title: Androgens predict parasitism in female meerkats: a new perspective on a classic trade-off.
abstract: The immunocompetence handicap hypothesis posits that androgens in males can be a 'double-edged sword', actively promoting reproductive success, while also negatively impacting health. Because there can be both substantial androgen concentrations in females and significant androgenic variation among them, particularly in species portraying female social dominance over males or intense female-female competition, androgens might also play a role in mediating female health and fitness. We examined this hypothesis in the meerkat (Suricata suricatta), a cooperatively breeding, social carnivoran characterized by aggressively mediated female social dominance and extreme rank-related reproductive skew. Dominant females also have greater androgen concentrations and harbour greater parasite loads than their subordinate counterparts, but the relationship between concurrent androgen concentrations and parasite burdens is unknown. We found that a female's faecal androgen concentrations reliably predicted her concurrent state of endoparasitism irrespective of her social status: parasite species richness and infection by Spirurida nematodes, Oxynema suricattae, Pseudandrya suricattae and coccidia were greater with greater androgen concentrations. Based on gastrointestinal parasite burdens, females appear to experience the same trade-off in the costs and benefits of raised androgens as do the males of many species. This trade-off presumably represents a health cost of sexual selection operating in females.
authors.affiliation: University Program in Ecology, Duke University, Durham NC 27708, USA kendra.smyth@duke.edu.|Department of Evolutionary Anthropology, Duke University, Durham NC 27708, USA.|Kalahari Research Trust, Kuruman River Reserve, Northern Cape 8467, South Africa.
authors.forename: Kendra N
authors.identifier: 0000-0002-7563-3406
authors.initials: KN
authors.lastname: Smyth
authors.affiliation: University Program in Ecology, Duke University, Durham NC 27708, USA.|Department of Evolutionary Anthropology, Duke University, Durham NC 27708, USA.|Kalahari Research Trust, Kuruman River Reserve, Northern Cape 8467, South Africa.
authors.forename: Lydia K
authors.initials: LK
authors.lastname: Greene
authors.affiliation: Kalahari Research Trust, Kuruman River Reserve, Northern Cape 8467, South Africa.|Department of Zoology, University of Cambridge, Cambridge CB2 3EJ, UK.|Mammal Research Institute, University of Pretoria, Pretoria 0028, South Africa.
authors.forename: Tim
authors.initials: T
authors.lastname: Clutton-Brock
authors.affiliation: University Program in Ecology, Duke University, Durham NC 27708, USA.|Department of Evolutionary Anthropology, Duke University, Durham NC 27708, USA.|Department of Biology, Duke University, Durham NC 27708, USA.|Kalahari Research Trust, Kuruman River Reserve, Northern Cape 8467, South Africa.
authors.forename: Christine M
authors.initials: CM
authors.lastname: Drea
mesh_terms: D000728:Androgens / Q000378:metabolism*; D000818:Animals; D002589:Cestoda / Q000302:isolation & purification; D003044:Coccidia / Q000302:isolation & purification; D005243:Feces / Q000737:chemistry* / Q000469:parasitology; D005260:Female; D008988:Herpestidae / Q000469:parasitology* / Q000502:physiology*; D009348:Nematoda / Q000302:isolation & purification; D012930:Social Dominance
chemical_list: D000728:Androgens
keywords: ecoimmunology; helminth; mammal; masculinization; testosterone