Behavior and Ethology Commons^™

Glare Reduction By Dark Facial Markings And Bills In Birds, Clara Lebow

Electronic Theses and Dissertations

Avian facial plumage, bill coloration, and feather microstructure may serve one or more adaptive functions. Several researchers have proposed that dark eyestripes, bills, and facial masks aid in reducing glare, however, there have been relatively few tests of this hypothesis. Dark facial markings have been shown to have an adaptive glare-reduction function in recent field studies of a few species, but this hypothesis has never been tested in a broad multispecies analysis. It is likely that feather microstructure influences feather brightness and has an effect on the efficacy of glare reduction properties of feathers. I examined the link between dark …