Small mammals of the UCSC Campus Natural Reserve

Here are a few of the small mammals species that can be found on the main UCSC campus, including on the Campus Natural Reserve

By Gabby Reynosa, UCSC Biology (2019), Small Mammal Undergraduate Research in Forests (SMURF) intern fall 2018 and spring 2019

SMURF internship website

Small Mammal ID guide---Forest Ecology Research Plot and Fort Ord Natural Reserve

(All animals were photographed during research conducted under a California Department of Fish and Wildlife Scientific Collecting Permit for the UCSC Natural Reserves, SCP#12383)

 Microtus californicus, California vole

California vole

(Photo: Alex Jones, UCSC Campus Natural Reserve)

Body Size: 120.5-146mm

Characteristics: grizzled brown color on back, often flecked with black

and lighter gray below, bicolored tail, pale brown or grayish feet, inconspicuous furred ears

Habitats (range-wide): dry, grassy slopes, salt or freshwater marshes, damp meadows;

variety of elevations

Habitats (UCSC): grassland, coastal prairie, occasionally within openings in mixed-evergreen forest

Range: Southwest Oregon, most of California

Lifespan: 1 year

Diet: grasses, seeds, vegetation

Reproduction: breed through the year; first reproduce at 2 months old; 1 or more litters per year;

4-8 offspring per litter; gestate for  21 days; weaned at 17 days

 Neotoma fuscipes, Dusky-footed woodrat

dusky-footed woodrat

(Photo: Gabby Reynosa, SMURF intern)

Body Size: 158-257mm

Characteristics: gray/buff brown on back, pale gray/white underneath, head usually grayer than body

Habitat: hardwood forests and dense shrublands

Habitat (UCSC): northern maritime chaparral, mixed-evergreen forest, redwood forest

Range: North Pacific, Mexico, Northern California coastal forests, Mojave desert, Sonoran desert

Lifespan: exact lifespan is unknown but others in the genus live 2-3 years

Diet: seeds, fruits, nuts, vegetation

Reproduction: first reproduce at 6 months old; 1 litter per year; 2-3 offspring per litter; weaned at 27 days

Peromyscus californicus, California deer mouse

California mouse

(Photo: Gabby Reynosa, SMURF intern)

Body Size: 101-127

Characteristics: yellow/gray with black flecks on back, white underside and feet, bicolor tail that is dark on top and light underneath, tail same length or longer than body

Habitat: forests, ravines, chaparral, brushy areas

Habitat (UCSC): northern martime chaparral, mixed-evergreen forest

Range: Southeastern and Coastal California

Lifespan: 16 months

Diet: acorns, seeds

Reproduction: mature at 2 months old;, breeds through the year (except winter); first reproduce at 1.5 months; may be several litters a year; 2 offspring per litter; gestate for approximately 1 month

 Peromyscus truei, Pinyon mouse

Pinyon mouse

(Photo: Gabby Reynosa, SMURF intern)

Body Size: 95-108mm

Characteristics: dorsal color can be lead colored, brownish, cinnamon, or rich tawny, separated sharply from white underparts, tail is hairy, dark on top and white on underside, ears longer than hind feet and sparsely haired, large protruding eyes, pointed nose, long whiskers, white feet

Habitat: arid foothill lowlands, seldom found above 7000 ft.; areas of pinyon and juniper where rocky slopes dominate

Habitat (UCSC): northern maritime chaparral, mixed-evergreen forest

Range: Mexico, US (NV, OK, CA, OR, NM, CO, AR, WY, TX, ID)

Lifespan: 5 years

Diet: insects, seeds, vegetation

Reproduction: first reproduce at 1 month old; 3-5 litters per year; 3-4 offspring per litter; gestate for 1 month

Reithrodontomys megalotis, Western harvest mouse

Western harvest mouse

(Photo: J.N. Stuart, Creative Commons license)

Body Size: 47-73mm

Characteristics: brown on back with grayish-white/ pale cinnamon underside, sparsely haired tail, large naked ears, longitudinal groove on each incisor

Habitat: grasslands, sagebrush, weedy waste areas, fence lines, cattail-choked marsh edges (as long as there is overhead cover)

Habitat (UCSC): grassland, coastal prairie

Range: wide range, Great Lakes to Pacific Coast, on Santa Catalina and Santa Cruz Island

Lifespan: 18 months

Diet: insects, seeds

Reproduction: breed every month of the year in some parts of its range; usually doesn’t breed for 2 months (Jan and March in CA); 4-5 litters per year

Sorex trowbridgii, Trowbridge shrew

Trowbridge shrew

(Photo: Gabby Reynosa, SMURF intern)

Body Size: 60.5-73mm

Characteristics: velvety dark gray fur with undersides almost as dark as back, slightly brownish in summer, tail sharply bicolored and dark on top, ears hidden well in hair, long abundant whiskers, feet are whitish to light tan

Habitat (range-wide): mature forests with ground litter, prefers dry ground beneath Douglas-fir but also occupies ravines, swampy woods, and areas where deep grass borders salmonberry thickets

Habitat (UCSC): redwood forest, mixed-evergreen forest

Range: along Pacific coast from Canada to Los Angeles

Lifespan: 18 months

Diet: invertebrates, seeds, vegetation

Reproduction: breeds from February to early June in Sierra Nevada;  1-2 litters per year; 4-5 offspring per litter