Answers are grounded in this paper and cite their sources.
Michael R. Conover, Don E. Miller, Reaction of Ring-Billed Gulls to Predators and Human Disturbances at at Their Breeding Colonies, Proceedings of the Colonial Waterbird Group, Vol. 2 (1979), pp. 41-47
No takes yet. Share an insight, caveat, or question.
Conover et al. (1979) studied this question.
Synapse has enriched 9 related papers. Consider them for comparative context: