MHC-mediated sexual selection on bird song: generic polymorphism, particular alleles and acoustic signals

Several hypotheses predict that the major histocompatibility complex (MHC) drives mating preference in females. Olfactory, color or morphological traits are often found as reliable signals of the MHC profile, but the role of avian song mediating MHC-based female choice remains largely unexplored. We investigated the relationship between several MHC and acoustic features in the collared flycatcher (Ficedula albicollis) a European passerine with complex songs. We screened a fragment of the class IIB 2nd exon of the MHC molecule, of which individuals harbor 4-15 alleles, while considerable sequence diversity is maintained at the population level. To make statistical inferences from a large number of comparisons, we adopted both null-hypothesis testing and effect size framework in combination with randomization procedures. After controlling for potential confounding factors, neither MHC allelic diversity nor the presence of particular alleles was associated remarkably to the investigated qu...