Nutrient utilization by and diet preference of American white pelicans when offered diets of channel catfish and(or) grass carp.

摘要

Twelve pelicans captured in northeast Mississippi were used for a 7 day metabolism trial followed by a 2 day preference trial and a trial to evaluate the effect of consuming plastic tags. In the metabolism trial, pelicans were allotted to one of three treatment diets (4 birds/diet): catfish only, carp only or both (50 % catfish and 50% carp). Pelicans consuming the catfish only diet metabolized less dry matter, organic matter and energy than those consuming only carp or both. Four pelicans were used to determine preference for carp or catfish. Pelicans ate more (P = 0.001) carp (89 % of diet) and digested nutrients from carp more efficiently than they did from catfish. Plastic tags were attached to numerous fish fed to pelicans in the preference trial, which were regurgitated or retained by pelicans, with no effect on the plastic tags by digestion.;Key words: pelicans, metabolism, preference