African ground squirrel
| African ground squirrel | ||||||||||||
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Bristle squirrel ( Xerus sp. ) |
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| Scientific name | ||||||||||||
| Xerus | ||||||||||||
| Hemprich & Ehrenberg , 1833 |
The African bristle squirrels ( Xerus ) are a genus of ground-living ground squirrels that is distributed in Africa with four species.
features
As the name suggests, bristle squirrels have stiff, bristly fur that feels like hedgehog spines when touched. The coat color is yellow-gray to gray-brown, the underside is whitish. Three of the species have a white stripe on each flank, which only the plain-bristle squirrel lacks. The length of the head body is 20 to 45 cm, depending on the species, plus 20 to 25 cm of tail. The weight is between 300 and 900 grams.
| 1 | · | 0 | · | 2 | · | 3 | = 22 |
| 1 | · | 0 | · | 1 | · | 3 |
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 . The teeth in the lower jaw correspond to those in the upper jaw, but only with a premolar. In total, the animals have a set of 22 teeth.
Way of life
African ground squirrels are inhabitants of open habitats , such as savannas, semi-deserts, rocky mountains or scrubland with few trees. Here they live diurnally in self-dug burrows. They form colonies that are likely to resemble those of the prairie dogs , but are nowhere near as well explored. A building that houses a croissant association can have up to a hundred exits and extend over 2000 m². When an enemy approaches and a member of this colony notices them, there are loud warnings, after which all the croissants in their burrow disappear. Birds of prey and mongooses are among the many enemies of the ground squirrel .
The meerkats , which are also potential hunters of the bristle squirrel, sometimes even share burrows with them. They protect the croissants from attackers such as snakes and benefit from the prefabricated housing. Observations have shown that the bristle squirrels are spared by the meerkats in such a community.
In the Cape bristle squirrel, a colony comprises one to four females and numerous young animals. Males always join a colony temporarily and then move on. The defense of the den against conspecifics who do not belong to the association is incumbent on the females. Mating can take place at any time of the year. After a gestation period of 48 days, a female gives birth to one to three young.
Food is all parts of the plant, rarely also insects and bird eggs.
Systematics
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Phylogenetic systematics of the Xerini
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Together with the atlas squirrel ( Atlantoxerus getulus ) and the ground squirrel ( Spermophilopsis leptodactylus ), the African bristle squirrels are assigned to the tribe Xerini . On the basis of features of the lower jaw and molecular biological features of the DNA , a sister group relationship of Atlantoxerus and Xerus is likely. In this case, the ground squirrel, as a sister species of these two genera, would be regarded as a common taxon . The Xerini are also probably the most basic group within the ground squirrels (Xerinae). The distribution of the two genera Atlantoxerus and Xerus , which only occur in Africa today , is traced back to a single settlement by common ancestors of both genera.
The genus contains four species:
- Striped bristle squirrel ( Xerus erythropus ), West and Central Africa
- Cape ground squirrel ( Xerus inauris ), southern Africa
- Kaokoveld bristle squirrel , Damara bristle squirrel ( Xerus princeps ), Angola, Namibia
- Plain bristle squirrel, unstriped bristle squirrel ( Xerus rutilus ), East Africa
The plain bristle squirrel is often assigned to a subgenus Xerus , the striped bristle squirrel Euxerus , and the remaining species are placed in the subgenus Geosciurus . Together with the atlas squirrel ( Atlantoxerus getulus ) and the ground squirrel ( Spermophilopsis leptodactylus ) they form the tribe of bristle squirrels (Xerini).
Humans and bristle squirrels
In South Africa, farmers often mistake ground squirrels for pests, as they also feed on grain and crops. They are also potential carriers of rabies and other infectious diseases. Regionally, they are occasionally kept as pets.
supporting documents
- ↑ Jane M. Waterman: Genus Xerus, Ground Squirrels. In: Jonathan Kingdon, David Happold, Michael Hoffmann, Thomas Butynski, Meredith Happold and Jan Kalina (eds.): Mammals of Africa Volume III. Rodents, Hares and Rabbits. Bloomsbury, London 2013, pp. 93-94; ISBN 978-1-4081-2253-2 .
- ↑ a b c J.M. Mercer, VL Roth VL: The effects of Cenozoic global change on squirrel phylogeny. Science 299 (5622), 2003; Pp. 1568-1572. doi : 10.1126 / science.1079705 , ( full text )
- ↑ a b c Isaac Casanovas-Vilar, Jan van Dam: Conservatism and Adaptability during Squirrel Radiation: What Is Mandible Shape Telling Us? PLOS One, April 4, 2013. doi : 10.1371 / journal.pone.0061298
- ↑ Xerus . 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 .
- ^ Richard W. Thorington Jr. , John L. Koprowski, Michael A. Steele: Squirrels of the World. Johns Hopkins University Press, Baltimore MD 2012; P. 203. ISBN 978-1-4214-0469-1
- ↑ Scott J. Steppan, Brian L. Storz, Robert S. Hoffmann: Nuclear DNA phylogeny of the squirrels (Mammalia: Rodentia) and the evolution of arboreality from c-myc and RAG1. Molecular Phylogenetics and Evolution 30, 2004; Pp. 703-719. ( Full text )
- ↑ MD Herron, JM Waterman, CL Parkinson: Phylogeny and historical biogeography of African ground squirrels: the role of climate change in the evolution of Xerus. Molecular Ecology 14, 2005; Pp. 2773-2788. doi : 10.1111 / j.1365-294X.2005.02630.x
literature
- 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 .
