Provisioning and prey quality in Brown Pelicans (Pelecanus occidentalis) in Charleston Harbor, South Carolina

I examined parent and nestling behavior during early chick rearing in Brown Pelicans (Pelecanus occidentalis) nesting at a colony in Charleston Harbor, South Carolina during the 2006 breeding season. There were significant differences in the frequency of feeding, attendance, and chick aggression according to chick age, although the pattern differed among behaviors. The rate of adult feeding, chick feeding and adult attendance all decreased with chick age while chick aggressive behavior peaked when chicks were ca. 21 d post-hatch. I found that nests with at least one juvenile parent had a lower average clutch size, hatch rate, and number of young that survived to 21 d than pairs with two adult parents. In addition to studying provisioning behavior, I also determined the proximate composition and energy density of seven species of marine forage fish that are potential prey items of Brown Pelicans and other seabirds on the coast of South Carolina. Some of these fish species are likely only available in the seabirds' diet as discarded bycatch from commercial shrimp operations. Proximate composition and energy density differed among the species of forage fish I examined. This suggests that piscivorous seabirds may experience differences in energy intake rates dependent upon prey availability. However, the range in energy density that I observed among species was relatively narrow and hence it appears that energy values in this region may be relatively stable among prey items during the seabird breeding season.