Kaokoveld bristle squirrel
| Kaokoveld bristle squirrel | ||||||||||||
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Kaokoveld ground squirrel ( Xerus princeps ) in Etosha National Park |
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| Xerus princeps | ||||||||||||
| ( Thomas , 1929) |
The Kaokoveld or Damara bristle squirrel ( Xerus princeps ) is a type of squirrel from the genus of the African bristle squirrel ( Xerus ). It occurs in a narrow area in the Namib and adjacent regions from southwestern Angola to southwestern Namibia .
features
The Kaokoveld bristle squirrel reaches an average head-trunk length of 23.0 to 29.0 centimeters, the tail is 20.5 to 28.2 centimeters long. The weight is about 570 to 720 grams. The rear foot length is 65 to 75 millimeters, the ear length 12.5 to 15 millimeters. It is a large ground squirrel with a rough, short back fur that is cinnamon-brown with white spots. It consists of sandy yellow to dark brown hair with a white tip. The skin is black. On the sides of the body there is a noticeable white stripe that extends from the shoulders to the hips. The peritoneum is white. The eyes are large and have a matt white eye stripe above and below that extends to the nostrils. The ears are small. The length of the tail corresponds approximately to the length of the head and trunk. It is flattened dorso-ventrally and covered with hair about 70 millimeters long, each white with three black bands and a white tip, giving the tail an indistinct banding. The tip of the tail is white. The females have two paired teats (0 + 0 + 1 + 1 = 4). The genome consists of a diploid chromosome set of 2n = 38 chromosomes.
| 1 | · | 0 | · | 2 | · | 3 | = 22 |
| 1 | · | 0 | · | 1 | · | 3 |
The skull has a total length of 54.6 to 61.4 millimeters and a width of about 33.4 to 37.1 millimeters. Like all species of the genus has the type 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 . 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. The front teeth of the incisor teeth are colored white or pale orange. The bony palate ends well before the front edge of the last molars.
The appearance of the Kaokoveld bristle squirrel corresponds primarily to the Cape bristle squirrel ( Xerus inauris ), which occurs in southern Africa from Namibia to South Africa. It is somewhat smaller, has white incisor teeth and is less grayish in body color, the tail hair has only two black bands and the tail is shorter in comparison.
distribution
The Kaokoveld bristle squirrel occurs in the Namib and neighboring regions from southwestern Angola to southwestern Namibia .
Way of life
The Kaokoveld bristle squirrel lives in the regions of the Succulent Karoo and Nama Karoo in arid areas with an annual rainfall of about 125 to 250 millimeters. The habitats are characterized by stony scree areas or open basin landscapes with individual trees or a few bushes. The animals are diurnal and live terrestrially on the ground, when it is very hot or raining they retreat into their burrows. The animals leave the den in the early morning and then heat up briefly. They feed primarily herbivorous of roots and grass stems. In mopane populations ( Colophospermum mopane ) the animals also climb into the bushes and eat mopane leaves and the aphids living there, Copaifera mopane .
Kaokoveld bristle squirrels usually occur as solitary animals or in small family groups of two to four individuals, which consist of a mother and up to three young. Adult males can be easily associated with families, but are usually solitary and visit females in the area only to mate. There are no sightings of common comfort behavior and games. The burrows of the animals are simple and have a single nesting chamber about 70 centimeters deep, their two to five entrances are usually under piles of stones or in rubble. Normally the animals avoid sandy soils for their burrows, but rarely do they build simple burrows here too, which can then be recognized by piles of sand at the entrance. There is a distance of about 80 meters between the individual burrows, and the distance between neighboring burrows of the sympathetic Cape bristle squirrel is at least 200 meters. The temperature in the building is a maximum of 32 ° C during the day with outside temperatures around 38 ° C and at night around 25 ° C with outside temperatures of around 10 ° C. When the sun is strong, the animals shade their bodies with their tails and seek shelter in the shade of stones or vegetation. They are adapted to temperatures of 32 to 35 ° C, hyperthermia begins at 35 ° C and increased salivation was registered at temperatures above 38 ° C. The heat given off to the environment is high and the water balance is very efficient, so that the faeces, with an average water content of 14.2%, are significantly drier than that of the related Cape bristle squirrel.
There is limited information on mating and reproduction of the species. The young are likely only born in winter. The gestation period is about six to seven weeks and the litter of a female consists of one to three young. The young animals open their eyes after about 21 days. No information is available about potential predators, only the flea Ctnochephalides connatus has been documented as an ectoparasite .
Systematics
The Kaokoveld bristle squirrel is classified as an independent species within the genus of the African bristle squirrel ( Xerus ), which consists of four species. The first scientific description comes from the British zoologist Oldfield Thomas from 1929, who described the animals as Geosciurus princeps using individuals from Otjitundua in the central Kaokoveld .
Apart from the nominate form, no subspecies are distinguished within the species .
Status, threat and protection
The Kaokoveld bristle squirrel is listed as “least concern” by the International Union for Conservation of Nature and Natural Resources (IUCN). This is justified by the comparatively large distribution area and the assumed large populations of animals in their habitat, which also includes several protected areas. There are no known threats to the species' existence.
supporting documents
- ↑ a b c d e f g h i j k l m n o Jane M. Waterman: Xerus princeps, Damara Ground Squirrel. 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. 99-100; ISBN 978-1-4081-2253-2 .
- ↑ a b c d e f g h i j Richard W. Thorington Jr. , John L. Koprowski, Michael A. Steele: Squirrels of the World. Johns Hopkins University Press, Baltimore MD 2012; Pp. 207-208. ISBN 978-1-4214-0469-1
- ↑ 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 Xerus princeps in the IUCN 2016-2 Red List of Threatened Species . Posted by: M. Griffin, N. Coetzee, 2008. Retrieved September 19, 2016.
- ↑ Xerus princeps . 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; Pp. 207-208. ISBN 978-1-4214-0469-1
- Jane M. Waterman: Xerus princeps, Damara Ground Squirrel. 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. 99-100; ISBN 978-1-4081-2253-2 .
Web links
- Xerus princeps inthe IUCN 2016-2 Red List of Threatened Species . Posted by: M. Griffin, N. Coetzee, 2008. Retrieved September 19, 2016.