D.G. Smith J. W. Carpenter 1988 Cooperative efforts of the Canadian Wildlife Service (CWS), U.S. Fish and Wildlife Service (FWS), Wood Buffalo National Park in Canada, and Patuxent Wildlife Research Center have established a captive flock of whooping cranes, and at least two additional wild populations. Efforts have focused on research, habitat protection, law enforcement, and conservation education programs. application/pdf en Whooping crane recovery: Progress through research article