Dark habitats and bright birds: Warblers may use wing patches to flush prey

Studies of bird plumage coloration strongly influence evolutionary and ecological theories, that concern various types of signalling behavior, One theory often overlooked by researchers studying plumage coloration is the prey flushing hypothesis (PFH). Scientists did not consider the PFH even when their data might have been used to test it. For example, if the PFH had been taken into account by Marchetti (Nature 362: 149-152, 1993) in the study of the role of plumage patches in territorial defence, the interpretation of the data might have changed. In this note I explain why the PFH must be taken seriously into consideration in studies of signalling behavior in birds. I do so by reexamining Marchetti's study and by looking for evidence supporting the PFH in several other papers.