NAVARA, KJ; HILL, GE; MENDON�A, MT; Auburn University, Auburn, AL: Females Deposit More Yolk Androgens Into Eggs Sired By Less Attractive Males: A Contradiction To The Differential Allocation Hypothesis?

Female birds have been found to allocate androgens differentially within and among clutches, and it has been suggested that this is a strategy employed by those females to maximize reproductive success. We examined the potential factors contributing to the differential allocation of egg yolk content in the House Finch Carpodacus mexicanus, a sexually dichromatic passerine displaying high levels of hatching asynchrony. Male plumage color in this species is an honest signal of provisioning rate, and more attractive males tend to mate with better quality females. We found that female house finches deposit higher concentrations of yolk androgens into eggs sired by less attractive males. Additionally, overall, females deposited significantly more yolk androgens into eggs laid later in the clutch. However, when this pattern was examined in relation to mate attractiveness, the pattern only remained for eggs sired by less attractive males. Potential implications of these observed patterns will be discussed.