Meeting Abstract
The maintenance of female limited polymorphism in species where some, but not all, of female morphs are Batesian mimics is puzzling because it is unclear what selective pressures drive the maintenance of the non-mimetic female form. Three current hypotheses are that the non-mimetic form is maintained as a result of sexual selection (mate preference for the non-mimetic form), life-history trade-offs (non-mimetic females produce more offspring than mimetic females) or frequency dependent selection (mimetic forms incur increasing fitness costs with increasing frequency). Here we test the sexual selection hypothesis by conducting a series of group choice, individual choice, and no-choice male preference assays in the butterfly Papilio polytes. We find that males exhibit a preference for mimetic over non-mimetic females, and that this preference does not change throughout an individual’s lifespan, suggesting that male preference for non-mimetic females is not driving the maintenance of female polymorphism. However, males who experienced unsuccessful courtship attempts with mimetic females were observed to then court non-mimetic females, even when given a choice of a mimetic and a non-mimetic female. Unsuccessful courtship was associated with this switch throughout male lifetime: the more often a male engaged in courtship, the more likely he was to have courted both mimetic and non-mimetic forms. These results suggest that, though males prefer mimetic over non-mimetic females, male receptivity of non-mimetic females may change over time. Thus, change in male receptivity has the potential to facilitate the maintenance of the non-mimetic female morph.
