Pocket rats
| Pocket rats | ||||||||||||
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A pocket rat |
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| Geomyidae | ||||||||||||
| Bonaparte , 1845 |
The pocket rats (Geomyidae) are a family of North and Central American burrowing rodents with about 40 species in six genera.
features
Pocket rats have very small eyes and ears. Her body is plump, her legs short. The bare tail is relatively short, but has a very sensitive sense of touch . As an adaptation to the burrowing way of life, the tear glands constantly secrete a thick substance to protect the eyes from the ingress of dirt; the teeth are located outside the lips, which can be closed without gaps behind them. This allows the animals to use their teeth to dig without sand getting into their mouths. There are five strong digging claws on each forefeet. The body size varies between 9 and 30 cm (head body length), plus 4 to 14 cm tail.
Pocket rats are named after the large fur pockets that are used to stow food. These are located on the outside of the cheek and can be turned outward for cleaning purposes.
distribution
The distribution ranges from southern Canada through the USA and Mexico to Panama . By far the largest number of species live in Mexico. Pocket rats of the species Thomomys talpoides were one of the few animal species that survived the 1980 eruption of Mount St. Helens in relatively large numbers.
Way of life
Pocket rats spend almost their entire lives underground. Only in exceptional cases does the search for food lead them to the surface. They dig two different types of tunnels: the foraging tunnels run close to the surface and are very narrow; the dwellings with nest, sleeping and storage chambers are deeper and reach considerable dimensions. Pocket rats do not hibernate . Especially in the northern regions of their distribution area, however, they stop digging in the cold season.
Pocket rats eat the underground parts of plants, i.e. roots and tubers. They stow the food in their cheek pouches and bring them to the lower-lying pantries. The enemies are mainly burrowing predators such as skunks and silver badgers . Some snakes of the genus Pituophis follow the pocket rats in their passages and are known as "gopher snakes" because of this specialization in their homeland.
Pocket rats are strictly solitary animals who only come together briefly to reproduce. Otherwise, if two old animals meet, there will be fierce fighting. A female gives birth to two to ten young per litter.
Systematics
While McKenna and Bell unite the pocket rats as a subfamily with the pocket mice in a common family, the Geomyidae are an independent family in the majority of sources. A close relationship with pocket mice is undisputed. Pocket rats have been known to be fossilized since the Oligocene .
Within the pocket rats, the following genera with a total of around 40 species are distinguished:
- Cratogeomys Merriam , 1895, with seven species in Mexico and the southern United States, was originally a subgenus of Pappogeomys viewed
- Flatland pocket rats ( Geomys Rafinesque , 1817) with nine species from southern Canada to central Mexico
- Taltuzas or giant pocket rats ( Orthogeomys Merriam , 1895) with eleven species from southern Mexico to Panama
- Pappogeomys Merriam, 1895, with two species in Mexico
- Mountain pocket rats ( Thomomys Wied-Neuwied, 1839) with nine species from southern Canada to northern Mexico
- Tuzas ( Zygogeomys Merriam, 1895) with a species in Mexico
Trivia
Mima Mounds is a hilly landscape that may have been created through centuries of bioturbation by pocket rats. The pocket rat is the mascot of the Go programming language .
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 .
- Malcolm C. McKenna, Susan K. Bell: Classification of Mammals. Revised Edition. Above the species level. Columbia University Press, New York NY 2000, ISBN 0-231-11013-8 .
Individual evidence
- ^ Douglas C. Andersen, James A. Macmahon: Plant Succession Following the Mount St. Helens Volcanic Eruption: Facilitation by a Burrowing Rodent, Thomomys talpoides. In: American Midland Naturalist. Vol. 114, No. 1, July 1985, ISSN 0003-0031 , pp. 62-69.
- ↑ Geomyidae. 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 . Retrieved March 14, 2010
- ^ Mark S. Hafner, Theresa A. Spradling, Jessica E. Light, David J. Hafner, and John R. Demboski: Systematic revision of pocket gophers of the Cratogeomys gymnurus species group. Journal of Mammalogy 85, 2004, pp. 1170-1183
- ↑ Mark S. Hafner, Jessica E. Light, David J. Hafner, Sara V. Brant, Theresa A. Spradling and James W. Demastes: Cryptic species in the Mexican pocket gopher Cratogeomys merriami. Journal of Mammalogy 86 (6), 2005, pp. 1095-1108
- ↑ Cratogeomys. 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 . Retrieved March 14, 2010
