The painted redstart [Myioborus pictus L.] search rate of a cryptic versus conspicuous prey: a field test of optimal search models

Models of optimal search rates predict that predators increase the search rate when availability of conspicuous prey increases relative to cryptic prey. I tested this prediction by comparing foraging hop rates by 19 Painted Redstarts (Myioborus pictus) - insectivorous birds in Arizona, USA. Redstarts often use flashy displays of open wings and tail to flush their prey and to subsequently chase the prey in air. Such flush-displays make the prey conspicuous and easy to detect. Hence, foraging mode affects relative availability of conspicuous versus cryptic prey: birds foraging with frequent flush-displays encounter conspicuous prey more often then birds foraging with infrequent flush-displays. As predicted, the hop rates during foraging with infrequent flush-displays were lower than hop rates during foraging with frequent displays.