Mice, Rats, Lemmings, and Voles (Family Cricetidae)
Western Harvest Mouse,Reithrodontomys megalotis. Head and body 2.8–3 in (7.1–7.6 cm), tail 2.3–3.2 in (5.8–8.1 cm); upper parts and sides buffy, underparts grayish brown; tail indistinctly bicolored; no external cheek pouches. Western Harvest Mice have been reported up to 6,700 ft (2,040 m) in the White Mountains, inhabiting damp grassy meadows and marshy areas, but they may occur in other habitats during population peaks. They eat mainly seeds and fruits, with some insects, and they are preyed upon by owls, snakes, and a number of mammalian predators. They commonly use the runways of meadow mice (Microtus spp.) during their nightly foraging periods. Litters are produced several times per year and average four to six young.
Deer Mice,Peromyscus. There are three species of Deer Mice present in the White Mountains. They can be distinguished from other mice by several characteristics, including their large, membranous ears, lack of external cheek pouches, and a tail exceeding 70% of the head and body length. Their diets consist of seeds, fruits, and insects, particularly butterfly and moth larvae. They are active year-round and store caches of food for winter consumption. Deer Mice are preyed upon by many avian and mammalian predators.
Pinyon Mouse, P. truei . Head and body 3.6–4 in (9.1–10.2 cm), tail 3.4–4.8 in (8.6–12.2 cm); brown to dark brown above, creamy white underneath; feet whitish; tail bicolored, whitish below, length exceeds 90% of head and body length; ears very large. Pinyon Mice have been documented up to 9,500 ft (2,896 m) and are common in the Pinyon-juniper Woodland, where they feed on juniper berries and Pinyon Pine nuts. Much of their time is spent in trees.
Deer Mouse, P. maniculatis . (Fig. 12.14) Head and body 2.8–4 in (7.1–10.2 cm), tail 2–5 in (5–12.7 cm); yellowish brown to grayish above, pure white below; feet white; bicolored tail usually less than 90% of head and body length. The Deer Mouse, probably the most common mammal in North America, has the greatest elevational range of any mammal in California. The same subspecies of Deer Mouse that lives on the floor of Death Valley also occurs on White Mountain Peak (14,246 ft, 4,340 m). Deer Mice live in nearly all habitat types.
Figure 12.14
Deer Mouse.
Canyon Mouse, P. crinitus . Head and body 3–3.4 in (7.6–8.6 cm), tail 3.5–4.3 in (8.9–10.9 cm). Fur long and soft, pale yellowish buff above and creamy white below; long hairs on tip of tail; feet white; tail usually longer than the head and body, with a broad, light brown dorsal stripe, creamy white below. Canyon Mice frequent rocky areas up to 8,250 ft (2,515 m) in the White Mountains.
Southern Grasshopper Mouse,Onychomys torridus. Head and body 3.5–4 in (8.9–10.2 cm), tail 1.6–2 in (4–5 cm); light cinnamon above, white below. The Grasshopper Mouse has been found up to 5,000 ft (1,524 m), most commonly in canyons. The diet is 90% animal matter, most of which is arthropods. These nocturnal rodents emit high–pitched calls and usually nest in burrows dug by other mammals. Predators include snakes, weasels, owls, Bobcats, and other carnivores.
Wood Rats,Neotoma. The scaly tail of the largely nocturnal Wood Rat is covered by overlying hairs. Wood Rats eat mostly vegetation and are preyed upon by Coyotes, foxes, owls and large snakes. Litter size is three to four, and young are born in the spring. There are two species of wood rats present in the White Mountains.
Desert Wood Rat, N. lepida . Head and body 5.8–7 in (14.7–17.8 cm), tail 4.3–6.4 in (10.9–16.3 cm); fur grayish, mixed with black hairs above, underparts white or buffy; tail hairs short. Also known as the Pack Rat, this species occurs up to 8,000 ft (2,440 m) in Sagebrush Scrub and Pinyon-juniper Woodland and frequents rocky areas in these regions. It uses cactus for water and nesting material.
Bushy-tailed Wood Rat, N. cinerea . (Fig. 12.15) Head and body 7–9.4 in (17.8–23.9 cm), tail 5.2–7.4 in (13.2–18.8 cm); fur cinnamon brown to buffy, some tipped with black above; white or grayish below; tail with hairs over 2 cm long. Bushy-tailed Wood Rats have been recorded up to 10,300 ft (3,140 m) in the White Mountains; however, a single individual was collected from the summit hut on White Mountain Peak (14,246 ft, 4,340 m) during the summer of 1983. Whether this is an accurate representation of their usual range in these mountains is uncertain.
Figure 12.15
Bushy-tailed Wood Rat.
Sagebrush Vole,Lagurus curtatus. Head and body 3.8–4.5 in (9.6–11.4 cm), tail 0.6–1.1 in (1.5–2.8 cm); fur long and fine, light grayish above and almost white below. Sagebrush Voles occur up to 12,500 ft (3,810 m) in Sagebrush Scrub and Pinyon-juniper Woodland. Similar to meadow voles, they are active both day and night. They feed on nearly anything green and do not require additional drinking water. This species is endemic to the Great Basin. Litters average five young.
Meadow voles,Microtus. There are three species of meadow mice or voles in the White Mountains. All are active both day and night and are preyed upon by hawks, owls, falcons, Coyotes, weasels, and snakes. They feed on stems and leaves of forbs and grasses. The litter size usually ranges from five to eight young.
Montane Vole, M. montanus . Head and body 4–5.5 in. (10.2–14 cm), tail 1.2–2.6 in (3–6.6 cm); fur dark brown, some reddish tinged; undersurface dark gray; tail usually less than one-third of total body length, nearly unicolored. The Montane Vole occurs up to at least 12,500 ft (3,810 m), commonly in alpine meadows or other high-elevation grassy areas. It builds conspicuous runways through grasses and sedges, and it tunnels beneath the snow during the winter. It feeds chiefly on succulent stems and leaves of forbs, rarely grasses.
Long-tailed Meadow Vole, M. longicaudus . (Fig. 12.16) Head and body 4.5–5.3 in (11.4–13.5 cm), tail 2–3.5 in (5–8.9 cm); dorsal band of reddish brown fur with grayish sides and bluish gray underparts; tail usually more than one-third of total body length and more or less bicolored. The Long-tailed Meadow Vole is common along streams and in wet meadows in higher elevations up to 11,500 ft (3,510 m). Unlike the Montane Vole, it does not construct extensive runways.
California Meadow Vole, M. californicus . Head and body 4.6–5.7 in (11.7–14.5 cm), tail 1.6–2.8 in (4–7.1 cm); buffy or dark brown above, commonly with a reddish tinge on the middle of the back; undersurface blue-gray to white; ears project well above fur. This species has been recorded up to 4,500 ft (1,370 m) in Silver Canyon, but occurs mostly along the Owens River.
Figure 12.16
Long-tailed Meadow Vole.