 Great white pelicans on Dyer Island, in the Western Cape region of South Africa, were culled during the 19th century because their predation of the eggs and chicks of guano-producing seabirds was seen to threaten the livelihood of the guano collectors.More recently, such predation at South African seabird colonies has impacted on the conservation of threatened seabird populations, especially crowned cormorants, Cape cormorants, and bank cormorants.This has led to suggestions that pelican numbers should be controlled at vulnerable colonies.