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Wildlife Overview

Wildlife Overview

Fantastic for Wildlife

The City of Boulder's Open Space and Mountain Parks are some of the most diverse wildlife areas in all of Colorado, providing critical habitat for a variety of species. Boulder is unique among Front Range cities due to the preservation of the mosaic of ecosystems that form the foothills backdrop. Animal diversity tends to be higher in the low foothills of Open Space and Mountain Parks because of the mild climate and abundance of food and cover. A wide array of species inhabits Open Space and Mountain Parks, and their survival depends in part upon your actions while visiting their home. Please help us to keep our wildlife wild--do not approach or feed animals, and enjoy them from a respectful distance. By staying on designated trails, respecting trail/area closures, and following posted dog regulations, you can help us to preserve and protect critical wildlife habitat. Please familiarize yourself with Wildlife Watching Ethics to assure that the joy you feel observing and photographing wildlife doesn't come at their expense!


At least 59 mammal species have been documented on OSMP. The area provides a haven for many species as precious habitat shrinks with increasing development of surrounding areas. Several species of bats hibernate and roost in the area and help to keep insect populations in check. 

Some of our most frequently seen mammals include:

  • mule deer
  • golden-mantled ground squirrel
  • Colorado chipmunk
  • deer mouse
  • fox squirrel
  • pine squirrel
  • rock squirrel
  • striped skunk
  • raccoon
  • Abert's or tassel-eared squirrel 

Occasionally, visitors are fortunate enough to catch a glimpse of (or hear!) such species as:

  • coyote
  • red fox
  • white-tail deer
  • yellow-bellied marmot
  • long-tailed weasel
  • elk 
  • porcupine

Rarely seen are the secretive bobcat, mountain lion, and black bear.

Reptiles and Amphibians

OSMP is fortunate to have a good representation of "herptiles"--the reptiles and amphibians.

Our most well-known reptile is the venomous prairie rattlesnake. Although it is feared by many, the prairie rattlesnake is an important part of the food chain. The prairie rattlesnake is frequently confused with the harmless bullsnake, but the bullsnake does not have rattles and is generally larger. By mimicking the coloration and behavior of the rattlesnake, the bullsnake discourages predators. The beautiful (and harmless) milksnake is also present on OSMP; it sports red, black and yellow bands that resemble the colors of the venomous coral snake, but coral snakes are not found in Colorado.

Sawhill Ponds is a great place to glimpse turtles sunning themselves and provides marvelous habitat for OSMP's amphibians--the frogs, toads, and salamanders. 


More than 100 species of breeding birds have been reported on OSMP. Many of OSMP's bird species are migratory, flying northward from Mexico and Central America along the base of the mountains in the spring, and returning south in the fall. Many remain throughout the year, although some may move from plains to the mountains during breeding season.

Year-round residents include:

  • black-billed magpie
  • Steller's jay
  • mountain and black-capped chickadee
  • pygmy nuthatch
  • red- and white-breasted nuthatch
  • pine siskin
  • evening grosbeak
  • brown creeper
  • canyon wren
  • great horned owl
  • northern flicker
  • common raven
  • American robin
  • American crow
  • dark-eyed junco

Summer visitors include:

  • broad-tailed hummingbird
  • western wood-peewee
  • mountain bluebird
  • yellow-rumped warbler
  • western tanager
  • spotted towhee

Winter visitors include:

  • cedar waxwing
  • bald eagle
  • rough-legged hawk
  • ferruginous hawk


The insect world is incredibly rich and diverse. Here you will find the tiny Gaillardia Moth, an insect whose red head and yellow body match the colors of the gaillardia or blanket flower. The butterflies present in the summer bring as much color to the meadows and hillsides as the wildflowers. Look for Spring Azures, tiny radiantly blue butterflies that gather around puddles in early summer, making hikers wary of misplaced footsteps. The summer breezes are filled with orange and black checkered fritillaries, monarchs, and brown eye spotted wood nymphs, and yellow and black swallowtails soar in command of the air. As you hike on Chautauqua Meadow trails, watch for a praying mantis' slow but deliberate stalking of prey, spittle bugs froth on plant stems, and dragonflies patrolling clearings hoping to snatch a careless mosquito. Listen, too, for the sounds of cicadas filling a forest with their chatter. From jumbo bumble bees bullying their way into flowers to caterpillars building silken condos in the chokecherry bushes, the mysteries of Open Space and Mountain Parks insects await the curious and observant.

The state of Colorado is experiencing a mountain pine beetle epidemic that is killing a large percentage of mature lodgepole pines.  Beetle populations have dramatically increased in Boulder County and are killing lodgepole pines at the county's higher elevations. 

Give Them Some Space! Wildlife Watching Ethics on OSMP

Watching wildlife is a great way to enjoy nature and fun for people of all ages. But as you watch, remember that the animals may not enjoy it quite as much as you do.

Our natural urge is to get as close as possible. This is particularly true when you're trying to set up the perfect photograph. When a person tries to cautiously approach an animal, the animal may interpret the approach as a predator stalking its prey and become frightened. Humans should never disturb birds in their nests or mammals in their dens or with their young. OSMP seasonally closes certain parts of our land system to all users to protect breeding wildlife. 

Winter is a good time to watch wildlife, but bothering animals in the winter can be particularly harmful because they may expend energy that they need to survive the cold. Your car can be effective as a "blind" because animals may be accustomed to cars whereas they may become skittish if a person walks near them. Here are some suggestions on the proper way to watch wildlife:

Observe animals from a distance THEY consider safe.

  • Get your "close-up" by using binoculars, spotting scopes and telephoto camera lenses.
  • You are probably too close if animals are looking at you with heads up and ears pointed toward you; are nervous; or are "jumpy" when you move or make a noise. If you see these signs, sit quietly, or move slowly away until the behavior changes.
  • Move slowly and casually, not directly AT the wildlife.
  • Allow them to keep you in view, don't sneak up and surprise them.
  • Most animals rely on their eyesight and sense of smell to keep them from danger.

Never chase wildlife.

  • Don't follow them or behave in any way that might be seen as "harassment," which is unlawful.
  • Keep pets in your vehicle. 

Limit the time you spend with the animals.

  • Use the animals' behavior as a guide.
  • Please respect the space of others who may be viewing the same wildlife.