Scientific Name: Genus Vulpes
Four species of foxes make Colorado home. Red and gray foxes are three feet long and weigh nine to 11 pounds. Red foxes are reddish orange above, white below, and have a white-tipped tail and black ears, legs, and feet. Gray foxes have black fur running down the top side and tip of the tail, reddish ears and feet and a mane of stiff black hairs on their grayish brown back. Swift and kit foxes are only 27 to 36 inches long; their tails are as long as their bodies and black only at the tips. They weigh just four to seven pounds.
The red fox lives in riparian woodland and wetlands on the plains and in forest-edge communities in the mountains. The gray fox is found mostly in brushy areas in canyons and along the foothills. The tiny swift fox is a species of the eastern plains and its near relative, the kit fox, lives in desert shrub-lands in the western valleys.
Foxes mostly eat rodents, rabbits and birds. The smaller fox species eat large quantities of insects. The gray fox is distinctive in that it sometimes forages in trees for fruit and nestling birds. Red and gray foxes are most active at dawn and dusk; the smaller, arid-land foxes are more nocturnal.
Coloradan foxes all produce a single litter of young per year. Gestation periods range from seven to eight weeks, and litter sizes probably average around four. Gray and kit foxes are not particularly common in most of their range in Colorado. Red foxes have increased greatly with the growth of irrigated agriculture throughout the state. Swift foxes were nearly driven to extinction as an unintended side effect of programs to eradicated wolves and coyotes, but now are recovering.
By David M. Armstrong Department of Ecology & Evolutionary Biology Environmental Studies Program, University Museum of Natural History University of Colorado-Boulder