Attributes / relations provided by
♦ ¹del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona.
♦ ²An Ecological Survey of Endemic MOUNTAIN BEAVERS (Aplodontia rufa) in California, 1979-83, Dale T. Steele', State of California, THE RESOURCES AGENCY, Department of Fish and Game