Vigilance Behaviour in Barnacle Geese

This resource looks at the vigilance behaviour of barnacle geese grazing in winter. Throughout the winter young geese learn where best to feed and how to survive by foraging with their family groups. When an individual is foraging it has to balance the risk of feeding with the risk of possible predation. Gathering in flocks to feed gives an earlier warning of the approach of a suspected predator. Students investigate whether vigilance changes as a function of flock size and what other factors are likely to influence the behaviour of an individual, including social status, foraging efficiency and peripheral predation.

Through the activity, students consider the importance of defined categories of behaviour whilst recording the frequency and duration of defined behaviours. After a brief introduction to the migration of barnacle geese, the film shows twenty one sequences of one minute duration in which students must score the frequency and duration of ‘head-up’ (vigilant) postures in a target goose. The exercise highlights the trade-off between feeding and vigilance and the advantage of group feeding in reducing vigilance costs.

This resource was provided by the Association for the Study of Animal Behaviour (ASAB).