Document Type
Article
Journal/Book Title/Conference
Avian Biology Research
Volume
11
Issue
1
Publisher
Science Reviews 2000
Publication Date
2-2018
First Page
54
Last Page
61
Abstract
Nuptial plumage colouration is seemingly favoured by females of avian species with regards to sexual selection. This particular secondary sexual characteristic has been previously shown to be a condition-dependent signal of individual quality among passerines with pigment-based colouration (i.e. yellows and reds). In contrast, relationships between structural plumage colouration (i.e. blues) and aspects of both physical quality and physiological function have been understudied. Using free-living Indigo Buntings (Passerina cyanea) as a study species, we compared the percentage of blue feather coverage to body condition, innate immune responses, antioxidant capacity, stress physiology, reproductive physiology, and parasitism. We found the overall percentage of blue feathers on individual birds to be positively correlated with testosterone levels and body condition, while negatively correlated with heterophil to lymphocyte ratio. Birds with more blue coverage were also less likely to harbour blood parasites. Our results indicate male Indigo Buntings with greater moult investment have better overall body condition, lower stress, increased testosterone levels, and decreased parasitic susceptibility.
Recommended Citation
Hudson, Spencer B. and Wilcoxen, Travis E., "Condition-Dependence of Blue Plumage Coverage in Indigo Buntings Passerina cyanea" (2018). Biology Faculty Publications. Paper 1585.
https://digitalcommons.usu.edu/biology_facpub/1585