Vigilance Behaviour in White‐browed Sparrow‐weavers Plocepasser mahali

Group‐living white‐browed sparrow‐weavers engage in vigilance behaviour when fellow group members feed on the ground. Vigilance is characterized from normal perching behaviour by distinct combinations of calls and by exposed perches. The level of vigilance increases with the density of herbacious vegetation. Large groups do not perform less vigilance and more feeding compared with small groups, and are exposed to larger numbers of interactions with predators. This suggests that anti‐predator vigilance is an adaptation for surviving high diurnal predation rates, the latter being an effect of the group‐living nature of these birds.