Ecological correlates of feather mite prevalence in passerines

The relationship between host ecology and feather mite prevalence was analysed in birds. Feather mites are small arthropods (fam. Pterolichoidea and Analgoidea) commonly found on birds, although the nature of their interactions with the host (commensalism, mutualism or parasitism), still remains unclear. Host body mass and migratory behaviour were unrelated to feather mite prevalence. Contrary to expectation. there was no differences in mite prevalence between colonial and solitary-breeding species. However, winter sociality war associated with increased prevalence, suggesting that winter and breeding sociality affected the distribution patterns of feather mites in different ways. Plumage dichromatism was negatively correlated with feather mite prevalence. a result that is opposite to that predicted by the Hamilton and Zuk hypothesis for the evolution of host secondary sexual characteristics in relation to parasitism.