Attributes / relations provided by
♦ 1FEEDING ECOLOGY OF PINTAIL HENS DURING REPRODUCTION, GARY L. KRAPU, The Auk 91: 278-290. April 1974
♦ 2del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.).
Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona.