Attributes / relations provided by
♦ ¹Åge Brabrand, Food of roach (Rutilus rutilus) and ide (Leusiscus idus): significance of diet shift for interspecific competition in omnivorous fishes, Oecologia Volume 66, Number 4 (1985), 461-467
♦ 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.