Agnonistic behavior in short-billed dowitchers feeding on a patchy resource

Abstract

In this paper we describe an instance of unusual, agonistic behavior in a flock of migrant Short-billed Dowitchers ( Limnodromus griseus ) . We compare this behavior to that of other flocks feeding at the same time at other locations in the same estuary and then present evidence suggesting that this behavior resulted from the patchy distribution of the probable foraging resource of this flock, eggs of the horseshoe crab ( Limulus polyphemus ). We propose that an extremely patchy resource has increased the agonistic behavior within the flock by increasing the variation in foraging success among individuals.