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.
♦ ²Estimated Fish Consumption by Hooded Seals (Cystophora cristata), in the Gulf of St. Lawrence, M. O. Hammill, C. Lydersen, K. M. Kovacs and B. Sjare, J. Northw. Atl. Fish. Sci., Vol. 22: 249–257 (1997)