title: Lesser snow goose helminths show recurring and positive parasite infection-diversity relations.
abstract: The patterns and mechanisms by which biological diversity is associated with parasite infection risk are important to study because of their potential implications for wildlife population's conservation and management. Almost all research in this area has focused on host species diversity and has neglected parasite diversity, despite evidence that parasites are important drivers of community structure and ecosystem processes. Here, we assessed whether presence or abundance of each of nine helminth species parasitizing lesser snow geese (Chen caerulescens) was associated with indices of parasite diversity (i.e. species richness and Shannon's Diversity Index). We found repeated instances of focal parasite presence and abundance having significant positive co-variation with diversity measures of other parasites. These results occurred both within individual samples and for combinations of all samples. Whereas host condition and parasite facilitation could be drivers of the patterns we observed, other host- or parasite-level effects, such as age or sex class of host or taxon of parasite, were discounted as explanatory variables. Our findings of recurring and positive associations between focal parasite abundance and diversity underscore the importance of moving beyond pairwise species interactions and contexts, and of including the oft-neglected parasite species diversity in infection-diversity studies.
authors.affiliation: Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, ON, K1S-5B6, Canada.
authors.forename: Felipe
authors.initials: F
authors.lastname: Dargent
authors.affiliation: Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, ON, K1S-5B6, Canada.
authors.forename: André
authors.initials: A
authors.lastname: Morrill
authors.affiliation: Environment Canada, Prairie & Northern Wildlife Research Centre, 115 Perimeter Road, Saskatoon, SK, S7N 0X4, Canada; Department of Biology, University of Saskatchewan, 112 Science Place, Saskatoon, SK, S7N 5E2, Canada.
authors.forename: Ray T
authors.initials: RT
authors.lastname: Alisauskas
authors.affiliation: Department of Biology, Concordia University, 7141 Sherbrooke St. W., Montreal, QC, H4B 1R6, Canada.
authors.forename: J Daniel
authors.initials: JD
authors.lastname: McLaughlin
authors.affiliation: Department of Biology, Acadia University, 33 Westwood Avenue, Wolfville, NS, B4P 2R6, Canada.
authors.forename: Dave
authors.initials: D
authors.lastname: Shutler
authors.affiliation: Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, ON, K1S-5B6, Canada.
authors.forename: Mark R
authors.initials: MR
authors.lastname: Forbes
keywords: Biodiversity; Chen caerulescens; Co-infection; Dilution; Facilitation; North America; Parasite aggregation