The range of Tamias speciosus is contained primarily within California. Populations occupy the eastern side of the Sierra Nevada, and in southern California, the disjunct San Bernardino, San Jacinto, and San Gabriel mountains. Lodgepole chipmunks extend as far north as Toulume and Nevada Counties, with unconfirmed presence further north. The species in also found in the Lake Tahoe region of California and Nevada. (Best, et al., 1994; Chappell, 1978; Heller and Gates, 1971; Heller, 1971; Ingles, 1965; Meyer, et al., 2005; Sharples, 1983; Sutton, 1995; White, 1953)
Lodgepole chipmunks are found in subalpine mixed conifir forests containing lodgepole pine, red fir, and Jeffery pine. Other woodland vegetation includes white fir, Douglas fir, ponderosa pine, sugar pine, incense cedar, and California black oak. Tamias speciosus typically occurs at elevations between 1,500 and 3,300 m, with the greatest density of populations occuring between 2,400 and 3,000 m. (Best, et al., 1994; Chappell, 1978; Heller, 1971)
Tamias speciosus is a small sciurid, typically weighing between 50 and 70 g. These animals measure from 197 to 212 mm in length. Tail length is reported at 13 to 22 mm. As in other chipmunks, females are slightly larger than males.
Tamias speciosus is a brightly colored, medium-sized chipmunk compared to others of the genus. It is easily distinguished from sympatric and parapatric relatives by its remarkably prominent facial and dorsal stripes. The dark cheek and submolar facial stripes are blacker with some brown and broader than in other neighboring species. The submolar stripes extend from the rostrum to the ear and are central below the eyes. The dark dorsal stripes strongly contrast with the light dorsal stripes. The black median stripe may fade to brown across the shoulder area. The white medial stripes are slightly yellow, whereas the white lateral stripes are much brighter and more prominent. These chipmunks nearly to completely lack a dark outer lateral stripe. The crown of the head is usually brown and sprinkled with grey. The sides of the head can be yellowish-tawny to brown in the summer. There is a white patch behind the ears, and the underside of the tail is cinnamon through most of the length with black near the tip.
The incisors of lodgepole chipmunks are short and straight, helping to distinguish these chipmunks from other species in the area. The dental formula of T. speciosus is 1-0-2-3/1-0-1-3.
In areas of sympatry, the size and shape of genital bones may provide the most diagnostic features of these animals. The baculum is 2.1 to 3.2 mm in length and the distal 2/3 of the shaft is strongly compressed.
Molecular differences with related species may be used in identification, since T. speciosus is sometimes confused with Tamias amoenus based solely on morphological diagnostics. (Best, et al., 1994; Good, et al., 2003; Ingles, 1965; Merriam, 1893; Sutton, 1995; White, 1953)
Chipmunks are endothermic hibernators. Their body temperature changes seasonally, so they can be considered heterothermic. However, since individuals maintain a constant body temperature in any given season, they can also be called homoiothermic. (Best, et al., 1994; Sutton, 1995)
When males are ready to mate, the scrotum is black and the testes are in a pendulous position. Both females and males use chattering vocalization and visual cues to attract mates, such as flipping their tails and using various body postures.
Although data on the mating system of this species are not available, most members of the genus Tamias for which mating systems have been described are polygynous. It is likely that T. speciosus is similar. (Best, et al., 1994)
Tamias speciosus breeds during May and early June. The gestation period is about one month, after which a litter of 3 to 6 pups is born. Young chipmunks are typically poorly developed at birth. Lactation lasts for 1 month. Young are independent shortly after weaning, and typically disperse in the autumn of their birth year. These chipmunks reach reproductive maturity the following spring. (Best, et al., 1994)
Young are born in spring or early summer. Mothers lactate for about a month, at which time they stop caring for their young. Males are not known to provide any parental care in this species. (Best, et al., 1994)
Not much is known about T. speciosus lifespan. Individuals of this species are usually expected to only live through one breeding season, which is about a year. Mortality may be due to predation or to low temperatures, as many of these chipmunks are thought to freeze to death.
In spite of low average lifespan, individuals may live for up to 4 years in the wild and 5 years in captivity. (Best, et al., 1994)
Field studies of interspecific aggression indicate that T. speciosus is aggressive to its sympatric and parapatric relatives, whereas in laboratory studies T. speciosus tends to be subordinate to other members of the genus. Both field and laboratory studies indicate high intraspecific aggression.
Tamias speciosus is diurnal and undergoes hibernation during the winter months until about March or early April. These chipmunks are somewhat arboreal, but spend much of their time on the ground gathering and caching food, especially in summer and autumn. (Best, et al., 1994; Chappell, 1978; Heller, 1971)
Lodgepole chipmunks use a small repertoire of vocalizations to communicate. These include a high “whisk”, a shrill “tsew”, a rapid “pst-pst-pst-a-ku”, a chip, a chippering, a chuck, and a whistle. In courtship, T. speciosus uses a chattering vocalization and visual cues. Tail flipping and various body postures are used during courtship, inter- and intra-specific aggression, and during encounters with potential predators.
Although not specifically reported, we may assume that tactile communication occurs during mating, as well as between mothers and their young. (Best, et al., 1994)
Lodgepole chipmunks are omnivorous, eating a wide range of seeds, nuts, berries and insects. They also eat other arthropods, fungi, and small vertebrates. Tamias speciosus individuals consume leaves, flowers, pollen, fruit, and garbage, when such items are available. They are known to be great robbers of eggs from bird nests, and they cache food. (Best, et al., 1994; Chappell, 1978; Meyer, et al., 2005; Pyare and Longland, 2001)
Tamias speciosus consumes truffles of ectomycorrhizal fungi. These fungi aid forest ecosystems by increasing their water and nutrient uptake and by facilitating forest succession. Tamias speciosus plays a major role in the health and succession of forest ecosystems by dispersing viable fungal spores to new patches as well as being important seed and pollen dispersers.
Humans profit from the lodgepole chipmunks through their effects on their ecosystem. Tamias speciosus keeps down pests that could harm plants and other organisms. They have a mutualism with ecotomycorrhizal fungi and with many plant species for which they disperse seeds. Tamias speciosus also provides enjoyment for humans who view them in nature. There may be some economic value in breeding these animals for the pet trade. (Townsend, et al., 2003)
Tamias speciosus is known to be a host for Yersinia pestis (plague) and for various ectoparasites, such as fleas, ticks, and lice. Besides plague, these parasitic organisms can harbor potentially dangerous diseases such as rabies. There is a direct economic cost when humans must be treated for these diseases. (Best, et al., 1994; Townsend, et al., 2003)
According to most sources, T. speciosus has no special conservation status. IUCN lists this species as a lower risk animal. In spite of this, it is important to maintain their habitat to assure that the species is maintained in the future.
Vivian Quesada (author), California State Polytechnic University, Pomona, Amy Chambers (author), California State Polytechnic University, Pomona, John Demboski (editor, instructor), California State Polytechnic University, Pomona.
Nancy Shefferly (editor), Animal Diversity Web.
living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.
uses sound to communicate
young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.
Referring to an animal that lives in trees; tree-climbing.
having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.
an animal which directly causes disease in humans. For example, diseases caused by infection of filarial nematodes (elephantiasis and river blindness).
uses smells or other chemicals to communicate
having markings, coloration, shapes, or other features that cause an animal to be camouflaged in its natural environment; being difficult to see or otherwise detect.
animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.
union of egg and spermatozoan
A substance that provides both nutrients and energy to a living thing.
forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.
having a body temperature that fluctuates with that of the immediate environment; having no mechanism or a poorly developed mechanism for regulating internal body temperature.
the state that some animals enter during winter in which normal physiological processes are significantly reduced, thus lowering the animal's energy requirements. The act or condition of passing winter in a torpid or resting state, typically involving the abandonment of homoiothermy in mammals.
offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).
having the capacity to move from one place to another.
This terrestrial biome includes summits of high mountains, either without vegetation or covered by low, tundra-like vegetation.
the area in which the animal is naturally found, the region in which it is endemic.
an animal that mainly eats all kinds of things, including plants and animals
the business of buying and selling animals for people to keep in their homes as pets.
breeding is confined to a particular season
remains in the same area
reproduction that includes combining the genetic contribution of two individuals, a male and a female
places a food item in a special place to be eaten later. Also called "hoarding"
uses touch to communicate
that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).
Living on the ground.
defends an area within the home range, occupied by a single animals or group of animals of the same species and held through overt defense, display, or advertisement
uses sight to communicate
reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.
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