Host range and community structure of avian nest parasites in the genus Philornis (Diptera: Muscidae) on the island of Trinidad. Issue 17 (15th August 2015)

• Record Type: Journal Article
• Authors: Bulgarella, Mariana; Heimpel, George E.
• Is Part Of: Ecology and evolution. Volume 5:Issue 17(2015:Sep.)
• Page Start: 3695
• Page End: 3703
• Publication Date: 2015-08-15
• Subjects: Ecology -- Periodicals; Evolution -- Periodicals; 577.05
• DOI: 10.1002/ece3.1621
• Languages: English
• ISSNs: 2045-7758

Abstract

<abstract abstract-type="main" id="ece31621-abs-0001"> <title>Abstract</title> <p>Parasite host range can be influenced by physiological, behavioral, and ecological factors. Combining data sets on host–parasite associations with phylogenetic information of the hosts and the parasites involved can generate evolutionary hypotheses about the selective forces shaping host range. Here, we analyzed associations between the nest‐parasitic flies in the genus <italic>Philornis</italic> and their host birds on Trinidad. Four of ten <italic>Philornis</italic> species were only reared from one species of bird. Of the parasite species with more than one host bird species, <italic>P. falsificus</italic> was the least specific and <italic>P. deceptivus</italic> the most specific attacking only Passeriformes. <italic>Philornis</italic> flies in Trinidad thus include both specialists and generalists<italic>, </italic> with varying degrees of specificity within the generalists. We used three quantities to more formally compare the host range of <italic>Philornis</italic> flies: the number of bird species attacked by each species of <italic>Philornis</italic>, a phylogenetically informed host specificity index (Poulin and Mouillot's <italic>S</italic><sub>TD</sub>), and a branch length‐based <italic>S</italic><sub>TD</sub>. We then assessed the phylogenetic signal of these measures of host range for 29 bird species. None of these measures showed significant phylogenetic signal, suggesting that clades of <italic>Philornis</italic> did not differ significantly in their ability to exploit hosts. We also calculated two quantities of parasite species load for the birds – the parasite species richness, and a variant of the <italic>S</italic><sub>TD</sub> index based on nodes rather than on taxonomic levels – and assessed the signal of these measures on the bird phylogeny. We did not find significant phylogenetic signal for the parasite species load or the node‐based <italic>S</italic><sub>TD</sub> index. Finally, we calculated the parasite associations for all bird pairs using the Jaccard index and regressed these similarity values against the number of nodes in the phylogeny separating bird pairs. This analysis showed that <italic>Philornis</italic> on Trinidad tend to feed on closely related bird species more often than expected by chance.</p> </abstract>