The U.S. Fish and Wildlife Service and National Marine Fisheries Service have issued a final rule rescinding the regulatory definition of “harm” under the Endangered Species Act (ESA). The change is significant because the longstanding definition provided that prohibited “harm” could include significant habitat modification or degradation that kills or injures protected wildlife by impairing essential behavioral patterns, such as breeding, feeding, sheltering, spawning, rearing, or migrating. After the rule becomes effective, the agencies will instead apply the ESA’s statutory definition of “take” without a separate definition of “harm.”