The pika is a close relative of the rabbits and hares, with two upper incisors on each side of the jaw, one behind the other. Being rock-gray in color, pikas are seldom seen until their shrill, metallic call reveals their presence.
With their flattened, oval shaped, long grizzled brownish fur, distinctive white stripe on the forehead (sometimes continuing down the back) and powerful build, badgers are easy to identify.
Beavers, the largest rodents native to North America, measure more than three feet in length, and weigh up to 55 pounds, with a broad, nearly naked, flat tail and webbed feet.
This is a large bat with medium-sized, rounded ears. The wings are long (325-350 mm) and powerful. Color is always some shade of brown, varying from russet to almost black and chocolate.
Long thought to be an accidental wanderer in Colorado, recent data now suggest the presence of breeding colonies has been confirmed in western Colorado.
The bighorn sheep is the mammalian symbol of Colorado Parks and Wildlife and Colorado's official animal.
The largest of our hoofed mammals, bull bison are 10 feet long (not counting the 20 inch tail), and weigh nearly a ton; cows are more than six feet long and weigh up to 1,000 pounds.
Black bears are familiar to everyone, and with the demise of the grizzly bear they are the largest of Colorado's carnivores.
These are large weasels, about the size of a mink, 18 – 22 inches long with a 4- to 6-inch tail.
Black-tailed prairie dogs live on grassy plains or prairies in communities called “towns” which can vary greatly in size.
The bobcat is a familiar animal, but it is secretive and seldom seen. The animals are 32–37 inches long with a tail about 6 inches in length.
The canyon bat is the smallest of Colorado's bats. It is easily recognized by its slow, erratic, butterfly-like flight.
Colorado is home to five species of chipmunks; Colorado chipmunk, Hopi chipmunk, Uinta chipmunk, cliff chipmunk and the least chipmunk.
Colorado is home to three different species of cottontail rabbits; the mountain cotton tail, the desert cottontail, and the eastern cottontail.
The coyote is the size and shape of a small shepherd dog, about four feet in length with a full, black-tipped tail about 14 inches long.
There are two species of deer in Colorado. Mule deer "mulies" have rope-like tails, evenly forked antlers and extravagant ears. White-tails have smaller ears, antlers with a single main beam bearing smaller tines, and, of course, broad white tails.
The wapiti, or elk, is the largest of Colorado's native deer (seven to nine feet long, with a four to six inch tail, and weighing 450 – 900 pounds). Commonly called "elk" in this country, wapiti is a preferred name because elsewhere in the world "elk" refers to the animal we call moose.
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.
The gray wolf ranges across Eurasia and in North America from the Arctic to Mexico and from coast to coast.
The grizzly bear is the largest of North American terrestrial carnivores. Once they occurred throughout Colorado, and they apparently were fairly common in the western three-fifths of the state at least until the turn of the century.
Nearly every part of Colorado is home to at least one species of ground squirrel. All ground squirrels are active in the day; most are common and readily identified and observed.
Jackrabbits are, properly speaking, not rabbits but hares, like the snowshoe hare. Hares have longer feet than rabbits and usually have longer ears.
Two species of harvest mice inhabit Colorado, the western harvest mouse and the plains harvest mouse.
The hoary bat cannot be mistaken for any other species. The tips of the hairs are white or grayish with brown shafts that appear similar to hoar frost, giving the bat its name.
Two species occur in Colorado, the western jumping mouse and the meadow jumping mouse.
The kit fox is a small mammal of the Southwest desert weighing only about three to six pounds, making them about the size of a full-grown jackrabbit, and the smallest fox in North America.
The lynx is a large, bob-tailed cat, three feet long with a black-tipped tail only about one-eighth the total length, and only about half the length of its huge hind foot.
The marten (often called the pine marten or American marten) is a weasel that lives in trees. Males are about two feet long, with an eight inch tail, and they weigh about 1 1/2 pounds.
The mink is a large, brown, semi-aquatic weasel. Males are 20 – 24 inches long, females about one-fifth smaller.
Moose are the largest deer; bulls range to 9 1⁄2 feet long (of which only four inches is tail), six feet tall at the shoulder, with weights to over 1,000 pounds. Antlers are "palmate"— flattened like a hand.
Side-by-side, mountain goats and bighorn sheep look very different, but from a distance a person might mistake a bighorn female for a goat, because bighorn ewes have prominent, gently curved horns.
The mountain lion is called by more names than any other Colorado mammal – cougar, puma, panther, catamount or just plain lion – and all connote respect for a magnificent hunter.
The muskrat is an overgrown, semi-aquatic vole. Muskrats have dense under-fur and a nearly waterproof "overcoat." Their feet are webbed and fringed with stiff hairs.
The armadillo is an unmistakable mammal, with its unique, bony bands of "shell," leathery skin and pig-like snout.
Kangaroo rats are distinctive, up to 11 inches long but weighing only about two and a half ounces. Their elegant tail is longer than their head and body.
The pallid bat is a large, pale, long-eared bat, not easily confused with any other species. Their eyes are large, and their face is covered with wart-like sebaceous glands.
Several kinds of burrowing rodents are sometimes called "gophers," but we should avoid such loose talk and reserve the term for pocket gophers.
Colorado is home to five species of pocket mice; the Great Basin pocket mouse, the hispid pocket mouse, the plains pocket mouse, the silky pocket mouse, and the olive-backed pocket mouse.
he porcupine is familiar to nearly everyone. Second in size only to the beaver among Colorado rodents, porcupines are 27 to 32 inches long (of which ten inches is tail).
Prairie dogs are "barking" squirrels, not dogs, and are among our most "watchable" wildlife.
The pronghorn is a unique North American native. It is a mistake to call them "antelope," as the pronghorn's resemblance to those Old World members of the cow family is rather superficial.
Raccoons need no introduction. With their ringed, bushy tail, yellowish brown fur (with a blackish wash) and black facemask, they are unmistakable. Only their slim, grayish-buff cousin, the ringtail, has similar ringed tail.
As the name indicates, this is a colorful bat, varying from bright reddish to orange. It is a medium-sized bat with long (300 mm) pointed wings and a distinctly long tail and furred uropatagium.
Although sometimes called "ring-tailed cat," this beautiful and seldom-seen mammal actually is a relative of the raccoon, a kinship hinted by the bushy, ringed tail.
The river otter is the longest of our weasels, ranging from 3 to 4 1/2 feet, of which the powerful, cylindrical tail (which thickens toward the base) comprises about one-third.
Nine species of shrews live in Colorado, but most are seldom seen because they live under the vegetation on the forest floor. They are among the least known of our native mammals.
A medium-sized bat with black hair tipped in silver or yellow; the silver-haired bat is one of Colorado's most distinctive and attractive mammals. Wingspan ranges from 270 to 310 mm.
Four species of skunks are known in Colorado: striped, eastern and western spotted, and white-backed hog-nosed.
Colorado's rarest bat is perhaps its most striking. The spotted bat has enormous pink ears and three large white spots on the black dorsal surface.
Colorado is home to three kinds of tree squirrels: The rusty red fox squirrel; Abert's squirrel, which has a striking black or salt-and-pepper gray coat and magnificent ear-tufts; and the smaller but noisier pine squirrel, or chickaree.
Most of the eight species of voles that make Colorado home are brownish in color, but the sagebrush vole is gray and the southern red-backed vole has a brick-red patch on its back.
Of the eight members of the weasel family known in Colorado, only two actually are called weasels: the long-tailed weasel and the ermine, or short-tailed weasel.
A small bat with a very small (8 mm) foot and dull to burnished brown pelage. The ears are dark, nearly black, and a distinct facial mask is frequent.
Colorado is home to six species of white-footed mice – the deer mouse, brush mouse, pinyon mouse, canyon mouse, rock mouse and just plain white-footed mouse.
Wolverine have a reputation larger than life, but they are impressive weasels by any standard. Wolverine are three feet long, with a rather short tail, just one-quarter the total length.
Woodrats – familiarly known as "pack rats" – are beautiful and interesting animals that hardly deserve the negative stereotype most people have of "rats."
The marmot is the largest of our ground squirrels, a close relative of the woodchuck of the East and Midwest.