Foraging behaviour of the Peaceful Dove (Geopelia striata) in relation to predation risk: group size and predator cues in a natural environment

Abstract

Foraging behaviour is directly influenced by the risk of predation, which is in turn influenced by distance to cover, height of vegetation and predator cues. In this study, we used giving-up density (GUD) to investigate the foraging behaviour of the Peaceful Dove (Geopelia striata) in relation to predation risk. We simulated predation risk by placing feeding patches in grass of various heights, and visual and auditory predator cues were also simulated. GUD was higher near tall grass and minimum GUD of individuals remained similar among different group sizes. Both visual cues and the combination of visual and acoustic cues altered the patterns of GUD significantly, but the effects of the two treatments did not differ from each other. We conclude that changes in vegetation structure and visual predator cues can strongly increase the assessment of predation risk by ground-feeding birds. Grouping behaviour in this species was not entirely a result of clumped food resources in their natural environment but was influenced by anti-predator strategies and birds could maintain higher food intake in more dangerous places when in groups. Our study used a rare, but important, field experimental approach to determine factors that affect foraging behaviour in a bird.