In contrast, unpatterned models and patterned models that do not contrast with the background are less successful in eliciting escape responses of flies. Visual motion also significantly contributes to the successful flushing.
We show that contrasting patterns within the plumage are crucial to foraging success, as is contrast of the bird against a background. Elements tested were pivoting body movements, patterning on the spread tail and wings, and visual contrast of model redstarts against pale and dark backgrounds. Using models that decompose components of the redstart display, specific elements of the display were analyzed for their contribution in triggering visually induced escape behavior by dipterous insects. This account describes experiments showing that flush pursuit uses visual displays, which are likely to exploit an ancient neural circuit in dipteran insects, the visual systems of which are well documented as detecting looming stimuli and triggering an escape responses. Certain insectivorous birds, such as the painted redstart (Myioborus pictus), undertake flush pursuit – a characteristic display that elicits an escape reaction by an insect, which the bird then chases in the air and eats.