FORAGING STRATEGY AND PREDATOR AVOIDANCE-BEHAVIOR - AN INTRASPECIFIC APPROACH

Relationships between predator avoidance behaviour (scanning and flock ing) and foraging were studied in Calidris alpina, to test predictions regarding the effect of foraging techniques on such behaviours. The s canning hypothesis predicts that individuals with a tactile hunting te chnique and individuals with a visual hunting technique (both continuo us searchers) do not differ in any variable related to scanning behavi our The flocking hypothesis predicts that visually hunting individuals will tend to form smaller flocks than tactile-foraging individuals. T he two continuous feeding strategies did not differ among individuals in vigilance rate, nor in vigilance time or mean scan duration. Howeve r, with respect to flocking behaviour, visual foragers differed from t actile foragers in foraging flock size. The relationships between floc king behaviour and foraging strategy are discussed. The pattern found at the intraspecific level are the same as those found at interspecifi c level.