Attributes / relations provided by
♦ ¹Patterns of prey use by lesser scaup Aythya affinis (Aves) and diet overlap with fishes during spring migration, Kimberly A. Strand, Steven R. Chipps, Sharon N. Kahara, Kenneth F. Higgins, Spencer Vaa, Hydrobiologia (2008) 598:389–398
♦ 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.