SEARCHING FOR CONSPICUOUS VERSUS CRYPTIC PREY: SEARCH RATES OF FLUSH-PURSUING VERSUS SUBSTRATE-GLEANING BIRDS

Abstract

Abstract Models predict that predators of cryptic prey should have a moderate or low search rate because at high search rates only a small proportion of cryptic prey is detected. Predators of conspicuous prey should have fast search rates because their prey are easily detectable. For a large difference in conspicuousness, this prediction is not affected by differences in prey characteristics. Substrate-gleaning birds rely upon searching for cryptic and largely immobile prey. Painted Redstarts (Myioborus pictus) use flashy pivoting body movements of a spread tail and wings to flush prey into the air, making the prey highly conspicuous. The birds then chase the prey in aerial pursuits (flush-pursue foraging). Using field observations of birds in the Chiricahua Mountains, Arizona, and using literature I show that differences in search rates between flush-pursue foragers and insectivorous substrate-gleaning foragers are consistent with the theoretical predictions. Busqueda de Presas Conspicuas versus Presas C...