Vigilance (behavioural ecology)

Vigilance, in the field of behavioural ecology, refers to an animal's monitoring of its surroundings in order to heighten awareness of predator presence. Vigilance is an important behaviour during foraging as animals must often venture away from the safety of shelter to find food. However, being vigilant comes at the expense of time spent feeding, so there is a trade-off between the two. The length of time animals devote to vigilance is dependent on many factors including predation risk and hunger.

Vigilance is often observed in animals that forage in groups, such as yellow-eyed juncos (Junco phaeonutus) and meerkats (Suricata suricatta). Foraging in groups dilutes an individual's risk of predation, and allows them to reduce their own vigilance while the vigilance of the group is maintained.^[1] Alarm signals may be used to alert the group to the presence of predators. Groups of some species have at least one individual on sentry duty who looks out for predators on a perch while the rest of the group forages.^[1]