Ground squirrel
| Ground squirrel | ||||||||||||
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European ground squirrel ( Spermophilus citellus ) |
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Spermophilus | ||||||||||||
| Cuvier , 1825 |
The ground squirrel ( Spermophilus , Syn .: Citellus ) is a genus of ground squirrels that is distributed in 15 species in Eurasia . For a long time the genus included significantly more species that also occur in North America ; However, after a revision on the basis of morphological and molecular biological data, these were divided into a total of eight genera.
In the southern German language area and in some publications , the term Ziesel is interpreted as a neuter ("das Ziesel"), in the Duden and in large parts of Germany as a masculine ("der Ziesel").
features
Most of the ground squirrel are brown or gray on the top and white on the underside. Many species have stripes or spots on them. The tail is relatively short, as are the legs. The head has a typical croissant shape and has stretchable cheek pouches for stowing food. The length of the head body varies between 13 and 40 cm, the length of the tail between 4 and 25 cm, the weight between 85 g and 1 kg, depending on the species.
| 1 | · | 0 | · | 2 | · | 3 | = 22 |
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The species of the genus have a a maxillary per half 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 and habitat
The distribution area of the ground squirrel extends in Eurasia from Eastern Austria through Central Asia and Siberia to Mongolia. The habitat are all types of open habitats, i.e. steppes, semi-deserts, tundras, rocky land and barren mountain ranges. Forest edges and bush land are also accepted, but ground squirrels are absent in dense forests.
There are only two types of ground squirrel in Europe: the European ground squirrel and the pearly squirrel . The former was once widespread in Germany too; a resettlement in the Saxon Eastern Ore Mountains , near the Czech border, took place in 2006 in a covered enclosure. This action was carried out by the BUND -Landesverband Sachsen. Perlziesel are locally present in Eastern European steppe, forest, pasture and fallow landscapes. The perlziesel occupy smaller habitats in Russia, Poland ( Lublin Voivodeship ) and Romania.
Way of life
Ground squirrels live in two types of earthworks: permanent burrows, where they spend the night or their hibernation and give birth and raise their young, and in temporary sheltered structures that serve as short-term refuge. In each building there is a main passage and several side passages as well as nesting and secondary chambers. The earthworks are abandoned during the day to look for food. The ground squirrel feed mainly on seeds , but also on roots , tubers , bulbs and green parts of plants. Also invertebrate animals such as insects are not spurned. In late summer they build up a food supply in their burrows. After the entrance to the building was closed with earth, they hibernate for several months from September to March of the following year, from which they wake up from time to time. According to some researchers, this is how ground squirrels and other rodents repeatedly activate their immune systems . In this way, they are able to keep pathogens such as E. coli bacteria or salmonella in check, which could otherwise multiply in the body of the hibernating animals in an uncontrolled manner and become a life-threatening danger.
Male ground squirrels are territorial and drive their fellows out of the vicinity of their burrows. The females live in the territories of the males and do not defend any territory themselves. In this way the males of some species gather a harem around them; however, there are few social ties, so that one cannot speak of a real colony. The burrows of the females are transferred to their daughters; on the other hand, males are driven away when they reach sexual maturity. If they cannot establish their own territory, they have to survive in the edge zone of other ground squirrel territories, where the conditions are unfavorable and they easily fall prey to predators.
Mating takes place only once a year, between March and May about one to two weeks after leaving the winter quarters. Each female ground squirrel gives birth to 2 to 15 young, with an average litter size of between four and nine depending on the species. Ground squirrels weigh about 10 g at birth. They reach sexual maturity at the age of eleven months. Male ground squirrels reach a lower age at the age of six than females do at eleven, which is due to the expenditure of the territory defense.
Systematics
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Phylogenetic systematics of the Marmotini according to Herron et al. 2004
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The genus spermophilus was 1825 by Frédéric Cuvier in the discussion of the teeth of mammals ( Des dents of mammifères, considérées comme caracteres zoologiques ) introduced , whereby it from Linnaeus 1766 as Mus citellus described and the mice assigned European ground squirrel as type used and first named under the name Spermophilus citellus , which is still valid today . At the same time, the generic name Citellus and the species Citellus citellus , which were coined in 1816 by Lorenz Oken in Oken's textbook on natural history , were also common for a long time . However, all names devised by Oken were invalidated by the International Commission on Zoological Nomenclature (ICZN) in 1956 because they did not follow the Linnean nomenclature . This makes Spermophilus the only valid generic name.
For a long time, almost 40 species were grouped together in the genus, only the antelopesies ( Ammospermophilus ) were listed as a separate genus due to numerous peculiarities. The large number of species has led several authors to attempt to subdivide the genus into sub-genera. After a comprehensive molecular biological investigation, however, the ground squirrel was divided into a total of eight genera, which correspond to the former subgenera, since the original summary of the marmots ( Marmota ), the antelope peas ( Ammospermophilus ) and the prairie dogs ( Cynomys ) is paraphyletic and these groups are therefore not paraphyletic form common taxon .
After the revision, 15 species remain within the genus Spermophilus :
- Alashan ground squirrel ( Spermophilus alashanicus ), Mongolia, Inner Mongolia
- Brandt's ground squirrel ( Spermophilus brevicauda ), in southeastern Kazakhstan and in the far northeast of the People's Republic of China
- European ground squirrel ( Spermophilus citellus ), from Poland and the Czech Republic to the Balkans and western Ukraine
- Daurian ground squirrel ( Spermophilus dauricus ), Mongolia and adjacent parts of Siberia and China
- Red-eared gill ( Spermophilus erythrogenys ), southern Siberia , Mongolia
- Yellow ground squirrel ( Spermophilus fulvus ), Central Asia
- Red and yellow ground squirrel ( Spermophilus major ), Siberia , Mongolia
- Caucasian ground squirrel ( Spermophilus musicus ), Georgia
- Pale ground squirrel ( Spermophilus pallidicauda ), Mongolia and northern People's Republic of China
- Small pebbles ( Spermophilus pygmaeus ), Ukraine, southwest Russia, Kazakhstan
- Tian Shan ground squirrel ( Spermophilus ralli ), eastern Tian Shan in Kyrgyzstan and Kazakhstan and in western Xinjiang in the People's Republic of China
- Relic ground squirrel ( Spermophilus relictus ), Tian Shan in Kyrgyzstan, Kazakhstan and Uzbekistan
- Pearly drizzle ( Spermophilus suslicus ), Poland, Ukraine, Romania , Russia (east to the Volga)
- Taurus ground squirrel ( Spermophilus taurensis ), Turkey
- Asian ground squirrel ( Spermophilus xanthoprymnus ), Caucasus , Anatolia , Syria
The ground squirrel appeared first in the middle Miocene . Ground squirrels first appeared in Europe in the Pleistocene , at that time with a much wider distribution than they are today. Twelve species of ground squirrel are known to be fossilized, but no assignment to the currently valid genera has been made.
People and ground squirrel
Since ground squirrels can be carriers of rabies or tularemia , they are deliberately poisoned in some regions. About the partial recovery of the skins → Zieselfell . However, there are also types of ground squirrel whose population is threatened, including the two European species.
Individual evidence
- ^ 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 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. ( doi : 10.1016 / j.ympev.2003.09.015 , full text , PMID 15120398 )
- ↑ Spermophilus . 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 .
- ↑ Frédéric Cuvier : Des dents des mammifères, considérées comme caracteres zoologiques. 1825 ( digitized ).
- ↑ 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
- ^ Richard W. Thorington Jr., John L. Koprowski, Michael A. Steele: Squirrels of the World. Johns Hopkins University Press, Baltimore MD 2012; Pp. 296-298. ISBN 978-1-4214-0469-1
- ↑ İ. Gündüz, M. Jaarola, C. Tez, C. Yeniyurt, PD Polly & JB Searle: Multigenic and morphometric differentiation of ground squirrels (Spermophilus, Sciuridae, Rodentia) in Turkey, with a description of a new species. Mol. Phylogenet. Evol., 43, pp. 916-935, 2007
literature
- Richard W. Thorington Jr., John L. Koprowski, Michael A. Steele: Squirrels of the World. Johns Hopkins University Press, Baltimore MD 2012; Pp. 300-314. ISBN 978-1-4214-0469-1
- Ronald M. Nowak: Walker's Mammals of the World. 2 volumes. 6th edition. Johns Hopkins University Press, Baltimore MD et al. 1999, ISBN 0-8018-5789-9 .
- 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 .
Web links
- www.wissenschaft.de: The standard language of the ground squirrels - ground squirrels have a sophisticated communication system for warnings
- www.wissenschaft.de: Why ground squirrels don't sleep through the night - rodents wake up from their hibernation time and again to keep infections at bay