Foraging time allocation in relation to sex by the gulf coast fiddler crab (Uca panacea)

Summary

Schoener (1971) proposed that the reproductive demands of animals should be important in shaping their foraging behavior because fitness is affected. He defined two forager types: energy maximizers (reproductive success depends on energetic intake) and time minimizers (reproductive success depends on time spent in activities other than foraging), and suggested that females most often illustrate the former and males the latter. We tested whether mating activities influence the foraging behavior of Uca panacea, and the predictions that females would be energy maximizers because of their reproductive strategy and that males would also be energy maximizers because of their courtship activity. Time allocated to foraging by 800 male and female fiddler crabs (at two sites) was quantified; no significant difference in foraging time was found between the sexes. Both male and female crabs allotted a large portion of their time to foraging because both sexes depend on stored energy during their reproductive bouts. Our results show that the particular forager type can be predicted based on reproductive demands, but a forager type can not always be assigned to a particular sex without consideration of all important ecological and physiological factors determining reproductive success.