Kays, along with fellow curator Robert Feranec, developed a new kind of carbon isotope test on hair and bone that proved the Sacandaga Lake wolf lived on a diet in the wild, and had never been a pet or zoo specimen fed by humans. Seeing the animal was not a coyote, the hunter gave the wolf carcass to the state Department of Environmental Conservation, which called in federal wildlife officials, who confiscated it. The DEC issued a statement saying the study shows federal U.S. Fish and Wildlife Service officials need to reverse efforts to remove endangered species protections for wolves in the Northeast. Said Christopher Amato, assistant commissioner for natural resources, "We continue to believe that natural recovery of wolves in the Northeast is possible and urge the U.S. Fish and Wildlife Service to reconsider its recent proposals and to update its wolf recovery plan to reflect this new scientific information and support the natural recolonization by wolves." In July 2004, federal officials proposed removing the wolf from the endangered species in the east, due to growing wolf populations from recovery efforts in Minnesota, Wisconsin and Michigan.