Designated critical habitats for U.S. imperiled species are not protected from climate and land-use change

Designation of critical habitat is an important conservation tool for species listed as threatened or endangered under the United States (U.S.) Endangered Species Act (ESA). While this is an important protective mechanism, lands designated as critical habitat could still be subject to degradation and fragmentation if they are not also in a protected status that prioritizes biodiversity conservation. Additionally, most designations of critical habitat do not explicitly take climate change into account. The objective of our study was to determine whether and to what extent critical habitats for species listed under the ESA are located within protected areas and areas previously identified as climate refugia or climate corridors, to inform management strategies to better conserve and recover these species. We mapped the designated critical habitats of 153 ESA-listed species and measured their overlap with previously-identified areas of climate refugia and corridors (CRC), and also with lands designated as nature-protected by U.S. Geological Survey’s Gap Analysis Project (GAP Status 1 or 2) and working lands with wildlife habitat potential (GAP Status 3). Only 18 % of all designated critical habitat is located on lands that are both in CRC and nature-protected, and only 9 % of species had over half of their designated critical habitats in such lands. 84 % of species had <25 % overlap of their critical habitats with these areas. Critical habitats may therefore not fulfill their essential role of helping imperiled species persist and recover.