Meeting Abstract

62.2  Sunday, Jan. 5 13:45  Are more ornamented birds better at combatting disease? Assessing the links between condition and ornamentation. STALEY, M*; BONNEAUD, C; HILL, GE ; Auburn University; University of Exeter; Auburn University mms0020@auburn.edu

Condition is enigmatic. The concept of condition permeates the behavioral and physiological literature but exactly what it means for an individual to have high or low condition is poorly understood. Recently, condition was defined as the functionality of vital cellular processes, such that poor condition compromises the ability of an individual both to produce ornamentation and to perform well in maintenance tasks such as immune defense. In house finches (Haemorhous mexicanus), carotenoid-based plumage coloration in males is widely recognized as an indicator of condition. Our goal was to test the hypothesis that, because ornamentation and immune defense are both dependent on individual condition, plumage coloration would predict the ability of male house finches to resist infection by the bacterial pathogen Mycoplasma gallisepticum (MG). We collected male house finches from a population in Arizona that had no exposure history with MG, brought them to Auburn University, and experimentally inoculated them with MG. All finches showed symptoms of mycoplasmosis by 14 days post inoculation, at which time we euthanized all birds and collected tissues. We quantified the degree of bacterial proliferation in the conjunctiva tissue of infected birds with quantitative PCR. We then compared the feather color of birds (recorded at the time of capture) to the bacteria load. By studying this relationship between plumage coloration and individual performance in dealing with a pathogen in wild-caught birds, we can gain new insights into the role of condition in individual performance.