Meeting Abstract

P2.104  Friday, Jan. 4  Flashy feet: color based assortative mating in the black guillemot (Cepphus grylle) CARLTON, E.D.*; STEWART, S.N.; HAUSSMANN, M.F.; MAUCK, R.A.; Kenyon College, Gambier OH; Kenyon College, Gambier OH; Kenyon College, Gambier OH; Kenyon College, Gambier OH and Bowdoin College, Brunswick ME haussmannm@kenyon.edu

Competition for limited mates and resources has resulted in a wide array of morphological ornamentations that reflect the bearer�s genetic and physiological superiority over that of their less-decorated counterparts. Aerobic metabolism produces reactive oxygen species that damage DNA, lipids, and proteins. Cells utilize a variety of defenses�including dietary carotenoids and cellular-made catalase�to neutralize the consequences of this process. However, because carotenoids can also be allocated to pigmentation, a trade-off exists between maintaining ornamentation and boosting antioxidant defense. The black guillemot (Cepphus grylle), a monomorphic seabird, is characterized by its red feet. We propose that foot redness may influence assortative mating and is an honest signal of oxidative stress. To test this, we photographed the right foot and collected a blood sample from each member of 16 incubating pairs of C. grylle during the 2007 breeding season on Kent Island, New Brunswick, Canada. We used spectrophotometric assays to measure erythrocyte catalase and plasma antioxidant concentrations. Randomization tests revealed that foot color is highly correlated between mates of unknown sex (95% C.I. of slope = 0.30-0.78). However, we found no relationship between foot redness and antioxidants. These results indicate that C. grylle mates assortatively based on foot color, but the lack of correlation between color and antioxidant measures suggests that foot redness is an honest signal of a different aspect of quality. Molecular sexing should allow us to more clearly determine the role of sex in this assortative mating system.