GRAY F O X

The gray fox (Urocyon cinereoargenteus), or grey fox, is a carnivorous mammal of the family Canidae, widespread throughout northern and central America. This species and its only congener, the diminutive Channel Island fox (Urocyon littoralis), are the only living members of the genus Urocyon, which is considered to be the most basal of the living canids. Though it was once the most common fox in the eastern United States, and still is found there, human advancement and deforestation allowed the red fox to become more dominant. The Pacific States still have the gray fox as a dominant. It is the only American canid that can climb trees.

Description
The gray fox is mainly distinguished from most other canids by its grizzled upper parts, black-tipped tail and strong neck, while the skull can be easily distinguished from all other North American canids by its widely separated temporal ridges that form a U-shape. There is little sexual dimorphism, save for the females being slightly smaller than males. The gray fox ranges from 76 to 112.5 cm (29.9 to 44.3 in) in total length. The tail measures 27.5 to 44.3 cm (10.8 to 17.4 in) of that length and its hind feet measure 100 to 150 mm (3.9 to 5.9 in). The gray fox typically weighs 3.6 to 7 kg (7.9 to 15.4 lb), though exceptionally can weigh as much as 9 kg (20 lb). It is readily differentiated from the red fox by the lack of "black stockings" that stand out on the latter and the stripe of black hair that runs along the middle of the tail as well as individual guard hairs being banded with white, gray, and black.[5] The gray fox displays white on the ears, throat, chest, belly and hind legs. In contrast to all Vulpes and related (Arctic and fennec) foxes, the gray fox has oval (instead of slit-like) pupils.

Scientific classification

Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Carnivora
Family: Canidae
Genus: Urocyon

Species: U. cinereoargenteus

Origin and genetics


The gray fox appeared in North America during the mid-Pliocene (Hemphillian land animal age) epoch 3.6 million years ago (AEO) with the first fossil evidence found at the lower 111 Ranch site, Graham County, Arizona with contemporary mammals like the giant sloth, the elephant-like Cuvieronius, the large-headed llama, and the early small horses of Nannippus and Equus. Genetic analyses of the fox-like canids confirmed that the gray fox is a distinct genus from the red foxes (Vulpes spp.). Genetically, the gray fox often clusters with two other ancient lineages, the east Asian raccoon dog (Nyctereutes procyonoides) and the African bat-eared fox (Otocyon megalotis). The chromosome number is 66 (diploid) with a fundamental number of 70. The autosomes include 31 pairs of sub-graded subacrocentrics, but one only pair of metacentrics. Faunal remains at two northern California cave sites confirm the presence of the gray fox during the late Pleistocene. Genetic analysis has shown that the gray fox migrated into the northeastern United States post-Pleistocene in association with the Medieval Climate Anomaly warming trend. Recent mitochondrial genetic studies suggests divergence of North American eastern and western gray foxes in the Irvingtonian mid-Pleistocene into separate sister taxa.


The gray fox's dwarf relative, the Channel Island fox, is likely descended from mainland gray foxes. These foxes apparently were transported by humans to the islands and from island to island, and are descended from a minimum of 3–4 matrilineal founders. The genus Urocyon is considered to be the most basal of the living canids.

Life Cycle

Mating season is between January and April. About 53 days after mating, the female gives birth to one to seven pups. The male helps feed the pups. They are weaned when they are about three months old and are able to hunt on their own when they are four months old. The pups leave their mother in the autumn. The same males and females usually mate together every year.

Range

The gray fox can be found from southern Canada to northern Columbia and Venezuela. It is not found in some mountainous parts of the Northwest United States and in the Great Plains. 


sources:
http://www.nhptv.org/wild/images/grayfoxmap.jpg
https://www.google.co.id/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&cad=rja&uact=8&ved=0ahUKEwjSipPvg9fYAhUFjJQKHTaiA6QQFgg0MAE&url=https%3A%2F%2Fen.wikipedia.org%2Fwiki%2FGray_fox&usg=AOvVaw2qnSrhXh1oe98CJOBDEDV8