Animal Diversity Web U of M Museum of Zoology ADW Home ADW Home ADW Home University of Michigan Help About Aninal Names Teaching Special Topics About Us




Structured Inquiry Search — preview

Home -> Kingdom Animalia -> Phylum Chordata -> Subphylum Vertebrata -> Class Mammalia -> Order Rodentia -> Suborder Sciuromorpha -> Family Sciuridae -> Subfamily Xerinae -> Species Tamias palmeri

Tamias palmeri
Palmer's chipmunk



2008/08/31 11:21:26.330 GMT-4

By Yvonne Ybarra and Karina Zaragoza

Kingdom: Animalia
Phylum: Chordata
Subphylum: Vertebrata
Class: Mammalia
Order: Rodentia
Suborder: Sciuromorpha
Family: Sciuridae
Subfamily: Xerinae
Genus: Tamias
Species: Tamias palmeri

Geographic Range

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)

Biogeographic Regions:
nearctic (native ).

Habitat

Elevation
2100 to 3600 m
(6888 to 11808 ft)


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)

These animals are found in the following types of habitat:
temperate ; terrestrial .

Terrestrial Biomes:
chaparral ; forest ; mountains .

Physical Description

Mass
50 to 69.40 g
(1.76 to 2.44 oz)


Length
210 to 223 mm
(8.27 to 8.78 in)


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)

Some key physical features:
endothermic ; heterothermic ; homoiothermic; bilateral symmetry .

Sexual dimorphism: female larger.

Reproduction

Breeding interval
These animals breed once per year.

Breeding season
Breeding occurs in March.

Number of offspring
3 to 6

Gestation period
30 to 33 days

Time to weaning
5 weeks (average)

Age at sexual or reproductive maturity (female)
10 months (average)

Age at sexual or reproductive maturity (male)
10 months (average)

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. (Hirshfeld, 1975; Nevada Department of Wildlife, 2005; Ruff, 1999; White, 1953)

Key reproductive features:
iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization ; viviparous .

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)

Parental investment:
altricial ; pre-fertilization (provisioning, protecting: female); pre-hatching/birth (provisioning: female, protecting: female); pre-weaning/fledging (provisioning: female, protecting: female); pre-independence (provisioning: female, protecting: female).

Lifespan/Longevity

Typical lifespan (wild)


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)

Behavior

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)

Home Range

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)

Key behaviors:
terricolous; diurnal ; motile ; sedentary ; hibernation ; solitary ; territorial .

Communication and Perception

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)

Communicates with:
visual ; tactile ; acoustic .

Perception channels:
visual ; tactile ; acoustic ; chemical .

Food Habits

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)

Primary Diet:
omnivore .

Animal Foods:
mammals; eggs; insects.

Plant Foods:
leaves; seeds, grains, and nuts; fruit.

Other Foods:
fungus.

Foraging Behaviors:
stores or caches food .

Predation

Known predators

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. (Nargorsen et al., 1995; Nevada Department of Wildlife, 2005)

Anti-predator adaptations::
cryptic .

Ecosystem Roles

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. (Nargorsen et al., 1995)

Key ways these animals impact their ecosystem:
disperses seeds.

Economic Importance for Humans: Negative

These animals have no reported negative impact on humans.

Economic Importance for Humans: Positive

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.

Conservation Status

IUCN Red List: [link]:
Vulnerable.

US Federal List: [link]:
No special status.

CITES: [link]:
No special status.

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. (Nargorsen et al., 1995; Nevada Department of Wildlife, 2005)

Contributors

Yvonne Ybarra (author), California State Polytechnic University, Pomona. Karina Zaragoza (author), California State Polytechnic University, Pomona.
John Demboski (editor), California State Polytechnic University, Pomona.

Nancy Shefferly (editor), Animal Diversity Web Staff.

References

Best, T. 1993. Tamias palmeri. Mammalian Species, 443: 1-6.

Hirshfeld, J. 1975. Reprodution, Growth, and Development of Two Species of Chipmunk: Eutamias panamintinus and Eutamias palmeri. University of Nevada, Las Vegas: University of Nevada.

Hafner, D., E. Yensen, G. Kirkland, J. Hall, J. Cook, D. Nargorsen. 1995. "Chipmunks" (On-line). Accessed November 16, 2005 at http://www.iucn.org.

Nevada Department of Wildlife, 2005. "In the Wild Animals of Nevada" (On-line). Nevada Department of Wildlife. Accessed October 19, 2005 at http://www.ndow.org.

Ruff, S. 1999. Palmer's chipmunk| Tamias palmeri. Pp. 372-373 in D.E. Wilson, S. Ruff, eds. The Smithsonian Book of North American Mammals. Washington: The Smithsonian Institution Press in Association with the American Society of Mammalogists.

White, J. 1953. The Baculum in the Chipmunks of Western North America. University of Kansas Publication, Museum of Natural History: University of Kansas.

Wilson, D., S. Ruff. 1999. The Smithsonian Book of North American Mammals. Washington: The Smithsonian Institution Press in Association with the American Society of Mammalogists.

2008/08/31 11:21:29.039 GMT-4

To cite this page: Ybarra, Y. and K. Zaragoza. 2006. "Tamias palmeri" (On-line), Animal Diversity Web. Accessed September 07, 2008 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Tamias_palmeri.html.

Disclaimer: The Animal Diversity Web is an educational resource written largely by and for college students. ADW doesn't cover all species in the world, nor does it include all the latest scientific information about organisms we describe. Though we edit our accounts for accuracy, we cannot guarantee all information in those accounts. While ADW staff and contributors provide references to books and websites that we believe are reputable, we cannot necessarily endorse the contents of references beyond our control.

Other formats: OWL

Home  ¦  About Us  ¦  Special Topics  ¦  Teaching  ¦  About Animal Names  ¦  Help

Structured Inquiry Search — preview