The Department of Fish and Wildlife (FWS) has exterminated 450 barred owls since 2013 as part of an experimental program meant to aid in the recovery of the northern spotted owl. The FWS hoped that by removing barred owls that are encroaching on spotted owl habitat and taking it over, northern spotted owl numbers would begin to improve. Two animal rights groups sued the FWS a year later in 2014, alleging the agency violated the National Environmental Policy Act and Migratory Bird Treaty Act by killing barred owls.