Endangered and Threatened Wildlife and Plants; Designation of Experimental Populations

We, the U.S. Fish Wildlife Service (Service), revise the regulations concerning experimental populations of endangered species and threatened species under the Endangered Species Act. We remove language generally restricting the introduction of experimental populations to only the species' "historical range" to allow for the introduction of populations into habitat outside of their historical range for conservation purposes. To provide for the conservation of certain species, we have concluded that it may be increasingly necessary and appropriate to establish experimental populations outside of their historical range if the species' habitat has undergone, is undergoing, or is anticipated to undergo irreversible decline and is no longer capable of supporting the species due to threats such as climate change or invasive species. We added language that the Secretary will also consider any adverse effects that may result to the ecosystem from the experimental population being established. We also made minor changes to clarify the existing regulations; these minor changes do not alter the substance or scope of the regulations.