Gray foxes
| Gray foxes | ||||||||||||
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Island gray fox ( Urocyon littoralis ) |
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| Scientific name | ||||||||||||
| Urocyon | ||||||||||||
| Baird , 1857 |
The gray foxes ( Urocyon ) are a genus in the family of dogs (Canidae). In the English-speaking world , they are sometimes also called tree fox , as they often climb trees, which is unusual for Canidae. Gray fox skins, also known as gris fox skins , are used commercially.
features
Gray foxes usually weigh 1.8 to 7 kg. The island gray fox ( Urocyon littoralis ) reaches a head-trunk length of 48 to 50 cm, the gray fox ( Urocyon cinereoargenteus ) from 48 to 68.5 cm. The island gray foxes, which are at least 30% smaller, typically have fewer tail vertebrae than the mainland gray foxes (15–22 versus 21–22).
The face, the upper part of the head, the back and the sides, and most of the tail are gray. The throat, the insides of the legs and the underside of the body are white, the sides of the neck, the lower flanks and the ventral part of the tail are rust-colored. The coat is coarse, the hair along the middle of the back and on the top of the tail has black tips and looks like a black mane .
Distribution and history of development
The mainland gray fox is distributed from Oregon and southeastern Canada to western Venezuela . The smaller island gray foxes, an island dwarf , are endemic to the six larger California Channel Islands . It is believed that gray foxes originally reached one of the northern islands 24,000 years ago and colonized the three northern islands during the Pleistocene , about 16,000 years ago, when they were connected. With the rise in sea level 9,500-11,500 years ago, the islands were separated from each other and about 4,000 years ago the gray foxes, possibly with Native Americans , reached the southern islands.
Habitat and way of life
Gray foxes inhabit wooded areas and bushland, often in mountainous and rugged terrain, the island gray fox can be found in all island terrains. The burrow is dug yourself or taken over by other animals, in hollow trees it can be up to 9 m above the ground. They are crepuscular and nocturnal, the island gray fox also active during the day. Gray foxes feed on small vertebrates , insects, and plant foods. The vegetable diet consists mostly of fruits and grains and is consumed by urocyon more often than by other foxes.
Systematics and evolution
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Phylogenetic systematics of dogs
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Gray foxes are predominantly regarded as a separate genus, but are assigned to the genus Vulpes by Clutton-Brock, Corbet and Hills (1976) and to the genus Canis , subgenus Vulpes , by Van Gelder (1978) . Urocyon littoralis is often regarded as conspecific with Urocyon cinereoargenteus , belonging to the same species, but a number of recent studies have shown that they are different species. A U. cinereoargenteus population on Isla Tiburón could possibly be a separate species.
The genus Urocyon includes two species:
- Gray fox ( Urocyon cinereoargenteus ( Schreber , 1775)) - Oregon and southeastern Canada to western Venezuela
- Island gray fox ( Urocyon littoralis Baird 1857) - California Channel Islands San Miguel , Santa Rosa , Santa Cruz , Santa Catalina , San Nicolas and San Clemente , each island population is a separate subspecies.
While the gray foxes are usually assigned to the real foxes (Vulpini) in classical classifications , they are classified in modern classifications on the basis of morphological and molecular biological data as a sister group of all other recent dogs. The splitting off of the ancestors of the gray foxes from those of all other dogs probably took place around 16.5 million years ago, but the separation into the two species known today only took place around a million years ago.
Individual evidence
- ↑ a b c d e f g Ronald M. Nowak: Walker's Carnivores of the World. Johns Hopkins University Press, 2005, ISBN 978-0801880322 , pp. 83-84.
- ^ A b c d David W. Macdonald, Claudio Sillero-Zubiri: The Biology and Conservation of Wild Canids. Oxford University Press, 2004, ISBN 978-0198515562 , p. 28, p. 173.
- ↑ a b Kerstin Lindblad-Toh et al .: Genome sequence, comparative analysis and haplotype structure of the domestic dog. Nature 438, December 2005; Page 803–819. ( Abstract ).
- ↑ Katrin Nyakatura, Olaf RP Bininda-Emonds: Updating the evolutionary history of Carnivora (Mammalia): a new species-level supertree complete with divergence time estimates. BMC Biology 10, 2012. doi : 10.1186 / 1741-7007-10-12
