Small pebbles
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Small pebbles ( Spermophilus pygmaeus ), |
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| Scientific name | ||||||||||||
| Spermophilus pygmaeus | ||||||||||||
| ( Pallas , 1778) |
The small pebble ( Spermophilus pygmaeus ) is a type of squirrel from the genus of the ground squirrel ( Spermophilus ). It occurs from eastern Ukraine across parts of Russia (with Dagestan ) to central Kazakhstan .
features
The small pebble reaches a head-trunk length of about 17.5 to 26.0 centimeters and is one of the smaller species of the genus. The tail is about 2.5 to 5.0 centimeters long and, like all ground squirrels, is significantly shorter than the rest of the body. The back color is variable and ranges from a pale gray with a straw yellow wash to a brownish gray. The back has indistinct spots, which, however, are very withdrawn or may be missing. The head is broad, often wider than the body. There is a red spot above the eye. The sides of the body are pale straw yellow with a gray wash. The feet are white to straw yellow. The tail varies greatly in color and can be white, sand-colored, brown or black.
| 1 | · | 0 | · | 2 | · | 3 | = 22 |
| 1 | · | 0 | · | 1 | · | 3 |
The type, like all species of the genus in the upper jaw half per one to a incisor tooth formed incisor (incisor) to which a tooth gap ( diastema follows). This is followed by two premolars and three molars . In contrast, the animals have only one premolar in the lower jaw. In total, the animals have a set of 22 teeth.
distribution
The small pebble occurs in the steppe and semi-desert areas of the Dnepr and the Crimea in Ukraine via the Volga region and the southern Urals of Russia and Dagestan to Central Asia east of the Aral Sea in Kazakhstan . In the course of climate change with an increase in rainfall and humid years in the region, the distribution area has increasingly narrowed in recent years. The species lives in the lowlands at heights of up to 400 or 500 meters.
Way of life
The small pebble is a diurnal ground squirrel. It lives mainly in steppes and semi-desert regions in the lowlands. It feeds mainly on parts of plants, especially leaves, buds and seeds of grasses and herbs and, underground, on roots and tubers. The small pebble also eats crops and grain in agricultural areas. The animals live in colonies in which they defend their territories from neighbors. The males have larger territories that overlap with those of several females, they try to keep other males at a distance and to bind females to themselves. The females also defend their territory from conspecifics. The construction is usually simple with an entrance and one or more nest chambers, it has a length and depth of about one meter. In addition, shallow escape dwellings are being built into which the animals can move in case of danger.
The animals spend the winter, like other ground squirrels, in a long hibernation that begins in August, a little later for young animals and females. It lasts 5 to 8 months, the animals wake up around March to April of the following year. The breeding season begins in spring just after wintering. The six to eight young are born in the underground nest after a gestation period of 25 to 26 days and leave it at the end of spring. Due to the very hot summer, the animals fall into a topor in midsummer and stay in their burrows; this can, with a short interruption, go directly into hibernation, especially with the males.
The main predators of the animals are birds of prey and foxes, to whose presence the animals respond with short, high-pitched alarm calls and escape.
Systematics
The small pebble is classified as an independent species within the genus of the ground squirrel ( Spermophilus ), which currently consists of 15 species following a revision of the genus. The first scientific description comes from the naturalist Peter Simon Pallas from the year 1778. He described the species using individuals from the area of the upper reaches of the Urals in Kazakhstan. Due to the structure of the chromosomes as well as molecular biological and genetic characteristics, it is discussed whether the Caucasus ground squirrel ( Spermophilus musicus ) is con-specific with the small squirrel and should therefore be considered as a subspecies of the same.
Within the species, four subspecies are distinguished together with the nominate form :
- Spermophilus pygmaeus pygmaeus : nominate form; in the Volga region and the southern Urals.
- Spermophilus pygmaeus brauneri : on the Crimean peninsula. The subspecies is paler than the nominate form, the dark tail is reddish in color
- Spermophilus pygmaeus herbicolus : in the central area of the distribution area. The subspecies is often characterized by a rust-red color on the head and tail.
- Spermophilus pygmaeus mugosaricus : in the eastern part of the distribution area, especially in Kazakhstan. The subspecies is paler than the nominate form and has cinnamon or ocher colored spots.
Regionally there can hybridizations with the red-cheeked ground squirrel ( Spermophilus erythrogenys ) and the yellow ground squirrel ( Spermophilus fulvus ,) more often with the russet ground squirrel ( Spermophilus major ) and the spotted suslik ( Spermophilus suslicus come).
Status, threat and protection
The small pebble is classified as Least Concern by the International Union for Conservation of Nature and Natural Resources (IUCN). This is justified with the large population and the large distribution area of the animals. Although there are regional reductions in populations and the disappearance of colonies, the overall population is not endangered. The main reasons for a decline in populations and a reduction in the distribution area, especially in the southern Volga region, are the change in weather and the increase in precipitation in the course of global climate change. Added to this is the threat posed by agriculture with the use of pesticides , irrigation of the fields, overgrazing of pastures and the persecution of ground squirrels as potential grain pests that affect the population numbers.
supporting documents
- ↑ a b c d e f g h Richard W. Thorington Jr., John L. Koprowski, Michael A. Steele: Squirrels of the World. Johns Hopkins University Press, Baltimore MD 2012; Pp. 309-310. ISBN 978-1-4214-0469-1
- ^ Robert S. Hoffmann, Andrew T. Smith: Spermophilus. In: Andrew T. Smith , Yan Xie: A Guide to the Mammals of China. Princeton University Press, Princeton NJ 2008, ISBN 978-0-691-09984-2 , p. 193.
- ↑ a b c d e Spermophilus pygmaeus in the IUCN Red List of Threatened Species 2015.1. Posted by: K. Tsytsulina, I. Zagorodnyuk, N. Formozov, B. Sheftel, 2008. Retrieved July 2, 2015.
- ↑ 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 pygmaeus 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 .
- ^ Richard W. Thorington Jr., John L. Koprowski, Michael A. Steele: Squirrels of the World. Johns Hopkins University Press, Baltimore MD 2012; Pp. 307-308. ISBN 978-1-4214-0469-1
literature
- Richard W. Thorington Jr., John L. Koprowski, Michael A. Steele: Squirrels of the World. Johns Hopkins University Press, Baltimore MD 2012; Pp. 309-310. ISBN 978-1-4214-0469-1
Web links
- Spermophilus pygmaeus inthe IUCN Red List of Threatened Species 2015.1. Posted by: K. Tsytsulina, I. Zagorodnyuk, N. Formozov, B. Sheftel, 2008. Retrieved July 2, 2015.