A transactional analysis of changes in parent and chick behaviour prior to separation of Herring Gulls (Larus Argentatus): A three-term contingency model

•Changes in parent–offspring behaviour of urban Herring Gulls over time were studied.•Behavioural sequences were initiated by of a parental gull feeding the chick.•Over time, chicks’ begging became more intense, but parents often withheld food.•Chicks’ begging became directed at a wider range of adults over time.•These activities are placed within a three-term contingency model.•The model outlines behavioural processes involved in parent–offspring separation.

The effect of the passage of time on parent–offspring behaviour of urban Herring Gulls (Larus Argentatus) was studied and analysed using a three-term contingency model. A behavioural sequence was initiated by the arrival of a parental adult gull, which would lead to feeding in the chick. However, with the passage of time, and approach of the separation period, this pattern changed. Chicks’ begging became more intense, and parent gulls more often withheld food. However, the chicks’ begging became directed at a wider range of adults over the observation period. These activities are placed within a three-term contingency model, which may have implications for understanding some behavioural processes involved in parent–offspring separation.