Sex and Age Bias in American White Pelicans Captured and Collected on Wintering Grounds

摘要

While conducting research examining the impact of American White Pelicans (Pelecanus erythrorhynchos) on the aquaculture industry in the southeastern United States, an apparent age and sex bias was observed among captured and collected pelicans. Data from 284 pelicans captured or collected at loafing sites located near aquaculture ponds during 1998 to 2009 were analyzed. A sampling bias could suggest segregation of pelicans by sex or age on wintering grounds. Captured pelicans were strongly biased towards immature males (73%) and collected pelicans were male biased (38% Adult Male, 47% Immature Male). Although the underlying mechanisms are not understood, observed pelican use of loafing areas may be related to numerous, readily available prey at aquaculture facilities. Received 21 December 2009, accepted 25 February 2010.