Yellow spruce chipmunk
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Yellow spruce chipmunk ( Tamias amoenus ) |
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| Tamias amoenus | ||||||||||||
| JA Allen , 1890 |
The yellow pine chipmunks ( Tamias amoenus ), also Yellow spruce Chipmunk is a Hörnchenart from the kind of chipmunks ( Tamias ). It occurs in northwestern North America from southwestern Canada to the northwestern United States .
features
The yellow spruce chipmunk reaches an average head-trunk length of about 11.9 to 12.3 centimeters, the tail is slightly shorter with a length of 8.6 to 9.5 centimeters. The weight of the animals is around 43 to 60 grams. The fur is reddish-brown and appears dark, on the back there are five dark, usually black, back stripes that are separated by lighter stripes. The light stripes towards the middle of the body are rather grayish, the outer ones are white. The stripe pattern can also be found in the facial drawing. The ventral side is usually light creamy white to white.
distribution
The yellow spruce chipmunk is found in northwestern North America from southwestern Canada to the northwestern United States . The distribution area extends from central British Columbia and southwest Alberta in Canada to northern California , eastern to central Montana and northwest Wyoming . They are also found in Washington , Idaho , Nevada and Oregon .
Way of life
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The yellow spruce chipmunk lives mainly in the drier forest areas and zones in the transition area to the boreal zone of the Canadian west. In the southern areas of the distribution area, the species occurs at different altitudes up to heights of 3000 meters. She prefers grass steppe and pasture areas with a vegetation of grass, herbs and sedges as well as open stands of Jeffrey pines ( Pinus jeffreyi ) or coastal pine ( Pinus contorta ). The animals are adaptable; due to their preference for open areas, they occur more frequently in felled forests , succession areas and secondary forest areas than in primary forest areas.
The species is diurnal and living on the ground, but the animals can also climb into the trees and rocks. They are predominantly herbivorous and feed mainly on the seeds of grasses, herbs and other vegetation, but also use other parts of plants such as flowers and roots as well as mushrooms, insects and bird eggs as an additional source of food. They also feed on fungi that live underground and are probably an important spore distributor for them . The animals collect the seeds and lay camps for hibernation . They also buried individual seed and thus ensure the dissemination of different plant species, about Purshia tridentata that the castanopsis belonging Casternopsis sempervirens and the otherwise spread by the wind Jeffrey pine and sugar pine ( Pinus lambertiana ). Especially in times when there is little food available, the animals concentrate more on foraging, at the same time they may reduce their vigilance towards predators, which can lead to higher mortality rates . The species reacts aggressively towards representatives of other chipmunk species, whereby they are usually subject to competition with the Townsend chipmunks ( Tamias townsendii ) and are dominant compared to the small chipmunks ( Tamias minimus ). This inter-species competition is likely to determine the occurrence of the species in different regions and altitudes.
The population density of the animals is 1.25 to 7 individuals per hectare, regionally depending on the availability of suitable habitats and other factors. In the cold winter, the animals hibernate . The animals usually lay their nests underground under tree stumps, piles of wood and rocks; more rarely, above-ground grass nests are found in the vegetation. The wake-up phase and the beginning of spring activity begins in April and the mating season is in early May. The animals are promiscuous and both sexes have several sex partners in a mating period. The mating rate of closely related animals is likely to be low. After about a month of gestation, the females give birth to an average of four to five pups.
The most important predators of the animals include various birds of prey as well as mammals such as foxes and coyotes . Known ectoparasites include bot flies (genus Cuterebra ) and at least seven documented species of fleas .
Systematics
The yellow spruce chipmunk is classified as an independent species within the genus of chipmunks ( Tamias ), which consists of 25 species. The first scientific description comes from Joel Asaph Allen from 1890, who introduced the species on the basis of individuals from Fort Klamath in Klamath County , Oregon. The type specimen came from the collection of Clinton Hart Merriam and was collected by JH Merrill. With a few other species, the yellow spruce chipmunk was classified in the subgenus and partly also in the genus Neotamias .
Within the species, 14 subspecies are distinguished , including the nominate form :
- Tamias amoenus amoenus : nominate form. It occurs in the zones of the boreal coniferous forest from northern California to central northern Oregon and Washington. The five dark back stripes are very clearly recognizable and have reddish speckles. The inner two light stripes are mottled, the outer two white. The head is gray, reddish and black. The ear mark is black
- Tamias amoenus affinis : occurs in Canada in southern British Columbia. The shape corresponds to the nominate shape in its appearance.
- Tamias amoenus albiventris : the type locality is in the border area of Asotin County and Garfield County in Washington state. The top of the animals is greyish, the underside white to creamy white. The inner light stripes are smoky gray, the outer whitish gray.
- Tamias amoenus canicaudus : in eastern Washington. The tail is edged gray, the basic color of the back is greyish wine-red and the dark stripes are relatively wide.
- Tamias amoenus caurinus : in the Olympic Mountains in Washington to the limits of the forest zones. The shape corresponds to the nominate shape, but is darker. The ear marks are small, the dark back stripes are black.
- Tamias amoenus celeris : in the Pine Forest Mountains in Humboldt County , Nevada. The shape is small and paler in color, it corresponds to Tamias amoenus monoensis .
- Tamias amoenus cratericus : in Butte County , Idaho. The shape is dull gray in the basic color and the light stripes are all smoky gray, with the outer ones being somewhat lighter.
- Tamias amoenus felix : In the Mount Baker Range in British Columbia. On the sides of the body, the cheeks and on the underside of the tail, the coloration shows a clear ocher wash. The dark back stripes are broad, the underside has a rust-brown tone.
- Tamias amoenus ludibundus : in Canada in the border region of Alberta and British Columbia. It is the largest subspecies, the sides of the body are dark and sandy yellow, the underside is yellowish.
- Tamias amoenus luteiventris : in the border regions between Alberta and Montana and Wyoming. The shape corresponds to the nominate shape with a clear ocher-sand-colored impact on the belly side.
- Tamias amoenus monoensis : in the high altitudes of the central Sierra Nevada in California. The shape is paler and grayer than the nominate shape, the light stripes are very white.
- Tamias amoenus ochraceus : restricted to the Siskiyou Mountains in northern California and southern Oregon. The subspecies is larger than the nominate form, the head and back are clearly ocher colored, the dark stripes are more dark brown.
- Tamias amoenus septentrionalis : north of the Nechako Reservoir in British Columbia. It's a big shape. The inner light stripes are reddish-brown at the head end and become paler towards the rear, the outer pair is white with a reddish wash.
- Tamias amoenus vallicola : in the Bitterroot Valley and neighboring regions in Montana. The shape corresponds to the nominate shape, but is paler overall.
Status, threat and protection
The yellow spruce chipmunk is classified as "least concern" by the International Union for Conservation of Nature and Natural Resources (IUCN). This is justified with the wide spread and regular occurrence; There are no potential risks to the company's existence. The animals are very common locally; in general stand densities of 1.25 individuals per hectare are given.
supporting documents
- ↑ a b c d e f g h i Richard W. Thorington Jr. , John L. Koprowski, Michael A. Steele: Squirrels of the World. Johns Hopkins University Press, Baltimore MD 2012; Pp. 316-318. ISBN 978-1-4214-0469-1
- ↑ a b c d Neotamias amoenus in the IUCN Red List of Threatened Species 2015.3. Posted by: AV Linzey & NatureServe (G. Hammerson), 2008. Retrieved February 13, 2016.
- ↑ a b c Tamias amoenus 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 .
- ^ A b Joel Asaph Allen : A review of some of the North American ground squirrels of the genus Tamias. Bulletin of the American Museum of Natural History 3, 1890; Pp. 45-116. ( Full text , description of the species on pp. 90–92)
- ↑ a b Dallas A. Sutton : Tamias amoenus. Mammalian Species 390, 1992 ( full text ).
literature
- Richard W. Thorington Jr. , John L. Koprowski, Michael A. Steele: Squirrels of the World. Johns Hopkins University Press, Baltimore MD 2012; Pp. 316-318. ISBN 978-1-4214-0469-1
- Dallas A. Sutton : Tamias amoenus. Mammalian Species 390, 1992 ( full text ).
Web links
- Neotamias amoenus inthe IUCN Red List of Threatened Species 2015.3. Posted by: AV Linzey & NatureServe (G. Hammerson), 2008. Retrieved February 13, 2016.