Tamias palmeri
Palmer's chipmunk

Palmer's chipmunks, Tamias palmeri, are found solely in the state of Nevada. This species is restricted to the Spring Mountains west of Las Vegas. (Hirshfeld, 1975; Ruff, 1999)

Palmer’s chipmunks are found at elevations between 2,100 and 3,600 m in the Spring Mountains. They are most abundant between 2,400 and 2,550 m. Tamias palmeri is commonly found in coniferous forests that contain juniper-piñon pine, fir-pine, and bristlecone pine communities. In the Spring Mountains, Panamint chipmunks, Tamias panamintinus, inhabit lower elevation forests. (Hirshfeld, 1975; Nevada Department of Wildlife, 2005)

The total body length varies from 210 to 223 mm. The tail measures between 86.5 and 101.5 mm. The body weight ranges from 50 to 69.4 g. (Ruff, 1999)

Adults have distinct solid black and solid white dorsal stripes like other chipmunks, with the sides of the body tawny and tan. The ventral surface of the tail is much paler. The top of the head and rump are gray.

Tamias palmeri exhibits a narrow and flattened brain case, long upper incisors, larger cheek teeth and nearly parallel zygomatic arches. The length of the baculum is approximately 4 mm. Baculum size can be used to distinguish between T. palmeri from T. panamintinus, which has a baculum approximately 3 mm long. (; Best, 1993; Hirshfeld, 1975; White, 1953)

These animals appear to hibernate facultatively. Although they may dwell in their underground burrows when weather is cold, on warm winter days they are often seen running around on top of the snow. They may enter torpid states when it is cold, but wake often to snack on cached food. We assume here that they are homoiothermic and heterothermic, in that they maintain a constant body temperature which is dependent upon whether they are active or torpid. (Hirshfeld, 1975; Ruff, 1999)

The mating system of these animals has not been reported. However, other chipmunks tend to be polygynous. Tamias palmeri may be similar. (Hirshfeld, 1975; Ruff, 1999)

Palmer’s chipmunks are reproductively active from April through July. Mating occurs during March, when males exhibit scrotal testes. Gestation is between 30 and 33 days. The average number of embryos per litter ranges between 3 and 6.

Hairless young are born underground during mid-summer and are weaned by August. They usually appear above ground at the end of July, or around the age of 5 weeks, and are able to eat nuts, seeds, and berries within a week of their emergence from the natal burrow.

Like other chipmunks, these animals are capable of breeding in the season following their birth. Young are independent by the end of summer. (Nevada Department of Wildlife, 2005; Hirshfeld, 1975; Ruff, 1999; White, 1953)

Because chipmunks rear their young in burrows, little is known about their parental care. However, in most species in the genus, males play no role in parental care. Females nurse, groom, and protect the young in the natal burrow. Although hairless and helpless at birth, these animals develop rapidly and are generally independent by the end of the summer. (Best, 1993; Hirshfeld, 1975; Ruff, 1999)

Depending on food availability, weather conditions and predator/prey situations, the lifespan of T. palmeri is between one to four years. (Nevada Department of Wildlife, 2005; Nevada Department of Wildlife, 2005)

Palmer's chipmunks are diurnal, ground-dwelling mammals. They sometimes occupy nests in trees, but these are not common. Foraging occurs along the floors of canyons and rocky outcroppings.

These animals can show extreme aggression and territoriality, especially during the breeding season.

Hibernation typically occurs, although it consists of bouts of torpor interspersed with active times when weather permits. These small mammals cache food to eat during winter. (Hirshfeld, 1975; Ruff, 1999)

They usually live on the ground, in rock crevices or fallen logs. Within their home ranges, they dig burrows that can be up to 30 feet in length. Further information on home range size is not available, although most chipmunks inhabit areas of less than one hectare. (Hirshfeld, 1975)

The name chipmunk is derived from the chipping noises these animals make with their teeth. Loud trilling type noises are used to call to potential mates, as well as in defending territories.

In addition to vocal communication, most species of chipmunk use visual cues, such as body posture and tail positioning, in communicating with other members of their species. Tactile communication is likely to figure prominently in maternal interactions with young, as well as in mating. The role of chemical communication has not been described in these animals. (Wilson and Ruff, 1999)

Palmer's chipmunks are omnivorous. Their diet includes seeds, fruits, various plants, fungus, and invertebrates such as worms, snails and insect larvae. Bird eggs and small mice are occasionally eaten. From spring through autumn, the diet consists mainly of seeds, fruits, greens and flowers. Invertebrates are not part of the diet during spring, but may be found in other seasons.

In the autumn, Palmer's chipmunks gather and store food to be used during winter. (Hirshfeld, 1975; Ruff, 1999)

Palmer’s chipmunks may be eaten by carnivores such as coyotes, fox, weasels, and raccoons. Feral dogs and cats may also prey upon them. Other predators include birds of prey and snakes. (Hafner, et al., 1995; Nevada Department of Wildlife, 2005)

Tamias palmeri plays an important role in the food chain. It also helps in seed dispersal for various forms of plants. These chipmunks have a symbiotic relationship with mychorrizal fungi. (Hafner, et al., 1995)

These animals have a very restricted range, and do not often come in contact with humans. As such, it is unlikely that they have any positive impact on human economies.

These animals have no reported negative impact on humans.

Palmer’s chipmunks are not endangered, but the species is listed as a population of concern in Nevada. Since this species is restricted to the Spring Mountains, human impact due to habitat loss and increasing recreational activity is of potential concern. IUCN lists these animals as vulnerable. (Hafner, et al., 1995; Nevada Department of Wildlife, 2005)