Meeting Abstract
Bright plumage coloration is seemingly favored by females of avian species with regards to sexual selection. This particular secondary sexual characteristic has been previously tested and supported to be an honest signal of individual quality among passerines with pigment-based coloration (i.e. yellows and reds). In contrast, structural plumage coloration (i.e. blues) exhibited by birds such as Indigo Buntings (Passerina cyanea), have received minimal research on relationships between plumage color intensity and aspects of physiological function. Using free-living Indigo Buntings as a study species, we compared UV and blue color intensity to innate immune responses, antioxidant capacity, and stress physiology. UV or blue coloration of the tail feathers was not correlated with any of the physiological metrics. The overall percentage of blue feathers on individual birds was positively correlated with body condition and negatively correlated with heterophil to lymphocyte ratio, indicating that the overall blueness of male Indigo Buntings is associated with better body condition and lower stress.
