Brown Booby (Sula leucogaster) Science Article 1
Sex differences in the foraging behaviour of adults have been observed in a number ofsexually size-dimorphic birds, and the usual inference has been that these sex-specificdifferences are driven primarily by differences in body size. An alternative explanation is thatforaging differences result from sex differences unrelated to size, such as sex-specific nutritionalrequirements. To examine these alternative hypotheses, the foraging behaviour ofparents was compared between two sympatric and congeneric species of seabird, the BrownBoobySula leucogaster, which is highly sexually size-dimorphic (females 38% larger) andthe Red-footed BoobyS. sula, in which sex differences in body size are less marked (females15% larger).
SUE LEWIS et al., Ibis (2005), 147, 408-414