An Ethogram Identifies Behavioural Markers of Attention to Humans in European Herring Gulls (Larus argentatus)

Herring gulls are one of the few species that thrive in anthropogenic landscapes. Their longstanding history of urbanisation and familiarity with people makes them an excellent target for studies of the effects of urban living and cognition. Previous studies highlight a connection between food-stealing behaviour, success in anthropogenic areas and an increase in attention towards humans, opening up questions about the exact extent of a gull’s knowledge of human food cues and how this manifests itself in behavioural changes. To investigate these questions further, behavioural responses to human cues in a food-related context are investigated and presented in a systematic ethogram, which identifies three distinct markers of attention. Those behaviours – head turns, approaches, and the angular body position relative to the experimenter – differ significantly between control and food conditions, showing that attention towards humans in a food-related context is upregulated and this is reflected in the gull’s behaviour. In food condition trials, head turns occur more often and gulls face towards the experimenter (≤90°) with occasional approaches that are never seen in control conditions. Acoustic and behavioural human food-like cues alone were insufficient to elicit a response similar to that seen in presence of a real food item, indicating that gulls specifically pay attention to humans in foraging contexts. The results show situation-dependent attentional modulation in gulls, highlight knowledge gaps about how Herring gulls might identify food objects and provide an ethogram description of attentive behaviours that can be used in further study of attentional modulation in gulls.