Urocyon
Island gray fox ( Urocyon littoralis )
The gray foxes ( Urocyon ) are a genus in the family of dogs ( Canidae ). In English-speaking, they are sometimes also called tree fox ( fox tree ) as they climb, unusual for Canidae, often on trees. Gray fox skins, also called Grisfuchsfell be used commercially.
Features
Gray foxes usually weigh 1.8 to 7 kg. The island gray fox ( Urocyon littoralis ) reaches a head-body length of 48 to 50 cm, gray fox ( Urocyon cinereoargenteus ) from 48 to 68.5 cm. The at least 30% smaller island gray foxes typically have fewer tail vertebrae than the mainland gray foxes ( 15-22 compared to 21-22).
The face, the upper part of the head, back and sides, and the major part of the tail are gray. Throat, the inner sides of the legs and the bottom of the body are white, the sides of the neck, the lower edge and the ventral part of the tail rust colored. The coat is coarse, the hair along the center back and on the tail wearing black lace top and act like a black mane.
Dissemination and development history
The mainland gray fox is distributed from Oregon and southeastern Canada to the west of Venezuela. The smaller island gray foxes, a Inselverzwergung, are endemic to the six major California Channel Islands. It is believed that gray foxes originally 24,000 years ago reached one of the northern islands and during the Pleistocene, about 16,000 years ago who settled three northern islands, when they were joined together. With the rise in sea 9500-11500 years ago, the islands were separated from each other and about 4000 years ago reached the gray foxes, possibly with Native Americans, the southern islands.
Habitat and behavior
Gray foxes inhabit forested areas and bushland, often in mountainous and rugged terrain, the island gray fox is found in all island landforms. The building itself is dug or taken over by other animals, in hollow trees he can to 9 m above the ground. They are crepuscular and nocturnal, the island gray fox also diurnal. Gray foxes feed on small vertebrates, insects and plant food. The herbal diet consists mostly of fruits and cereals and taken from Urocyon frequently than other foxes.
Systematics and evolution
Gray fox ( Urocyon cinereoargenteus )
Island gray fox ( Urocyon littoralis )
Raccoon dog ( Nyctereutes procyonoides )
Bat-eared Fox ( Otocyon megalotis )
South America clade ( Atelocynus, Cerdocyon, Lycalopex, Chrysocyon, Speothos )
Wolf clade (Canis, Cuon, Lycaon )
Gray foxes are mainly regarded as a separate genus, but by Clutton - Brock, Corbet and Hill (1976 ) of the genus Vulpes and Van Gelder (1978 ) of the genus Canis, attributed to the subgenus Vulpes. Urocyon littoralis is often belonging to Urocyon cinereoargenteus as conspecific to the same species, considered a number of recent studies shows that there are different types. In a U. cinereoargenteus attributed population on Isla Tiburón it could possibly be a distinct species.
The genus Urocyon one of two types:
- Gray fox ( Urocyon cinereoargenteus ( Schreber, 1775) ) - Oregon and southeast 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.
On the basis of morphological and molecular data, both types were jointly classified as a sister group of the entire extant dogs while they are allocated in classical systematics usually the genuine foxes ( Vulpini ). This position was confirmed in 2012, a spin-off of the ancestors of the gray foxes from those of all other dogs probably about 16.5 million years ago took place, the separation into the two species known today, however, only about one million years.