title: Hygienic tendencies correlate with low geohelminth infection in free-ranging macaques.
abstract: Parasites are ubiquitous in nature and can be costly to animal fitness, so hosts have evolved behavioural counter-strategies to mitigate infection risk. We investigated feeding-related infection-avoidance strategies in Japanese macaques via field-experimentation and observation. We first examined risk sensitivity during foraging tasks involving faecally contaminated or debris-covered food items, and then investigated individual tendencies to manipulate food items during natural foraging bouts. We concurrently monitored geohelminth infection in all subjects. We ran a principal component analysis on the observational/experimental data to generate a hygienic index across individuals and found that hygienic tendencies towards faeces avoidance and food manipulation correlated negatively with geohelminth infection. Females scored higher in hygienic tendencies than males, which might contribute to the common vertebrate pattern of male-biased infection. The behavioural tendencies observed may reflect a general form of hygiene, providing a mechanism of behavioural immunity against parasites with implications for the evolution and diversification of health maintenance strategies in humans.
authors.affiliation: Primate Research Institute, Kyoto University, Inuyama, Aichi 484-8506, Japan.
authors.forename: Cecile
authors.initials: C
authors.lastname: Sarabian
authors.affiliation: Primate Research Institute, Kyoto University, Inuyama, Aichi 484-8506, Japan Wildlife Research Center, Kyoto University, Sakyo, Kyoto 606-8203, Japan andrew.j.j.macintosh@gmail.com.
authors.forename: Andrew J J
authors.identifier: http://orcid.org/0000-0002-9136-7099
authors.initials: AJ
authors.lastname: MacIntosh
mesh_terms: D000818:Animals; D001070:Appetitive Behavior; D005243:Feces / Q000469:parasitology; D005247:Feeding Behavior; D005260:Female; D006790:Host-Parasite Interactions; D007564:Japan; D008251:Macaca / Q000469:parasitology* / Q000502:physiology*; D008297:Male; D009349:Nematode Infections / Q000469:parasitology*; D009815:Oesophagostomum; D012737:Sex Factors; D014258:Trichuris
keywords: Japanese macaque; antiparasite strategies; health maintenance; hygiene; parasite avoidance behaviour; risk sensitivity