title: Parasite treatment affects maternal investment in sons.
abstract: Parasitism can be a major constraint on host condition and an important selective force. Theoretical and empirical evidence shows that maternal condition affects relative investment in sons and daughters; however, the effect of parasitism on sex ratio in vertebrates is seldom considered. We demonstrate experimentally that parasitism constrains the ability of mothers to rear sons in a long-lived seabird, the European shag Phalacrocorax aristotelis. The effect contributes to the decline in offspring survival as the breeding season progresses and hence has important population-level consequences for this, and potentially other, seasonal breeders.
authors.affiliation: Institute of Evolutionary Biology, University of Edinburgh, Edinburgh EH9 3JT, UK. tomreed@u.washington.edu
authors.forename: T E
authors.initials: TE
authors.lastname: Reed
authors.forename: F
authors.initials: F
authors.lastname: Daunt
authors.forename: M E
authors.initials: ME
authors.lastname: Hall
authors.forename: R A
authors.initials: RA
authors.lastname: Phillips
authors.forename: S
authors.initials: S
authors.lastname: Wanless
authors.forename: E J A
authors.initials: EJ
authors.lastname: Cunningham
mesh_terms: D000818:Animals; D000969:Antinematodal Agents / Q000627:therapeutic use; D017191:Ascaridida Infections / Q000188:drug therapy / Q000503:physiopathology / Q000662:veterinary*; D001199:Ascaridoidea; D001715:Bird Diseases / Q000188:drug therapy / Q000503:physiopathology*; D001717:Birds / Q000469:parasitology* / Q000502:physiology*; D005247:Feeding Behavior; D005260:Female; D007559:Ivermectin / Q000627:therapeutic use*; D008297:Male; D009425:Nesting Behavior; D012098:Reproduction; D012727:Sex Characteristics; D012744:Sex Ratio; D015996:Survival Rate
chemical_list: D000969:Antinematodal Agents; D007559:Ivermectin