European Herring Gull (Larus argentatus) Science Article 11
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 ismediated through operating bulldozers favouring the smaller gull species.
J. Bellebaum, Ornis Fennica 82:166-171. 2005