Endangered Species
Ecological Services

Listing and Critical Habitat | Critical Habitat

Photo of Ash Meadows NWR by Mike Bender, USFWS

Ash Meadows National Wildlife Refuge in Nevada provides critical habitat for eight threatened or endangered species.

Photo credit: Mike Bender, USFWS

When a species is proposed for listing as endangered or threatened under the Endangered Species Act, the Service must consider whether there are areas of habitat believed to be essential to the species' conservation. Those areas may be proposed for designation as "critical habitat." The determination and designation of critical habitat is one of the most controversial and confusing aspects of the ESA.

If critical habitat is designated, does that mean no further development can occur?
No. A critical habitat designation does not necessarily restrict further development. It is a reminder to Federal agencies that they must make special efforts to protect the important characteristics of these areas.

Does a critical habitat designation affect all activities that occur within the designated area?
No. Only activities that involve a Federal permit, license, or funding, and are likely to destroy or adversely modify the area of critical habitat will be affected. If this is the case, we will work with the Federal agency and, where appropriate, private or other landowners to amend their project to allow it to proceed without adversely affecting the critical habitat. Thus, most Federal projects are likely to go forward, but some will be modified to minimize harm to critical habitat.

Find answers to other frequently asked questions regarding critical habitats.

Learn how many species have been designated with critical habitats by the Service or NOAA (also known as NMFS).

Access an online mapping application that displays designated spatial information for selected critical habitats.

View the status of critical habitat actions (historical logs of the actions that propose, finalize, withdraw or change critical habitat designations for a species) within a specified date range.

Last updated: July 15, 2013