Ecological correlates of feather mite prevalence in passerines

The relationship between host ecology and feather mite prevalence was analy sed in birds. Feather mites are small arthropods (fam. Pterolichoidea and A nalgoidea) commonly found on birds, although the nature of their interactio ns with the host (commensalism, mutualism or parasitism), still remains unc lear. Host body mass and migratory behaviour were unrelated to feather mite prevalence. Contrary to expectation. there was no differences in mite prev alence between colonial and solitary-breeding species. However, winter soci ality war associated with increased prevalence, suggesting that winter and breeding sociality affected the distribution patterns of feather mites in d ifferent ways. Plumage dichromatism was negatively correlated with feather mite prevalence. a result that is opposite to that predicted by the Hamilto n and Zuk hypothesis for the evolution of host secondary sexual characteris tics in relation to parasitism.