Between the Herring Gull and the bulldozer

Abstract

Flock composition and interspecific dominance were studied in Black-headed Gulls and Herring Gulls wintering at an inland refuse dump in Germany. Herring Gulls were the dominant species and forced the much more numerous Black-headed Gulls to forage close to operating bulldozers. This supports the hypothesis that dominance governs the relationship between gulls feeding on refuse dumps and that this relationship is mediated through operating bulldozers favouring the smaller gull species.