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Palmer’s Chipmunk

Tamias palmeri

French: Tamia de Palmer / German: PalmerBackenhornchen / Spanish: Ardilla listada de Palmer

Taxonomy. Eutamias palmeri Merriam, 1897,

“Charleston Peak,”

Clark County, Nevada, USA.

This species is monotypic.

Distribution. Spring Mts, Clark County, S Nevada (USA).

Descriptive notes. Head-body 125-5-126-6 mm, tail 80-3-98 mm; weight 52-4-59-7 g. Palmer’s Chipmunk has an overall dark brown coloration, and can be differentiated from the Panamint Chipmunk (7. panamintinus), which is the only sympatric species of Tamias, by the larger size of Palmer’s Chipmunk, grayer shoulders, browner body, and paler venter. Chromosome number of Palmer’s Chipmunk is 2n = 38. Karyotype is type B for Tamias and consists of five pairs of metacentric autosomes, six pairs of

submetacentric autosomes, seven pairs of acrocentric autosomes, a submetacentric X chromosome, and an acrocentric Y chromosome.

Habitat. Forest vegetation at ¢.2100-3600 m, although more common at c.2400-2550 m. Palmer’s Chipmunk is found in association with several members of Pinaceae: white fir—ponderosa pine stands (Abies concolor, Pinus ponderosa), bristlecone pine (P. aristata); it is also found in

stands of single leaf pinyon pine (P. monophylla) and Utah juniper (Juniperus osteosperma, Cupressaceae) and mountain mahogany—manzanita stands (Cercocarpus ledifolius, Rosaceae; Arctostaphylos pungens, Ericaceae). Palmer’s Chipmunk has a preference for rock outcrops, crevices, caves or fallen logs.

Food and Feeding. Diet of Palmer’s Chipmunk consists mostly of conifer seeds and fruits, but also includes fungi, bark, lichens, leaves, flowers, and arthropods.

Breeding. Breeding season occurs from April to May, with parturition occurring between May to June. Gestation is estimated to last ¢.33 days or more, and average litter size is c.4, with a range of 3-6. Availability of free water appears to increase its reproductive success.

Activity patterns. Palmer’s Chipmunk is terrestrial, diurnal, and active year-round, although activity nearly ceases during winter. Males can forage during winter when weather is mild, though there may still be snow on the ground. A secretive but easily tamed species; males are more aggressive than females. Its vocalization is described as “chips,” with 5-17 calls per five seconds. Female vocalizations have a higher maximum frequency. Other less common calls are described as “chucks,” “chippering,” and growls.

Movements, Home range and Social organization. There is no information available for this species.

Status and Conservation. Classified as Endangered on The IUCN Red List. The current population trend is decreasing. Water diversion projects and land conversion in its distribution are reducing available riparian habitat. Urban sprawl is also removing suitable habitat within the distribution of Palmer’s Chipmunk, and increasing predation pressure from feral domestic cats (Felis catus). Lack of information on Palmer's Chipmunk may impair conservation efforts.

Bibliography. Best (1993f), Best, Clawson & Clawson (1994a), Davis et al. (2008), Gannon & Stanley (1991), Lowrey et al. (2008), Thorington et al. (2012).