Pronghorn are a uniquely North American animal that is a common sight in the Colorado prairies. Prong-horns are recognizable for their reddish-tan coloring and their white rear-ends. They are Colorado’s smallest hoofed mammals, weighing in between 85 and 100 pounds. A pronghorn can run up to 60 miles an hour, making it the fastest animal in North America. Their name comes form their oddly shaped horns which have forward facing prongs. Both males and females have horns, though the males are larger than the females. In the late fall, the horns brake off and are replaced by a new set. They live in small groups during the summer and form large herds during the winter.
Coyotes are a common animal across Colorado. They range all over the state, from rural areas to big cities. Coyotes are the size and shape of a medium sized dog, weighing between 30 to 40 pounds. Coyotes are omnivores, which means they eat both plants and animals. They are both scavengers and hunters. They hunt small mammals like rabbits and mice. They are equally happy to eat household pets or human trash. They tend to be the most active in the early morning or the late evening, but unlike other animals, they can also bee seen during the day and night.
Prairie dogs make their homes in the grasslands of Colorado. There are three species of these rodents living in Colorado; the black-tailed prairie dog, the white-tailed prairie dog and the Gunnison’s prairie dog. They live in family groups that contain up to 26 animals. They build colonies with other families in net-works of tunnels called Dog Towns. These colonies can be made up of hundreds of family groups! Prairie dogs eat grasses and other plant matter. They hibernate in the winter, fattening themselves up in the fall to survive buried deep in their holes through the coldest months. Prairie dogs get their name form the sharp “barking” noise they make when warning each other when they sense danger.
Barred Tiger Salamanders are common in Colorado, making their homes near lakes, ponds, reservoirs and pools across the state. They are the most active at night during damp weather. These salamanders are known as “mole salamanders’ because the spend most of their lives underground. They are known to use hole left by other animals and can also be found under rocks, stumps and in man made holes such as irrigation control boxes. Salamanders reproduce using a process called metamorphosis. Females lay fertilized eggs in calm water, attaching them to twigs, grass stems and leaves. The eggs hatch into a larvae which continues to develop over the next 2 to 5 months.
Great plains ratsnake can be found in west-central Colorado around the Grand Valley and the Colorado National Monument area. The ratsnake’s upper side is gray with a pattern of dark-edged blotches running down its length. The western Colorado ratsnake is smaller than its eastern cousin, growing between 30 to 47 inches in length. They can be found in river valleys and canyon bottoms along with grasslands and conifer woodlands. They can climb, making their way into trees and shrubs and even rocky ledges and buildings. The ratsnake is a constrictor. It uses its body to squeeze the life from its prey, taking away the ability to breath and suffocating the animal. They feed mainly on rodents.
The black bear is the most common bear in North America and calls most of Colorado home. The name “Black Bear” can be deceiving because their shaggy hair can be black, dark brown, cinnamon or yellowy-brown. They grow between 4 to 7 feet long from nose to tail but can stand up to 8 feet tall. They are omnivores, though much of their diet is plant based. They hibernate during the winter months, packing on weight in the late fall to prepare. They sleep for months without eating, drinking or going to the bath-room! Cubs are born in the winter, usually 2 to 3 per littler, and stay with their mother for about two years.
Tiger Whiptail are only found along Colorado’s westernmost border in the desert regions along the Utah state line and into the four corners region. The lizard itself is typically around 4 inches long with a checkered or stripped pattern down its back that turns blue towards the tip of its tail. Adult males retain some of the blue coloring around their faces and bellies. They live in the lowland river valleys where pinion pine and juniper forests are most abundant. These lizards eat mainly bugs that can be found in or around dead leaves.
Bald Eagles are unique to North America and they are our largest bird of pray. They are our country’s national symbol and have been since 1782. They are named for their distinctive white head. Their head and tail feathers turn white around age 4. Their range once included the vast majority of the North American continent. They almost became extinct in the 20th century due to the introduction of pesticides and loss of habitat due to deforestation. Action was taken and the pesticide DDT was banned and habitats were protected. Since then, Bald Eagle populations have recovered and they are no longer on the endangered species list. They can be found nesting near reservoirs and along major rivers.
Mountain lions are Colorado’s largest cat, growing to more than 6 feet long and weighing 130 pounds or more as adults. They go by many names; cougar, puma, panther or catamount. They once roamed from coast to coast but today their numbers have fallen and they are mostly found in the western United States. In Colorado, they can be found in the foothills canyons and mesas. Immensely strong animals, they pounce on their prey, normally deer, and kill cleanly by braking the animals neck. Human encounters with mountain lions are on the rise as people continue to encroach on their habitats. If you meet a lion, stay calm and move slowly. Make yourself as large as possible and fight back if it attacks.
Mountain Blue Birds are known for their brilliant blue plumage. Males have a dark blue head and wings with lighter sky blue coloring on their chest, throat and belly. Females have gray-blue heads and wings with a gray chest and belly. The Mountain Blue Bird is mostly silent, but around dawn it lets out a soft warbling whistle. You can find the Mountain Blue Bird in orchards, around farmland and in mountain valleys. In lower elevations, they can be found year round. They hunt mostly in the air, snatching insects in flight. They will also forage on the ground. They eat grasshoppers, ants, bees and will also eat berries. They build their nest in tree cavities, rock crevices or holes in buildings laying 4 to 6 pale blue eggs.
The Colorado Cutthroat Trout is one of the three native cutthroat spices found in Colorado. Easily mistaken for a Rainbow Trout, the Colorado Cutthroat cab be identified by the red slash across its lower jaw. While not yet on the endangered species list, cutthroat trout are being carefully monitored as humans and invasive species reduce the range of these native fish. They can be found in the lake and streams of higher elevation areas west of the continental divide. Cutthroat prefer cold, clear and unobstructed waters. They spawn in the spring. Their growing season is short in higher elevations due to the cold water and they typically remain small in size, only 5 to 8inches long.
The Colorado Pikeminnow is an endangerd fish native to the Colorado River. It has a torpedo shaped body and a large mouth. It has been known to live up to 40 years and they once were known to grow as large as 6 feet long! Today, the average adult only reaches 2 to 3 feet long. They can be found in swift flowing rivers. Young Pikeminnows eat insects and plankton while larger adults eat smaller fish. Dams along the Colorado river and other diversion projects have limited the Pikeminnow’s habitat. The introduction of non-native species has also effected the Pikeminnow.
The Black-footed Ferret is one of the most endangered mammals in not only Colorado but in North America. They once ranged all over Colorado but today, they are on the brink of extinction. The last known Black-footed Ferret in Colorado was spotted in Buena Vista in 1943. Colorado Parks and Wildlife (CPW), the Utah Division of Wildlife Resources, the Bureau of Land Management (BLM), and the U.S. Fish and Wildlife Service (USFWS) are working to restore black-footed ferrets to their native range, which includes remote scrubland in Rio Blanco and Moffat counties in northwest Colorado.
The Kit Fox is a desert mammal found in the semi-desert shrub lands in Montrose and Mesa counties. They are the smallest fox in North America, weighing only 3 to 6 pounds. They live in family groups and are active at night when they leave their dens to hunt. It is an endangered species in Colorado. It was once hunted for its fur and todays human encroachment on its lands has limited its habitat. It has been on the protected species list since 1994.
The Long-nosed Leopard Lizard are large lizards with grey-black scales covered on small brown spots. During breeding season, females produce reddish-brown spots along their sides. Males are slightly smaller than the females. They are found in Garfield, Mesa, and Montezuma counties in the high deserts. Where they take up residence in abandoned rodent holes and eat insects and smaller lizards. They are listed as a species of special concern in Colorado.
The Humpback Chub is a member of the minnow family. It is green to silver and white with large hump behind the head. They grow to about 18 inches long. Similar to the Colorado Pikeminnow, the Chub’s calls the Colorado River home. They were once found from Wyoming to the Gulf of Mexico but today they are most likely to be found in the canyon regions of the Colorado River where the water is deep and fast moving. Dams along the Colorado river and other diversion projects have limited the Chub’s habitat. The introduction of non-native species has also effected the Chub.
The Burrowing Owl is a small bird with long legs and a flattened head. They have white eyebrows and large yellow eyes. Unlike most owls, you can see the Burrowing Owl during the day. They like to sit on fence-posts or on open ground around their habitat. Burrowing owls can dig their own burrows but they usually prefer burrows that have been dug by other small mammals such as prairie dogs, ground squirrels, and even badgers. They are on the state threatened list because their natural habitat is being developed for agriculture or other developments.
The River Otter is the longest of the weasel family, reaching lengths of 3 to 4 1/2 feet long. They have webbed toes to help push them thorough the water. Their fur is water-resistant allowing them to spend much of their life in the water. They were once found along the waterways statewide, but pollution and water diversion practices for irrigation caused their numbers to drop. In the 1970s, the Colorado Parks and Wildlife began to restore populations to several drainages, including the Upper Colorado, the Dolores and the upper South Platte rivers. The river otter’s status in Colorado was changed from endangered to threatened.
The Midget Faded Rattlesnake is found mainly in Mesa, Delta, and Garfield Counties. It prefers sandhills, semidesert shrubland, mountain shrubland, riparian zones, piñon-juniper woodland, and montane woodland s. They eat small mammals, lizards, birds and sometimes they will eat carrion when it is available. They shelter in crevices, woodpiles, brushy vegetation, or mammal burrows. The Midget Faded Rattlesnake hibernates in rodent burrows or in crevices in rock outcrops. They are listed as a species of special concern in Colorado.
The Peregrine Falcon is one of the fastest animals in the world. It can swoop down on its prey at speeds around 200 miles per hour! It is a medium sized falcon around 22 inches tall with a wingspan twice its body height. They can be found in open spaces with high cliffs and nearby rivers. They eat small rodents and small birds. They often hunt in pairs, teaming up on their pray. They nest on the cliffs or in cities, along the ledges of skyscrapers. They are listed as a species of special concern in Colorado.
The Gunnison Sage Grouse were historically found throughout the southwestern portion of Colorado and the southeastern Utah. The Gunnison Sage-grouse needs a range of habitats that includes grasslands and sagebrush. Sagebrush is a necessary part for sage-grouse because it provides both food and cover for the birds. They eat the leaves of the sagebrush as well as insects and other grasses. Gunnison sage-grouse inhabits only about 10 percent of their original range. They once ranged throughout Southwestern Colorado and into parts of Utah and New Mexico.
The Townsend’s Big Eared Bat has extraordinary ears. For a mammal who’s body only reaches 112 millimeters in length, its ears can reach up to 38 millimeters! They are very vulnerable to change and their numbers have been dropping as their habitat has been changed by humans and the environment. These bats can be found in mines, caves, and large rock cavities. When hibernating, the bats hang singly or in small clusters in the open. The Big Eared Bat feeds mainly on small moths, but also eats beetles, flies and wasps. They are listed on the state list of species of special concern.
The bighorn sheep is Colorado’s official state animal. There are two species of mountain sheep currently living in Colorado. The Rocky Mountain Bighorn is only found in the Rockies, preferring the extremely rugged terrain of the high mountains. Their massive curling horns are not shed like other horned animals but grow in length and circumference throughout their lifespan. They are listed as endangered on the Endangered Species Act. The desert bighorn was introduced to the Colorado National Monument in 1979. Around 230 sheep are know to call the Grand Valley home. Unlike their bigger cousins, desert sheep have adapted to the hotter, drier climate of the Grand Valley. They have longer legs and smaller bodies.
The New Zealand Mudsnail is an invasive freshwater snail that eat everything and breed quickly. They eat the food need by native species which effects the entire food chain in areas where they are introduced. People are the main carriers, though they may not know it. The snails attach themselves to waders, boots, boats, dogs and other gear and get carried to new bodies of water where they take over the ecosystem once again.
The Rusty crayfish is an aggressive freshwater crayfish from the Ohio River basin. They were brought to Colorado as fishing bait, got away and started to multiply. They eat small insects, fish eggs and water plants. This damages the underwater habitat of native species.
Waterfleas are zooplankton aquatic crustaceans that have a jumpy or jerky way of swimming. They are native to Africa, Asia and Australia. Unfortunately, they have been found in many waterways across Colorado. Once waterfleas are established, they are almost impossible to get rid of. Educating the public and following state watercraft inspection and decontamination policies are the best methods to contain current infestations and prevent their spread to new waters.
Zebra mussels are native to the Black, Caspian and Azov Seas of Eastern Europe. They are small freshwater mussels, related to clams and oysters. Like the New Zealand Mudsnail, they are an invasive freshwater snail that eat everything and breed quickly. Currently, there are no waters in Colorado that are positive for zebra mussels because steps have been taken to make sure they cannot get to our waters.
The Gypsy moth were introduced to the eastern states in the 1860s. They prefer hardwood forests such as apple, speckled alder, basswood, gray and river birch, hawthorn, oak, poplar, and willow. They become a nuisance as caterpillars, eating their way through their host plant. The caterpillar is hairy, growing 50- 65 mm long. The head of a mature caterpillar is yellow and black, with 5 pairs of blue spots on the abdomen and thorax. Behind the blue spots are 6 pairs of brick red spots. In Colorado, they are listed as one of the top Invasive Species Concerns and people should be on the lookout for them and report them if they are seen.
The Japanese beetle is a pest to hundreds of plant species. It is known to be one of the worst pests known in the eastern and Midwestern United States. In early July, adults can be seen feeding on vines, linden trees, roses, and many other ornamental plants. In Colorado, they are listed as one of the top Invasive Species Concerns and people should be on the lookout for them and report them if they are seen.
The Eurasian Collared Dove is a noisy bird that migrated here from the Bahamas, where it had been introduced by European settlers. They are aggressive towards native species and bully them away from feeding grounds. They are often mistaken for the native Mourning Dove. They can be identified by their loud shrieking sound and their dark ring of feathers around their necks.
The European Starling were released in New York City over a century ago and since then they have become one of the most common urban birds in the country. Starlings are aggressive towards other species. They drive other birds from fir nests and their feeding sites. They have been known to attack other animals as well, cats and dogs are often targets for these birds. The are commonly found in large groups. Their feathers are dark and glossy and they have long, pointed beaks.
The Norther Pike is an aggressive fish that can grow to 3 feet long and can weigh as much as 30 pounds. They are known by fishermen for their ability to destroy lures, leaders and even rods with their violent thrashing. They eat everything including other fish and are one of the main predators of Colorado’s native trout population.
Smallmouth bass, which were illegally introduced 5-10 years ago, have spread across the state. Because smallmouth bass are predators, they consume large numbers of endangered native fish. Like the Norther Pike and the Walleye, the Smallmouth bass is bringing native fish like the Colorado trout, ponytail, humpback chub, Colorado pikeminnow, and razorback sucker to the brink of extinction.
Walleye were introduced to Colorado in 1949 and since have multiplied and become a problem as they endanger native species. They can be identified by their two dorsal fins along their backs. They can grow as large as 18 pounds. Adults eat other fish including Colorado trout, ponytail, humpback chub, Colorado pikeminnow, and razorback sucker which are considered to be on the brink of extinction.
Goldfish are not a native species and are harmful to native ecosystems. Goldfish are small members of the carp family and are native to Asia. Goldfish are most commonly released to waters as discarded pets, classroom, or laboratory animals. Some goldfish escape outdoor ponds. Invasive fish species like goldfish can bring diseases to endemic species and they can also compete for resources. They have no natural predators, so they multiply unchecked.