. . . . . . . "1981-01-01T00:00:00Z"^^ . . "Anas americana" . . "Tracheophyta" . . "Saunders, G.B. and D.C. Saunders. 1981. Waterfowl and their wintering grounds in Mexico, 1937-1964. U S Fish and Wildlife Service Resource Publication 138." . . . . "Allen Hurlbert. 2017. Avian Diet Database." .