Townsend ground squirrel
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Townsend ground squirrel ( Urocitellus townsendii ) |
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| Urocitellus townsendii | ||||||||||||
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The Townsend ground squirrel ( Urocitellus townsendii , Syn . : Spermophilus townsendii ) is a species of squirrel from the genus Urocitellus . It is endemic to the south of the American state of Washington .
features
The Townsend ground squirrel reaches a head-trunk length of about 20.0 to 23.2 centimeters, the tail is about 32 to 54 millimeters long and is thus significantly shorter than the rest of the body. The weight is 125 to 175 grams, with the males being slightly heavier than the females. The animals have a single-colored, pale, smoke-gray back coloration with a pink-sand-colored wash. The cheeks and hind legs have a light reddish to rust-red tint, the belly is white to cream-white and also pink-sand-colored. The tail is smoky gray on the top and has a cinnamon brown color on the underside.
distribution
The Townsend ground squirrel is endemic to the south of the American state of Washington, north and west of the Columbia River . The distribution area is limited to the Yakima River Valley west of the Yakima River and the Horse Heaven Hills adjoining it to the south , the total area is less than 7000 km 2
Way of life
The Townsend ground squirrel is diurnal and lives in dry habitats with sparse vegetation and irrigated soils by Sagebrush ( Artemisia tridentata , is marked "sagebrush"). In addition, it occurs in agricultural areas of the distribution area. It is primarily herbivorous and, like other ground squirrels, its diet consists primarily of different parts of the plant such as buds, sprouts and leaves as well as seeds, and insects are occasionally added. The animals live like other ground squirrels on the ground and in underground burrows. The animals hibernate from late May or June to late January or March, with the adult males beginning to hibernate earlier than the females and juveniles.
The mating season begins after the animals wake up in February. The females give birth to a litter of four to 16 pups in March in a nest chamber under construction (the numbers being estimated from embryo counts of captured females). The young animals leave the den after about four weeks in late March to April. The main predators for the Townsend ground squirrel are silver badgers ( Taxidea taxus ) and probably coyotes ( Canis latrans ), birds of prey and the common raven ( Corvus corax ).
Systematics
The Townsend ground squirrel is classified as a separate species within the genus Urocitellus , which consists of twelve species. The species has long been classified as part of the ground squirrel and within the subgenus Spermophilus . After a comprehensive molecular biological investigation, however, the species was assigned to the now independent genus Urocitellus together with several other species . The first scientific description comes from the American zoologist John Bachman from 1839. He described the species as Spermophilus townsendii on the basis of individuals from the area around Wallula on the Walla Walla River near the confluence with the Columbia River in Walla Walla County , Washington. The species was named after the American naturalist John Kirk Townsend (1809-1851), who was best known as a collector and taxidermist and was in close contact with John James Audubon .
Within the species, together with the nominate form, two subspecies are distinguished:
- Urocitellus townsendii townsendii : nominate form; south of the Yakima River and north of the Columbia River, the shape has a chromosome number of 2n = 38.
- Urocitellus townsendii nancyae : north of the Yakima River and west of the Columbia River, the shape has a chromosome number of 2n = 36.
Originally both the Merriam ground squirrel ( Urocitellus canus ) and the Piute ground squirrel ( Urocitellus mollis ) were added to the Townsend ground squirrel, but these are now considered to be separate species.
Status, threat and protection
The Townsend ground squirrel is classified by the International Union for Conservation of Nature and Natural Resources (IUCN) as endangered (vulnerable). This is justified by the very small distribution area of only about 6700 km 2 , the strong decline in usable habitats, which have decreased to about 10% of the original areas, and the strong fragmentation of the populations isolated . Regionally, the species is regarded as a pest and is controlled.
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, ISBN 978-1-4214-0469-1 , pp. 363-364 .
- ↑ a b c d Urocitellus townsendii in the IUCN Red List of Threatened Species 2015.4. Listed by: E. Yensen, NatureServe (G. Hammerson), 2008. Retrieved May 19, 2016.
- ↑ Matthew D. Herron, Todd A. Castoe, Christopher L. Parkinson: Sciurid phylogeny and the paraphyly of holarctic ground squirrels (Spermophilus). Molecular Phylogenetics and Evolution 31, 2004; Pp. 1015-1030. ( Full text , PMID 15120398 )
- ↑ Kristofer M. Helgen, F. Russell Cole, Lauren E. Helgen, Don E. Wilson: Generic Revision in the holarctic ground squirrels genus Spermophilus. Journal of Mammalogy 90 (2), 2009; Pp. 270-305. doi : 10.1644 / 07-MAMM-A-309.1
- ↑ a b c Spermophilus (Spermophilus) townsendii In: Don E. Wilson , DeeAnn M. Reeder (eds.): 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 .
- ↑ Eric A. Rickert: Spermophilus townsendii. Mammalian Species 268, 1987; Pp. 1-6. ( Full text ( Memento of the original from March 15, 2016 in the Internet Archive ) Info: The archive link has been inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this note. )
- ↑ Bo Beolens, Michael Watkins, Michael Grayson: The Eponym Dictionary of Mammals. Johns Hopkins University Press, 2009, ISBN 978-0-8018-9304-9 , p. 416.
literature
- Richard W. Thorington Jr., John L. Koprowski, Michael A. Steele: Squirrels of the World. Johns Hopkins University Press, Baltimore MD 2012; Pp. 363-364. ISBN 978-1-4214-0469-1
- Eric A. Rickert: Spermophilus townsendii. Mammalian Species 268, 1987; Pp. 1-6. ( Full text )
Web links
- Urocitellus townsendii inthe IUCN Red List of Threatened Species 2015.4. Listed by: E. Yensen, NatureServe (G. Hammerson), 2008. Retrieved May 19, 2016.