Parasites and bright birds: new data and a new prediction

Presents the results of a comparative study of haematozoa of tropical Central and South American birds and discusses the value of such studies for critically evaluating the Hamilton and Zuk hypothesis. The tropical data set allowed the study of a much larger sample (526 species) than had previously been examined, and one containing many of the gaudy birds found in tropical habitats. Use of tropical birds allowed comparison between migrant and resident species; because the Hamilton-Zuk hypothesis requires that parasites coevolve closely with their hosts, resident species should show the relationship between brightness and parasite level more strongly than migrant species, which are more likely to be exposed to different sets of haematozoa in wintering and breeding habitats. The confounding effect of phylogeny must be dealt with, ie certain groups of species may show the association between brightness and infection level merely because of shared ancestry. -from Author