The effect of group size on standing , walking , sleeping and foraging behaviours of black - winged stilts ( Himantopus h . leucocephalus )

Group size in an imperative factor in determining an individual’s behavioural actions and applies to all organisms in the animal kingdom. Different group sizes come with varying benefits and threats forcing the animal to accept them or find a group size that suits its needs. Behaviours, such as, standing, walking, sleeping and foraging are a part of shorebirds’ daily routine, yet the frequencies of their occurrence visibly vary with the group size of the flock. This study statistically investigates the differences of frequencies of such behaviours in black-winged stilts as a response to group size. The analysis revealed that individual birds spent less time standing than birds in groups, and that the percent of birds sleeping and the number of birds in a group had the strongest linear relation. Additionally, as the group size increased, the dominant behaviour changed from walking to standing to sleeping. The findings of this article are merely the beginning of uncovering the depth of the impact that group size has upon pied stilts’ behaviours and should be further expanded.