Chipmunk
| Chipmunk | ||||||||||||
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Chipmunk ( Tamias alpinus ) |
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| Scientific name | ||||||||||||
| Tamias alpinus | ||||||||||||
| Merriam , 1893 |
The mountain chipmunk ( Tamias alpinus , syn .: Neotamias alpinus ) is a type of squirrel from the genus of the chipmunk ( Tamias ). It occurs exclusively in the high elevations of the Sierra Nevada Mountains in California in the United States .
features
The rock chipmunk reaches an average head-trunk length of about 10.5 centimeters, the tail is about 6.9 to 7.5 centimeters long and the weight is about 35 grams. The fur of the animals is light pale orange to sand-colored and there are four white stripes on the back, which are delimited by pale brown stripes. Compared to most other chipmunks, the mountain chipmunk is very small; among the sympatric species, only the small chipmunk ( Tamias minimus ) corresponds to it in size . The mountain chipmunk differs from this by its shorter tail, larger ears and somewhat longer skull.
distribution
The chipmunk is found exclusively in the high altitudes of the Sierra Nevada from Tuolumne County to Tulare County in California in the United States . The altitude distribution ranges from 2300 to 3900 meters.
Way of life
The mountain chipmunk lives at altitudes of up to 3900 meters in the Sierra Nevada and occurs there spotty, especially in mountain meadows, valley meadows, scree, open stands of coastal pine ( Pinus contorta ) and smaller stands of white-stemmed pine ( Pinus albicaulis ). The occurrence seems to be strongly tied to these habitats and the animals spend a lot of time in the open scree and other rocky habitats. The habitats are very dry and exposed to direct sunlight, but usually never reach temperatures of more than 20 ° C.
The species is diurnal and ground living, but can also climb trees and rocks. It is predominantly herbivorous and feeds primarily on the seeds of grasses, herbs and sedges, and more rarely also on pine seeds. The animals collect seeds in their cheek pouches and transport them to protected areas under bushes or rocks to eat. In investigations up to 5000 seeds were found in the cheek pouches of a single individual. They also set up camps under rocks and in crevices. In addition, it is assumed that they also prey bird eggs and nestlings and thus limit the breeding area of the rose-bellied snow beak ( Leucosticte arctoa ) imported from Asia . The range of the mountain chipmunk overlaps with that of five other species of the genus, but it only lives sympatricly with the lodgepole chipmunk ( Tamias speciosus ). This somewhat larger, more aggressive species, which is more competitive in lower elevations and denser vegetation, limits the spread of the mountain chipmunk into the lower elevations. The mountain chipmunk is territorial and defends its territory against conspecifics through more aggressive communication behavior with different tones, ranging from high-pitched whistles to deeper "chucks" and "chips", and tail positions. From October the animals begin their hibernation and they leave their burrows again in June when there is still snow in their habitat.
So far, no nests have been documented for the mountain chipmunk. In early summer the young are born in litters of four to five animals, these leave the burrows at the end of July and beginning of August and are fully grown by October. Predators are not known, but the ermine ( Mustela erminea ) appears as a potential predator in the lifelong dream . Two types of animal lice ( Neohaematopinus pacificus , Haplopleura arboricola ) and the mite Ornithonyssus sylvarium have been documented as parasites .
Systematics
The mountain chipmunk is classified as an independent species within the genus of chipmunks ( Tamias ), which consists of 25 species. The first scientific description comes from Clinton Hart Merriam from 1893, who described the species on the basis of individuals from the region south of Mount Whitney in Tulare County , California, from an altitude of 3,050 meters. Within the chipmunk group, the mountain chipmunk, together with most other species, is assigned to the subgenus Neotamias , which is also discussed as an independent genus.
Apart from the nominate form, no subspecies are distinguished within the species .
Status, threat and protection
The mountain chipmunk is classified by the International Union for Conservation of Nature and Natural Resources (IUCN) as "least concern", although the range covers less than 20,000 km 2 . This is justified with the regular occurrence, there are no potential risks to the existence of the company.
supporting documents
- ↑ a b c d e f g h i j Richard W. Thorington Jr. , John L. Koprowski, Michael A. Steele: Squirrels of the World. Johns Hopkins University Press, Baltimore MD 2012; Pp. 315-316. ISBN 978-1-4214-0469-1
- ↑ a b c Neotamias alpinus in the IUCN Red List of Threatened Species 2015.3. Listed by: AV Linzey & NatureServe (G. Hammerson), 2008. Retrieved November 26, 2015.
- ↑ a b Tamias alpinus In: Don E. Wilson , DeeAnn M. Reeder (Ed.): Mammal Species of the World. A taxonomic and geographic Reference. 2 volumes. 3. Edition. Johns Hopkins University Press, Baltimore MD 2005, ISBN 0-8018-8221-4 .
- ↑ Bruce D. Patterson, Ryan W. Norris: Towards a uniform nomenclature for ground squirrels: the status of the Holarctic chipmunks. Mammalia 80 (3), May 2016; Pp. 241-251 doi : 10.1515 / mammalia-2015-0004
literature
- Richard W. Thorington Jr. , John L. Koprowski, Michael A. Steele: Squirrels of the World. Johns Hopkins University Press, Baltimore MD 2012; Pp. 315-316. ISBN 978-1-4214-0469-1
Web links
- Neotamias alpinus inthe IUCN Red List of Threatened Species 2015.3. Listed by: AV Linzey & NatureServe (G. Hammerson), 2008. Retrieved November 26, 2015.