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.
♦ ²Natural History of the South American Water Snake Helicops leopardinus (Colubridae: Hydropsini) in the Pantanal, Central Brazil, Robson W. Ávila, Vanda L. Ferreira and Janaína A. O. Arruda, Journal of Herpetology, Vol. 40, No. 2, pp. 274–279, 2006