Urban gulls distinguish perceived threats: Cognitive responses to human activities and their associated implements

Although urban-dwelling animals are able to access food, shelter, and breeding grounds in the towns and cities, they face potential dangers from humans and human modes of transportation. Consequently, the ability of animals to distinguish and promptly evade more threatening activities is essential to ensuring their survival. In this study, we compared the differences in the flight initiation distances (FIDs) of black-headed gulls (Chroicocephalus ridibundus) in Kunming City, southwest China, based on the differences in FIDs when approached by a boat and tools vs. a human. The results revealed that exhibited significantly different FIDs in response to distinct human‑activity modes, walking barehanded, carrying tools, or operating a boat, demonstrating their capacity for fine‑scaled, graded assessment of threats posed by humans and the human‑tool complex. These findings accordingly highlight that urban birds can dynamically integrate environmental cues, especially resource availability, for different types of risk assessment, underscoring the importance of considering species‑specific learning histories and local environmental reinforcement in urban ecology and management.