Welcome to the American Ornithological Society 2018 Annual Conference. We are pleased to have you join us at the lovely Hilton El Conquistador Resort in Tucson, AZ.
Woodpeckers are diverse group of birds distributed across most of the globe. The 230 species exhibit a dizzying range of plumage colors and patterns. What drives species to look the way they do? How are species' plumages shaped by the habitats and climate conditions they encounter? Moreover, there appear to be a number of remarkable cases of plumage convergence between rather distantly related woodpeckers. Downy and Hairy Woodpeckers, for example, are separated by approximately 6.5 million years of evolution; each is more closely related to quite dissimilar looking species than they are to one another. What has caused these remarkable convergences in woodpecker plumage? We measured the plumage of all woodpecker species, and quantified to what degree habitat, climatic, genetic, and social interactions have acted in concert to shape woodpecker colors and patterns. We found that all of these factors are relevant in shaping the way species look. In accordance with Gloger's rule, species are darker in more humid regions. They are also less patterned in such areas. Woodpeckers are brighter and more heavily marked in open, arid, and seasonal environments. Moreover, certain species pairs appear to have converged in plumage above and beyond what would be expected based on shared evolutionary history, habitat, and climatic preferences alone. We identify a number of such pairs (and trios), and propose that these remarkable instances of apparent mimicry are driven by the benefit to smaller species of fooling third parties into relinquishing resources they would otherwise be able to defend.
