Possible relationships between morphology, territoryquality, and skin color of American Kestrels

Carotenoid-based coloration of skin and plumage has been found to be correlated with individualquality in many species of birds during the breeding season. However, less is known about the possible role of thesesignals during the nonbreeding season, particularly among nonpasserines that defend winter territories. AmericanKestrels (Falco sparverius) are sexually dimorphic raptors that defend winter territories and possess carotenoid-basedmorphological features known to be correlated with individual quality.Much is known about winter territory use andhabitat segregation by male and female kestrels, but possible relationships among morphological features, individualquality, and habitat quality have not been examined. Our objective was to examine possible relationships betweenmorphology, territory quality, and skin color of American Kestrels

Mark R. Bostrom and Gary Ritchison, J. Field Ornithol. 77(4):392-398, 2006