Piute ground squirrel
| Piute ground squirrel | ||||||||||||
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| Urocitellus mollis | ||||||||||||
| ( Kennicott , 1863) |
The Piute ground squirrel ( Urocitellus mollis , syn .: Spermophilus mollis ) is a species of squirrel from the genus Urocitellus . It occurs in the western United States from southeastern Oregon and southern Idaho through Nevada to the extreme north of California and western Utah .
features
The Piute ground squirrel reaches a head-trunk length of about 20.1 to 23.3 centimeters, the tail is about 44 to 61 millimeters long and is thus significantly shorter than the rest of the body. The weight is around 80 to 200 grams. The animals have a uniform smoky gray back coloration with sand-colored or pink-colored washings without any noticeable markings or spots. The cheeks and the hind legs have a reddish to rust-red wash, the belly is white to cream-colored. The tail is smoky gray on the top and cinnamon-colored on the underside. Compared to the very similar Merriam Ground Squirrel ( Urocitellus canus ), the Piute Ground Squirrel is larger with a larger and narrower skull.
The genome consists of 2n = 36 chromosomes .
distribution
The Piute ground squirrel occurs in the western United States from southeastern Oregon and southern Idaho through Nevada to the extreme north of California and western Utah .
Way of life
The Piute ground squirrel is diurnal, with the adult animals being more active at dusk than young animals. He lives mainly in desert habitats, which are determined by the sagebrush ( Artemisia tridentata ) and other typical plants. It often lives near springs or irrigated fields.
The Piute ground squirrel is primarily herbivorous and, like other ground squirrels, its diet consists primarily of different parts of plants such as grass, leaves, sprouts, fruits and roots as well as the seeds of the plants that occur, as well as occasional insects and other animal foods. They also often eat grain and other crops grown in agricultural land. They find their food on the ground, but they can also climb into the bushes. The animals live like other ground squirrels on the ground and in complex underground burrows. The burrows that are used for rearing young and for hibernation usually have several chambers and entrances and penetrate the ground to a depth of about one meter. The animals also dig short and shallow escape burrows. The Piute ground squirrel can live in colonies, although the individual individuals with the exception of the dams with their young are not very social and live as solitary animals. The animals' activity space is around 0.14 hectares. The sexually mature males begin their hibernation in May, while the females and the young do not retreat into the burrows until July. They come out of their burrows from January to March, with the males leaving them about three weeks before the females.
The mating season begins after waking up in January to March, but can be delayed in dry seasons. There is only one litter per year. The young are born in the underground nest after a gestation period of 24 days, and a litter consists of five to ten young. The males usually reach sexual maturity after one to two years, females have their own young after one year. The reproduction rate is very high, but the mortality of the animals is also around 70 percent. Accordingly, only about 30 percent of the ground squirrel survive each year. The most important predators are various predators such as the silver badger ( Taxidea taxus ), the coyote ( Canius latrans ) and weasels ( Mustela genus ), as well as birds of prey and common ravens ( Corvus corax ).
Systematics
The Piute ground squirrel is classified as an independent 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 Robert Kennicott from 1863, who described it as Spermophilus mollis on the basis of individuals from Camp Floyd near Fairfield in Utah County , Utah . The species was partially regarded as a subspecies of the Townsend ground squirrel ( Urocitellus townsendii ) together with the Merriam ground squirrel , but recognized as a separate species due to the different number of chromosomes .
Within the species, together with the nominate form, three subspecies are distinguished:
- Urocitellus mollis mollis : nominate form, occurs in most of the distribution area. The nominate form is medium-sized compared to the other subspecies.
- Urocitellus mollis artemisiae : This subspecies colonizes the Snake River Plain in central Idaho. It's the smallest form.
- Urocitellus mollis idahoensis : This subspecies lives in west-central Idaho, northeast of the Snake River . The subspecies is slightly larger than the nominate form and the back fur is slightly speckled. The tail is also a little longer, wider and darker.
Status, threat and protection
The Piute ground squirrel is classified as Least Concern (LC) by the International Union for Conservation of Nature and Natural Resources (IUCN). This is justified by the comparatively large distribution area and the assumed frequent occurrence. Potential hazards arise primarily from the conversion of habitats into agricultural areas and the deterioration of habitats. A decline in southwest Idaho in the late 1980s was due to landscape fires transforming the bush steppes into a landscape dominated by annuals. Regionally, the animals are fought as pests with poison and by shooting. In addition, they belong to the traditional prey of some Indians , although this hunt has little impact on the population.
supporting documents
- ↑ a b c d e f g h i j k l m 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. 359-360 .
- ↑ a b c d Urocitellus mollis in the IUCN Red List of Threatened Species 2016.1. Posted by: G. Hammerson, 2008. Retrieved August 20, 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
- ^ Robert Kennicott: Descriptions of four new species of Spermophilus, in the collections of the Smithsonian Institution. Academy of Natural Sciences of Philadelphia Proceedings, 1863; Pp. 157-158. ( Digitized version )
- ↑ a b 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. )
- ↑ a b Spermophilus (Spermophilus) mollis . 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 .
literature
- 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. 359-360 .
Web links
- Urocitellus mollis inthe IUCN Red List of Threatened Species 2016.1. Posted by: G. Hammerson, 2008. Retrieved August 20, 2016.