Index: Environment / Subcategory: Quality of Environment

Wildlife Species

Date Updated: 06/23/2011

With habitats ranging from grasslands to alpine slopes, Larimer County is home to a wide variety of wildlife species. According to the Colorado Division of Wildlife's Natural Diversity Information Source, 440 different species of amphibians, reptiles, birds, and mammals were 'known to occur' within the County about a decade ago, the latest such evaluation. Of these, 185 species commonly occur ('Abundance' categories: abundant; common; and fairly, locally or sparsely common).

The United States Fish and Wildlife Service administers the Endangered Species Act, which protects wildlife species that are in danger of becoming extinct. Through its Listing Program, the Service determines whether to add a species to the federal lists of endangered wildlife and plants. Once listed, a species is afforded the full range of protections available under the Endangered Species Act, including prohibitions on killing, harming or otherwise "taking" an organism from its habitat permanently. A species can be listed as either 'threatened' or 'endangered' under the Act. Most threatened species receive the same protections as endangered species, although exceptions are sometimes made, and it is possible to apply for a permit to 'take' a threatened species for research or other purposes.

The Colorado Division of Wildlife maintains a similar State Endangered Species List. Included on the list are species whose population within the state is threatened or endangered, but whose national populations may not be small enough to merit federal listing. The Division also lists species that are 'of concern.' Although there are no specific statutes prohibiting the harm of these species, 'species of concern' populations and habitats are monitored closely to ensure that the species do not become threatened.

What this chart shows: Commonly Occurring Species in Larimer County by Taxonomic Class, 2011

Data Source: Colorado Division of Wildlife - Natural Diversity Information Source

See data table

What these data tell us:

The Natural Diversity Information Source (NDIS) lists 102 different species of birds as 'abundant', 'common', 'fairly common' or 'locally common' to Larimer County. There are many more species of birds than any other taxonomic class. This is true of ecosystems in other locations as well. The small number of reptile and amphibian species is partly due to area climate. As a semi-arid area, Larimer County does not receive enough moisture to support a large number of amphibian species, and winter temperatures are too cold for many reptile species native to other areas.

The NDIS does not contain county occurrence data on fish species in Larimer County. The boundaries of water bodies do not conform to county boundaries; because of this, fish species are not studied in terms of county occurrence.

What this table shows: Wildlife Species Known to Occur in Larimer County by Federal or State Endangered Listing


Boreal Toad (SE)
Northern Leopard Frog (SC)


Midget Faded Rattlesnake (SC)
Common Garter Snake (SC)


Whooping Crane (FE, SE)
Least Tern (FE, SE)
Southwestern Willow Flycatcher (FE, SE)
Plains Sharp-tailed Grouse (SE)
Piping Plover (FT, ST)
Bald Eagle (ST)
Mexican Spotted Owl (FT, ST) [pdf]

Western Burrowing Owl (ST)

Greater Sandhill Crane (SC)
Ferruginous Hawk (SC)
American Peregrine Falcon (SC)
Western Snowy Plover (SC)
Mountain Plover (SC)
Sage Grouse (SC)
Long-Billed Curlew (SC)


Black-Footed Ferret (FE, SE)
Preble's Meadow Jumping Mouse (FT, ST) [pdf]
Lynx (FT, SE)
Wolverine (SE)
Northern River Otter (ST)
Townsend's Big-eared Bat (SC)
Black-Tailed Prairie Dog (SC)
Northern Pocket Gopher (SC)
Swift Fox (SC)


FE: Federal Endangered List
FT: Federal Threatened List
SE: State Endangered List
ST: State Threatened List
SC: State Concern List

Data Source: Colorado Division of Wildlife - Natural Diversity Information Source

What these data tell us:

Of the federal endangered species known to have occurred in Larimer County, one, the Black-Footed Ferret, has been extirpated (extinct locally) from the area since the 1950s. Of the species on the State Endangered List, one species, the Boreal Toad, is listed by the Natural Diversity Information Source as 'common' to Larimer County. On the State Concern List, two species of mammals, the Northern Pocket Gopher and the Black-Tailed Prairie Dog, are common to Larimer County. Aside from the eight bird species 'known to occur' in Larimer County provided federal protection, an additional nine bird species are on the three state lists.

The Burrowing Wwl, also known as the Western Burrowing Owl, which is listed by the Natural Diversity Information Source as 'fairly common' to Larimer County, has been added to the State Threatened List since 2004, and the Bald Eagle has been dropped from the Federal Threatened List, but remains on the State Threatened List.

Species can become endangered or threatened for a variety of reasons. Causes of endangerment include destruction of habitat, competition from non-native species, overhunting and overfishing, disease, and pollution.

Click on species names for additional information about specific species.

Additional Information:

Related Information on COMPASS -

Other Resources:

Industry Standards or Targets:


Data Table:

Commonly Occurring Species in Larimer County by Taxonomic Class

Taxonomic Class

Number of Species









See chart