Individual variation in mate preference in great tits (Parus major)

When individuals have the same preference for mates, variation within the population should decrease, known as the ‘lekparadox’. Resolution of the lek paradox has been attempted by considering fluctuating selection, condition dependence of the signal, as well as mate choice for non-additive genetic benefits, but the possible role of individual differences in matechoice is severely underexplored. Variation in mate preferences may weaken the strong directional selection on ornaments and thereby allow diversity to persist. Here we tested for individual differences in great tit mate preferences, and whether these preferences vary depending on the chooser’s own traits, since this would affect the relative benefit of complementary traits in their partner. In great tits, as in numerous passerine species, both males and females are ornamented and invest heavily in reproduction. They both display multiple ornaments primarily relating to dominance (breast stripe) and parental care (yellow plumage). We expected that not only the females, but both sexes would display mate preferences. Using a 6 choice test 29 female and 30 male great tits were tested for their mate preference. Preference functions were calculated for a number of traits such as breast stripe size, intensity of yellow breast feathers and personality. Here we describe the individual mate preferences in relation to the choosers own phenotype.