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.
♦ 2BirdLife International (2012) Species factsheet:
Branta ruficollis. Downloaded from http://www.birdlife.org on 06/09/2012.