona, California   349 Lower Risk (lc)            
Chiroptera Molossidae Big Free-tailed Bat Nyctinomops macrotis Lower risk (lc) Southern and western Texas to southern California; southern Nevada, Utah and Colorado; reported from Iowa and Kansas 891 351 Lower Risk (lc)            
Chiroptera Molossidae Brazilian/Mexican Free-tailed Bat Tadarida brasiliensis Lower Risk (nt) From Oregon to North Carolina and south 1549 331 Lower Risk (nt)            
Lagomorpha Leporidae Pygmy Rabbit Brachylagus idahoensis Endangered in WA; otherwise Lower Risk Southwest Oregon to east central California, southwest Utah, north to southwest Montana, west central Washington.   125       Closely associated with dense stands of sagebrush. Mostly crepuscular, but can be seen by day. Walks or scurries instead of walks, and lives in underground burrows.    
Lagomorpha Leporidae Snowshoe Hare Lepus americanus Lower risk Southern and central Alaska to southern and central coasts of Hudson Bay to Newfoundland and Anacosti Island, Canada, south to southern Appalachians, southern Michigan, North Dakota, north central New Mexico, south central Utah, and east central California. 246, 544           Mostly nocturnal or crepuscular; shelters by day under logs or in thick vegetation. Lives in forests and dense thickets, often associated with low wet areas.    
Lagomorpha Leporidae Black-tailed Jackrabbit Lepus californicus Lower risk Hidalgo and southern Queretaro to northern Sonora and Baja California, Mexico; north to southwestern Oregon and central Washington, southern Idaho, eastern Colorado, southern South Dakota, western Missouri, and northwestern Arkansas. Apparently isolated population in southwestern Montana. 060, 245, 1347 530       Sagebrush flats, overgrazed pastures and rangelands, deserts, prairies and agricultural lands. Nocturnal or crepuscular; rests by day in a shallow soil depression, usually in the shade of a bush. Uses speed and agility to avoid predators; usually solitary, but may be seen in pairs or larger groups.    
Lagomorpha Leporidae White-tailed Jackrabbit Lepus townsendii Lower risk Central Alberta and Saskatchewan east to extreme southwestern Ontario, Canada, south to southwestern Wisconsin, Iowa, northwestern Missouri, west through central Kansas to north central New Mexico, west to central Nevada, east central California, US, and north to south central British Columbia, Canada. 1189, 1349 288       Open grasslands, meadows and cultivated areas; less common in sagebrush flats. Mainly nocturnal, but may be active at dawn or dusk.  When pursued, follows a zigzag path with big leaps and bursts of speed.    
Lagomorpha Leporidae Desert Rabbit Sylvilagus audubonii Lower Risk Northeastern Puebla and western Veracruz, Mexico, to north central Montana and southwestern North Dakota, north central Utah, central Nevada, and northcentral California, south to Baja California and central Sinaloa, Mexico. 059, 1188, 1858 106       Habitat is varied, maily in dry lowlands including deserts, grasslands, riparian brush and pinon-juniper woodlands. Most active soon after dawn or at dusk. Retreats from heat of day into burrows made by another species or a shady thicket.    
Lagomorpha Leporidae Brush Rabbit Sylvilagus bachmani Endangered Western Oregon south of Columbia River to Baja California, Mexico, east to Cascade-Sierra Nevada Range, USA.           Dense brush, forest edge, old clear-cuts and burns in forest. Mainly nocturnal, but may emerge to sunbathe during day. Makes tunnels and runways through dense vegetation but does not dig burrows.    
Lagomorpha Leporidae Eastern Cottontail Sylvilagus floridanus Lower Risk Northern, central, and western Venezuela and adjacent islands and adjacent Colombia through Central America (disjunct in part); to northwestern Mexico, Arizona, north and east to North Dakota, Minnesota, northern Michigan, New York and Massachusetts, Atlantic Coast south and Florida Gulf Coast west to Mexico; also southern Saskatchewan, southern Ontario and south central Quebec, Canada. 058, 953 136       Thickets and old fields, edges of hardwood forest, farmland, prairies and swamps. One of most familiar rabbits, mainly nocturnal but may be active and dawns or dusk. Sleeps under brush piles or in thickets or dense grass.    
Lagomorpha Leporidae Mountain Cottontail Sylvilagus nuttallii Lower Risk Intermountain area of North America from southern British Columbia to southern Saskatchewan, Canada, south to eastern California, Nevada, central Arizona and NW New Mexico.   56       Lives in rocky areas in sagebrush flats, riparian areas and gullies near ponderosa pines or spruces. Most active at dawn or dusk. Unlike most rabbits, sometimes climbs trees.    
Soricomorpha Soricidae Crawford's grey shrew Notiosorex crawfordi Least concern Southwestern andsouthcentral United States to Baja California.   17              
Soricomorpha Soricidae Marsh shrew Sorex bendirii Least concern Western half of Oregon and Washington, northwestern California.   27              
Soricomorpha Soricidae Mt. Lyell shrew Sorex lyelli Least concern Occurs only in the central Sierra Nevada mountains of California.             Occurs only above an elevation of 2000 feet.    
Soricomorpha Soricidae Merriam's shrew Sorex merriami Least concern Western United States.   2         Strong preference for dry habitats.    
Soricomorpha Soricidae Dusky shrew Sorex monticolus Least concern Much of Alaska south to northern Mexico.  Pacific coast east to the northern Great Plains.   528         Also known as the Montane shrew.    
Soricomorpha Soricidae Ornate shrew Sorex ornatus Least concern Occurs discontinuously from around 39º N down to the  tip of the Baja peninsula.   212              
Soricomorpha Soricidae Pacific shrew Sorex pacificus Least concern Occurs along the Pacific shore from Oregon down to central California.   231              
Soricomorpha Soricidae Water shrew Sorex palustris Least concern Southern Alaska and the northern and mountainous areas of the United States. 1287 296              
Soricomorpha Soricidae Preble's shrew Sorex preblei Least concern Northwestern United States.   416              
Soricomorpha Soricidae Fog shrew Sorex sonomae Least concern Coastal areas of northern California and Oregon.                  
Soricomorpha Soricidae Inyo shrew Sorex tenellus Least concern Mountain areas of California and Nevada.   131              
Soricomorpha Soricidae Trowbridge's shrew Sorex trowbridgii Least concern Western Washington and Oregon and mountainous areas of California.   337              
Soricomorpha Soricidae Vagrant shrew Sorex vagrans Least concern Along the Pacific coast to central coastal California, throughout Oregon and Washington, western Montana, western and southern Idaho, Northern and east central Nevada, northern and extreme west central Utah, and extremem western Wyoming. 1288 744              
Soricomorpha Talpidae Shrew mole Neurotrichus gibbsii Least concern South west British Columbia Canada to west central California. 727, 728 387         Active both night and day; does not form molehills when making tunnels. Swims well; does not hibernate; appears to be relatively social. Habitat is willow or alder thickets along streams and other moist, low lying areas with soft soil.    
Soricomorpha Talpidae Broad-footed mole Scapanus latimanus Least concern South central Oregon to northern Baja California and Mexico.   666         Makes temporary foraging tunnels just below the soil surface, leaving a visible ridge in the soil. Feeds mainly on earthworms. Favors rich damp soils with little vegetation; avoids heavy clay or stony soils.    
Soricomorpha Talpidae Coast mole Scapanus orarius Least concern Southwestern British Columbia, Canada to northwestern California , west central Idaho, northern Oregon, central and southeast Washington. 346 253         Adults remain underground but young apparently disperse on the surface and may fall prey to Barn Owls or house cats. Breeds early in the year; litter size is 2-4. Habitat is well-drained, often sandy soil in open meadows, brush and woods; avoids very wet    
Soricomorpha Talpidae Townsend's mole Scapanus townsendii Least concern South western British Columbia, Canada to northwestern California.   434         Makes surface ridges and deeper tunnels. Nests are marked by a very large mound or "fortress" of small mounds; makes a large nest chamber 6-8 inches below surface lined with green grass with an inner lining of dry grass. Lives in moist to wet meadows, riv    
Didelphimorphia Didelphidae Virginia Opossum Didelphis virginiana least concern found everywhere except NV, MT, UT, ND, SD, WI, MN, WY 3, 4, 630, 828, 829, 830 40         Nocturnal, introduced to the western states in the early 1900s    
Rodentia Aplodontidae Mountain Beaver Aplodontia rufa common forest areas W of Cascades exc interior valleys 742, 743 431         tend to be asoicial exc during reproduction    
Rodentia Erethizontidae Common Porcupine Erethizon dorsatum common   82, 870 29         active throughout year    
Lagomorpha Ochotonidae Pika Ochotona princeps common   63, 64 352              
Cetacea Balaenopteridae Common Minke Whale Balaenoptera acutorostrata Lower Risk Worldwide: arctic to tropical waters       no carnivore aquatic, marine Before a dive, raises tail stock above the water but usually does not expose flukes. Mainly seen alone or in pairs but may congregate in groups of 100 or more at feeding areas. Lives in coastal and offshore waters.    
Cetacea alaenopteridae Blue Whale Balaenoptera musculus U.S ESA - Endangered; IUCN - Endangered as B. m. intermedia, Data Deficient as B. m. brevicauda; Endangered as B. musculus except Vulnerable in North Atlantic and Lower Risk (cd) in North Pacific Worldwide: arctic to tropical waters 578, 808, 1215, 1216     no carnivore aquatic, marine One of the fastest whales; can travel at 30 mph if pursued. Feeds almost exclusively on krill. Usually seen alone or in small groups. Often found on the edge of continental shelves but also in deep water and in shallow inshore water.    
Cetacea alaenopteridae Fin Whale Balaenoptera physalus Endangered Worldwide: arctic to tropical waters 769     no carnivore aquatic, marine One of the more commonly seen large whales in the W. North Pacific. Also one of the fastest whales; can travel at 20 mph. Favors continental shelf waters, but also found in coastal and offshore waters; less common in tropical waters.    
Cetacea alaenopteridae Humpback Whale Megaptera novaeangliae U.S. ESA - Endangered; IUCN - Vulnerable Worldwide: cold-temperate to tropical waters 575, 576, 698, 768 604   no carnivore aquatic, marine Acrobatic; leap clear of water when breaching; frequently slaps water with flippers or tail. Feeds on schooling fish or krill; groups may cooperate to trap prey. In winter and summer, found in coastal areas or near islands; migrates through open oceans.    
Cetacea Eschrichtiidae Gray Whale Eschrichtius robustus U.S. ESA - Endangered, except for Eastern North Pacific Ocean - coastal and Bering, Beaufort and Chukchi Seas populations which are Delisted Taxa; IUCN - Critically Endangered in Northwest Pacific, otherwise Lower Risk North Pacific: warm temperate to arctic waters. Formerly present int he North Atlantic. Sometimes enters tropical water at the southern boundaries of its distribution. The eastern and western North Pacific populations are separate. The eastern population is distributed from Baja California and the adjacent coast of Mexico to the Bering and Chukchi Seas. The western population is distributed from the East China Sea to the Sea of Okhotsk 833, 834, 835, 836, 837, 1135, 1136, 1217, 1308     no carnivore aquatic, marine When traveling, typically blows 3-5 times at intervals of 15-30 seconds, then dives for 3-5 minutes. Feeds by sucking up amphipods and other invertebrates from the sea floor. Found in coastal waters.    
Cetacea Delphinidae Long-beaked Common Dolphin Delphinus capensis Lower Risk Worldwide: near-shore tropical to temperate waters 579     no carnivore aquatic, marine Similar to Short-beaked Common Dolphin. Average group size around 200. Habitat is near-shore waters.    
Cetacea Delphinidae Short-beaked Common Dolphin Delphinus delphis Lower Risk, except for Mediterranean subpopulation which is Endangered Worldwide: temperate and tropical waters, including the Black Sea       no carnivore aquatic, marine Bouncy and acrobatic; often leaps high out of the water. May bow-ride for extended periods and will follow the bow waves of large whales. Highly social - group size averages about 100 but can number several thousand. Habitat mainly in deep continental shelf and offshore waters, occasionally near shore.    
Cetacea Delphinidae Risso's Dolphin Grampus griseus Data deficient Worldwide: temperate to tropical waters 1055     no carnivore aquatic, marine May move slowly, showing only dorsal fin, but can be active, leaping and slapping with flippers or flukes. Habitat is deep waters.    
Cetacea Delphinidae Bottlenose Dolphin Tursiops truncatus Data deficient Worldwide: temperate to tropical waters, including the Black Sea 262     no carnivore aquatic, marine Attracted to boats and often bow-rides or travels at the stern. Sometimes acrobatic when feeding. Habitat is coastal, shelf and offshore waters, with separate populations in inshore and pelagic waters.    
Cetacea Phocoenidae Dall's Porpoise Phocoenoides dalli Lower Risk North Pacific: cold-temperate waters 1060 319   no carnivore aquatic, marine A fast, energetic swimmer; groups unusually numbering 2-12 often bow-ride or accompany boats. Habitat is coastal and offshore waters.