FWS will finalize a proposal to revise the regulations at 50 CFR 17.80 through 17.83 concerning experimental populations of endangered species and threatened species under the Endangered Species Act (ESA). If finalized as proposed, FWS will 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 ability of the habitat to support one or more life history stages has been reduced due to threats such as climate change or invasive species. FWS will also make minor changes to clarify the existing regulations. These minor changes are not intended to alter the substance or scope of the regulations.