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Honesty Of A Dynamic Female Aggressive Status Signal: Baseline Testosterone Relates To Bill Color In Female American Goldfinches, T T. Pham, Philip Queller, K A. Tarvin, Troy G. Murphy
Honesty Of A Dynamic Female Aggressive Status Signal: Baseline Testosterone Relates To Bill Color In Female American Goldfinches, T T. Pham, Philip Queller, K A. Tarvin, Troy G. Murphy
Biology Faculty Research
Status signals are linked to fighting ability and enable competitors to gain access to resources without risking injury in aggressive combat. The relationship between testosterone (T), a hormone that mediates aggression, and signals of status is well studied in males, but little is known about the relationship between T and female signals of status. Female and male American goldfinches Spinus tristis express a dynamic carotenoid-based orange bill color during the breeding season and previous work has demonstrated that females use orange bill color to communicate competitive ability during intrasexual competition. We test the hypothesis that female bill color reflects baseline …
Carotenoid-Based Ornaments Of Female And Male American Goldfinches (Spinus Tristis) Show Sex-Specific Correlations With Immune Function And Metabolic Rate, R. J. Kelly, Troy G. Murphy, K. A. Tarvin, G. Burness
Carotenoid-Based Ornaments Of Female And Male American Goldfinches (Spinus Tristis) Show Sex-Specific Correlations With Immune Function And Metabolic Rate, R. J. Kelly, Troy G. Murphy, K. A. Tarvin, G. Burness
Biology Faculty Research
Conspicuous ornamentation has been linked to immunological and physiological condition in males of many species. In species where both sexes are ornamented, it is unclear whether the signal content of ornaments differs between males and females. We examined the immunological and physiological correlates of carotenoid-based bill and plumage ornamentation in American goldfinches Spinus tristis, a species in which bright orange bills are sexually monomorphic but yellow plumage is sexually dimorphic during the breeding season. Because bill color is dynamic over short periods while plumage color is static over longer time frames, we tested whether these signals have the potential to …