California ground squirrel
| California ground squirrel | ||||||||||||
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California ground squirrel |
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| Scientific name | ||||||||||||
| Otospermophilus beecheyi | ||||||||||||
| ( Richardson , 1829) |
The (or the) Californian ground squirrel ( Otospermophilus beecheyi , Syn . : Spermophilus beecheyi , Citellus beecheyi ) is a rodent of the squirrel family (Sciuridae).
features
The species has a total length of about 30 to 50.8 centimeters. The bushy tail is between 12.7 and 22.9 inches long. The coat is short and smooth. The animals reach a weight of 280 to 738 g. The males are slightly larger than the females. California ground squirrels have brown speckled to blotchy backs. They have light, crescent-shaped markings on the shoulders and neck. The bottom is a slight combination of light brown, gray and white.
distribution
The California ground squirrel occurs in California , western Oregon and Nevada , southwest Washington, and Baja California .
Way of life
The diurnal ground squirrels live mainly in dry habitats that are located at altitudes of up to around 2,200 meters. The species lives as a ground squirrel on the ground. She spends her resting phases in her earthworks. The earthworks are abandoned during the day to look for food. California ground squirrels form colonies, their burrows they build in mostly rocky habitats. In addition, the squirrels are found in agricultural areas and other habitats in the coastal mountain valleys.
food
The ground squirrels spend most of the day gathering food, which they find both on the ground and in the trees. Some of it is consumed right at the place of discovery. They often take it to lookouts and eat it there. In addition, they collect a lot in their cheek pouches and bury it in small holes in the ground. California ground squirrels feed on seeds , fruits , nuts , mushrooms , roots and also on insects and eggs .
Reproduction
California ground squirrels mate in spring. The female is pregnant for about a month. It has between five and eleven young. The boys open their eyes at around 5 weeks and leave the burrow for the first time between the 5th and 8th week.
Systematics
The California ground squirrel is a species of the genus Otospermophilus within the ground squirrel . The first description was in 1829 by John Richardson . First, the species was assigned to the ground squirrel (genus Spermophilus ) together with other taxa that are now considered genera and treated as a subgenus. The generic name Citellus , which was coined in 1816 by Lorenz Oken in "Oken's textbook of natural history", was also used synonymously . The name was already declared invalid in 1956 by the International Commission on Zoological Nomenclature (ICZN) because it did not follow the Linnaean nomenclature .
There are eight subspecies:
- Otospermophilus beecheyi beecheyi (Richardson, 1829)
- Otospermophilus beecheyi douglasii (Richardson, 1829)
- Otospermophilus beecheyi fisheri (Merriam, 1893)
- Otospermophilus beecheyi nesioticus (Elliot, 1904)
- Otospermophilus beecheyi nudipes (Huey, 1931)
- Otospermophilus beecheyi parvulus (AH Howell, 1931)
- Otospermophilus beecheyi rupinarum (Huey, 1931)
- Otospermophilus beecheyi sierrae (AH Howell, 1938)
Hazard and protection
The predators of the California ground squirrel include eagles , badgers , hawks , foxes , rattlesnakes , raccoons and weasels .
California ground squirrels have different strategies for repelling predators. Rattlesnakes can, for example, use their pit organs to identify small temperature differences of 0.2 to 0.4 ° C and thus recognize warm-blooded prey animals well. By waving their tail, California ground squirrels announce their vigilance to attacking rattlesnakes in order to dissuade them from an attack. In doing so, they also raise the body temperature of their tail. The rapid up and down movement of your tail and the subsequent erection of the tail hairs promote blood circulation or increase the amount of heat emitted. Apparently, the visual cue scares the rattlesnake by making the prey appear larger.
Females and young ground squirrels also chew the skinned skin of rattlesnakes to protect themselves from predators in their burrows. Then they smear the skin odor by licking their fur. Some ground squirrels absorb the snake odor from the earth by wallowing in it. Apparently, the assumed snake scent deceives hunting rattlesnakes.
The Californian ground squirrel is classified by the International Union for Conservation of Nature and Natural Resources (IUCN) as “least concern” due to its comparatively large distribution area and stable populations.
literature
- John Richardson, William Swainson, William Kirby: Fauna boreali-americana or the zoology of the northern parts of British America , Spermophilus beecheyi, p. 170 ff., London, J. Murray, 1829–1837, original description of the species (Google- Books)
- BJ Verts, Leslie N. Carraway: Land Mammals of Orego n, pp. 181 ff., University of California Press, 1998, ISBN 978-0520211995
- Eric Yensen, Paul W. Sherman - Ground Squirrels, in George A. Feldhamer, Bruce C. Thompson, Joseph A. Chapman: Wild Mammals of North America: Biology, Management, and Conservation , Second Edition, pp. 211 ff., Johns Hopkins University Press, 2003, ISBN 978-0801874161
Individual evidence
- ^ 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
- ↑ a b c d Animal Diversity Web: Spermophilus beecheyi , accessed May 10, 2015.
- ↑ Itis.gov: IT Report - otospermophilus beecheyi accessed on May 14, 2015
- ↑ Bio.sdsu.edu: Rattlesnake-Squirrel Interactions , accessed May 11, 2015.
- ↑ Spiegel-Online: Behavioral research, stadium wave is used for the vigilance check of January 8, 2014 , accessed on May 11, 2015.
- ↑ Spektrum.de: Californian ground squirrels frighten rattlesnakes with warmth from June 17, 2004 , accessed on May 11, 2015.
- ↑ Peter Kappeler: Behavioral Biology, 3rd edition, p. 109, Springer, 2011, ISBN 978-3-642-20652-8
- ↑ Scinexx.de: Croissants camouflage themselves with snake scent - chewed snake skin as a defense strategy from December 28, 2007 , accessed on May 14, 2015.
- ↑ Iucnredlist.org: Spermophilus beecheyi in the IUCN Red List of Endangered Species 2014.3. Posted by: AV Linzey, R. Timm, ST Álvarez-Castañeda, I. Castro-Arellano, T. Lacher, 2008, accessed on May 10, 2015
