Endangered Species
Ecological Services

Listing and Critical Habitat | Critical Habitat | Frequently Asked Questions

Photo of San Joaquin kit foxes by B. Moose Peterson, WRP

San Joaquin kit foxes (Vulpes macrotis mutica)

Photo credit: B. Moose Peterson, WRP

What is critical habitat?
Critical habitat is a term defined and used in the Endangered Species Act. It is specific geographic areas that contain features essential to the conservation of an endangered or threatened species and that may require special management and protection. Critical habitat may also include areas that are not currently occupied by the species but will be needed for its recovery.

What steps are involved in a designation of critical habitat for a species?
We follow a strict legal process known as a rulemaking (or regulatory) procedure. Federal agencies follow this procedure to propose and adopt regulations that have the effect of law and apply to all persons and agencies under U.S. jurisdiction.

We publish proposals to designate critical habitat in the Federal Register, a daily publication of the Federal Government. We consider all information received during the public comment period and may refine our final designation based on this information. We then publish a rule finalizing the critical habitat designation.

How does the Service determine what areas to designate as critical habitat?
Within areas occupied by the species, biologists consider physical or biological features needed for life processes.

These include:

  • space for individual and population growth and for normal behavior;
  • cover or shelter;
  • food, water, air, light, minerals, or other nutritional or physiological requirements;
  • sites for breeding and rearing offspring; and
  • habitats that are protected from disturbances or are representative of the historical geographical and ecological distributions of a species.

Biologists also consider unoccupied areas that are essential for the conservation of the species.

The areas shown on critical habitat maps are often large. Are all the areas within the mapped boundaries considered critical habitat?
No. Service rules normally exclude by text developed areas such as buildings, roads, airports, parking lots, piers, and other such facilities.

How many species have critical habitat designations?
As of August 2021, critical habitat has been designated for 764 of the more than 1,600 U.S. species listed as endangered or threatened.


Last updated: August 2, 2021