THE EFFECTS OF PREDATION RISK ON SCANNING AND FLOCKING BEHAVIOR IN DUNLIN

Dunlin (Calidris alpina) scanning and flocking behavior was studied in two habitats with different predation risk. Mean flock size, time spe nt scanning, and mean scan duration were higher in rice fields (dhe le ss profitable and high-risk habitat) than in littoral habitats (the mo re profitable and low-risk habitat), although vigilance rate was not d ifferent between habitats. Increased scanning and flocking behavior pr obably increase efficency in predator avoidance. The results are expla ined as behavioral changes to ensure safety in a high predation-risk s ituation when starvation risk is also present.