Merriam Ground Squirrel

Merriam Ground Squirrel
Systematics
Subordination :	Squirrel relatives (Sciuromorpha)
Family :	Squirrel (Sciuridae)
Subfamily :	Ground Squirrel (Xerinae)
Tribe :	Real ground squirrels (Marmotini)
Genre :	Urocitellus
Type :	Merriam Ground Squirrel
Scientific name
	Urocitellus canus
	( Merriam , 1898)

The Merriam ground squirrel ( Urocitellus canus , syn .: Spermophilus canus ) is a species of squirrel from the genus Urocitellus . It is endemic to Oregon in the western United States , as well as in adjacent western Idaho and the far north of California and Nevada .

features

The Merriam-Ground squirrel reaches a head-torso length of about 15.3 to 17.1 centimeters, the tail is about 36 to 40 millimeters long and is thus significantly shorter than the rest of the body. The weight is around 150 grams. The animals are comparatively small with short and narrow tails, they have a uniform gray color on their backs without any noticeable markings or spots. The fur on the back, the cheeks and the hind legs have a pink to sand-colored wash, the belly side is colored white. The tail is gray on top and cinnamon on the underside. The ears are small. Compared to the very similar Piute ground squirrel ( Urocitellus mollis ), the Merriam ground squirrel is smaller with a smaller and wider skull.

distribution

The Merriam ground squirrel is endemic to the western United States in Oregon and in bordering western Idaho to the Snake River and the extreme northwest of California and northeast Nevada .

Way of life

The Merriam ground squirrel is diurnal, with the adult animals being more active at dusk than young animals. It lives mainly in unforested desert and steppe zones of the Chaparral in eastern Oregon as well as in the area of river valleys, open grass areas and pastures up to the Snake River. The desert habitats are very often determined by the sagebrush ( Artemisia tridentata ), the West American juniper ( Juniperus occidentalis ) and Sarcobatus vermiculatus . It often occurs in agricultural fields and irrigation areas, where it can sometimes cause great economic damage. The eastern subspecies Urocitellus canus vigilis in particular is known for its harmful effects on alfalfa plantations.

The Merriam ground squirrel is primarily herbivorous and, like other ground squirrels, its diet consists primarily of various parts of plants such as grass, leaves, fruits and roots, as well as seeds, and occasionally insects. The animals live like other ground squirrels on the ground and in underground burrows. The population densities can be very variable and depend very much on the availability of food, the predator density and the survival rates after winter; they are usually around 20 to 50 animals per hectare. The sexually mature animals begin their hibernation earlier than the young and can retreat to the burrows from mid-July, but usually not until August. You will come out of the burrow again in March.

The mating season begins after you wake up in spring. The young are born in April to early May, and a litter consists of five to ten young. There are no exact data on the length of the gestation period and the lactation period. The most important predators are various birds of prey, predators and snakes. The populations are partly highly fragmented.

Systematics

The Merriam 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 Clinton Hart Merriam from 1898, who described it as Spermophilus mollis canus and thus as a subspecies of the Piute ground squirrel based on individuals from Antelope in Wasco County , Oregon .

Within the species, together with the nominate form, two subspecies are distinguished:

Urocitellus canus canus : nominate form, occurs in most of the distribution area. The nominate form is slightly smaller than Urocitellus canus vigilis , and the skull is also smaller.
Urocitellus canus vigilis : This subspecies colonizes eastern Oregon to the banks of the Snake River in western Idaho. The subspecies is slightly larger than the nominate form and a bit grayer in color.

Status, threat and protection

The Merriam 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, the ability of the species to adapt to changed habitats and the assumed frequent occurrence. Potential hazards arise primarily from the conversion of habitats into agricultural areas. Regionally, the species is viewed and hunted as an agricultural pest, which means that populations are declining.

supporting documents

↑ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j ^k ^l 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. 354-355 .

↑ ^a ^b ^c Urocitellus canus in the IUCN Red List of Threatened Species 2016.1. Listed by: E. Yensen, NatureServe (G. Hammerson), 2008. Retrieved July 13, 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 ( Memento of the original from April 17, 2015 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. , PMID 15120398 ) @1@ 2

↑ 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 Spermophilus (Spermophilus) canus . 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 .

^ F. Russell Cole, Don E. Wilson : Urocitellus canus. Mammalian Species 834, 2009; Pp. 1-8. ( Full text )

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. 354-355 .
F. Russell Cole, Don E. Wilson : Urocitellus canus. Mammalian Species 834, 2009; Pp. 1-8. ( Full text )

Web links

Urocitellus canus inthe IUCN 2016 Red List of Threatened Species . Listed by: E. Yensen, NatureServe (G. Hammerson), 2008. Retrieved July 13, 2016.

[Thorington_et_al._2012-1] ↑ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j ^k ^l 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. 354-355 .