title: Resource predictability and specialization in avian malaria parasites.
abstract: We tested the hypothesis that avian haemosporidian (malaria) parasites specialize on hosts that can be characterized as predictable resources at a site in Amazonian Ecuador. We incorporated host phylogenetic relationship and relative abundance in assessing parasite specialization, and we examined associations between parasite specialization and three host characteristics - abundance, mass and longevity - using quantile regression, phylogenetic logistic regression and t-tests. Hosts of specialist malaria parasite lineages were on average more abundant than hosts of generalist parasite lineages, but the relationship between host abundance and parasite specialization was not consistent across analyses. We also found support for a positive association between parasite specialization and host longevity, but this also was not consistent across analyses. Nonetheless, our findings suggest that the predictability of a host resource may play a role in the evolution of specialization. However, we also discuss two alternative explanations to the resource predictability hypothesis for specialization: (i) that interspecific interactions among the parasites themselves might constrain some parasites to a specialist strategy, and (ii) that frequent encounters with multiple host species, mediated by blood-sucking insects, might promote generalization within this system.
authors.affiliation: Department of Biology, University of Missouri-St Louis, One University Boulevard, St Louis, MO, 63121-4499, USA.
authors.forename: Maria
authors.initials: M
authors.lastname: Svensson-Coelho
authors.affiliation: Department of Biology, University of Missouri-St Louis, One University Boulevard, St Louis, MO, 63121-4499, USA.
authors.forename: Bette A
authors.initials: BA
authors.lastname: Loiselle
authors.affiliation: Department of Biology, University of Missouri-St Louis, One University Boulevard, St Louis, MO, 63121-4499, USA.
authors.forename: John G
authors.initials: JG
authors.lastname: Blake
authors.affiliation: Department of Biology, University of Missouri-St Louis, One University Boulevard, St Louis, MO, 63121-4499, USA.
authors.forename: Robert E
authors.initials: RE
authors.lastname: Ricklefs
mesh_terms: D000818:Animals; D001717:Birds / Q000469:parasitology*; D004484:Ecuador; D016787:Haemosporida / Q000235:genetics*; D058507:Host Specificity; D006790:Host-Parasite Interactions; D008289:Malaria, Avian / Q000469:parasitology*; D010802:Phylogeny
keywords: avian malaria; community ecology; ecological specialization; species interactions