Silver-gray earth auger
| Silver-gray earth auger | ||||||||||||
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Adult silver-gray earth auger |
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| Systematics | ||||||||||||
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| Scientific name of the genus | ||||||||||||
| Heliophobius | ||||||||||||
| Peters , 1846 | ||||||||||||
| Scientific name of the species | ||||||||||||
| Heliophobius argenteocinereus | ||||||||||||
| Peters, 1846 |
The Silbergraue auger ( Heliophobius argenteocinereus ) or Silbermull , is the only kind of the rodent - genus auger ( Heliophobius ) within the family of blesmol (Bathyergidae). These are rodents that are mainly adapted to the underground and burrowing way of life.
features
The auger, like its close relatives, the gray mole rat and the naked mole rat , is adapted to a burrowing way of life. Accordingly, it has a very short, silver-gray fur and its ears and tail are very much receded. The eyes are also very small. The large incisor teeth that are used as digging tools are striking .
This rodent reaches a head-torso length of 10 to 20 cm and a weight of about 160 grams. The 1.5 to 4 cm long tail is covered by stiff fringes of hair.
distribution and habitat
The silver-gray earth auger lives in the steppe and forest regions in East Africa. The distribution area ranges from Kenya to Tanzania and Malawi to the Zambezi in Mozambique . In the west, the species reaches the southeastern Democratic Republic of the Congo and central Zambia . It prefers dry and sandy soils.
Way of life
In contrast to the naked mole rat and gray mole rat that live in colonies, the auger is a loner who digs its tunnel system into dry and soft ground. The animals orientate themselves within the corridors obviously with the help of the earth's magnetic field , the structure of the caves changes seasonally. The building consists of a main tunnel about 47 meters long, a living chamber and many branches. The chamber has a diameter of 8 to 10 cm and lies about 30 cm below the surface of the earth. There are separate places in the tunnel system for food supplies and faeces. Augers feed on tubers that they find and use when digging.
On the Nyika plateau, the animals live sympathetically with the Malawi gray mulls ( Fukomys whytei ) living in colonies , with the auger in the softer soils of the higher-lying afromontane grass areas and the gray mole in the harder soils of the lower-lying tree savannas of the Miombo type . As a solitary species, the silver-gray earth auger is probably not able to colonize the harder and less nourishing soils of the forests, in which the colonies of the gray mull offer advantages through the division of labor. On the other hand, it is more competitive in the softer and colder soils of the high altitudes, in which the gray mole is probably unable to prevail, mainly due to its less effective thermoregulation and other factors.
Outside the mating season, the animals are very aggressive towards conspecifics. The reproductive behavior is still quite insufficiently researched. In the few females observed, gestation lasted about 87 days. 2 to 3 blind and naked young animals (in exceptional cases 1 or 4) with a weight of about 7 grams were born per litter. One specimen lived under human supervision for two years and then in the wild for another year.
status
The silver-gray earth auger is fought locally as an agricultural pest. It is also caught and eaten by humans in its homeland. Since this has no obvious impact on the population, the IUCN lists it as not at risk ( least concern ).
literature
- CG Faulkes, E. Verheyen, W. Verheyen, JUM Jarvis, NC Bennett: Phylogeographical patterns of genetic divergence and speciation in African mole-rats (Family: Bathyergidae). In: Molecular Ecology. Vol. 13, No. 3, 2004, ISSN 0962-1083 , pp. 613-629, doi : 10.1046 / j.1365-294X.2004.02099.x .
- Tali Kimchi, Ariane S. Etienne, Joseph Terkel: A subterranean mammal uses the magnetic compass for path integration. In: Proceedings of the National Academy of Science. Vol. 101, No. 4, 2004, ISSN 0027-8424 , pp. 1105-1109, doi : 10.1073 / pnas.0307560100 .
- 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 .
- Andreas Scharff, M. Macholan, J. Zima, Hynek Burda: A new karyotype of Heliophobius argenteocinereus (Bathyergidae, Rodentia) from Zambia with field notes on the species. In: Mammalian Biology . Vol. 66, No. 6, 2001, pp. 376-378.
- Radim Sumbera, Hynek Burda, Wilbert N. Chitaukali: Reproductive biology of a solitary subterranean Bathyergid rodent, the silvery mole-rat (Heliophobius argenteocinereus). In: Journal of Mammalogy . Vol. 84, No. 1, 2003, pp. 278-287.
- Radim Sumbera, Hynek Burda, Wilbert N. Chitaukali, Jana Kubova: Silvery mole-rats (Heliophobius argenteocinereus, Bathyergidae) change their burrow architecture seasonally. In: Natural Sciences. Vol. 90, No. 8, 2003, ISSN 0028-1042 , pp. 370-373, doi : 10.1007 / s00114-003-0439-y .
Individual evidence
- ↑ a b c d Nowak: Walker's Mammals of the World. Volume 2. 1999, pp. 1639-1940.
- ↑ a b Heliophobius argenteocinereus in the endangered Red List species the IUCN 2011. Posted by: Maree, S. & Faulkes, C., 2008. Accessed September 12, 2012 found.
- ↑ Bruce G. Marcot (2004), short portrait with pictures ( Memento of the original from December 27, 2012 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. (English)
- ↑ M. Lövy, J. Šklíba, H. Burda , WN Chitaukali & R. Šumbera: Ecological characteristics in habitats of two African mole-rat species with different social systems in an area of sympatry: implications for the mole-rat social evolution. Journal of Zoology 286, Feb. 26, 2012; Pp. 145-153. doi : 10.1111 / j.1469-7998.2011.00860.x , ( full text ).
Web links
- Bruce G. Marcot (2004), short portrait with pictures (English)