title: Parasite and predator risk assessment: nuanced use of olfactory cues.
abstract: Foraging herbivores face twin threats of predation and parasite infection, but the risk of predation has received much more attention. We evaluated, experimentally, the role of olfactory cues in predator and parasite risk assessment on the foraging behaviour of a population of marked, free-ranging, red-necked wallabies (Macropus rufogriseus). The wallabies adjusted their behaviour according to these olfactory cues. They foraged less, were more vigilant and spent less time at feeders placed in the vicinity of faeces from dogs that had consumed wallaby or kangaroo meat compared with that of dogs feeding on sheep, rabbit or possum meat. Wallabies also showed a species-specific faecal aversion by consuming less food from feeders contaminated with wallaby faeces compared with sympatric kangaroo faeces, whose gastrointestinal parasite fauna differs from that of the wallabies. Combining both parasite and predation cues in a single field experiment revealed that these risks had an additive effect, rather than the wallabies compromising their response to one risk at the expense of the other.
authors.affiliation: School of BioScience, The University of Melbourne, Victoria 3010, Australia john1608@tpg.com.au.
authors.forename: John G
authors.initials: JG
authors.lastname: Sharp
authors.affiliation: School of BioScience, The University of Melbourne, Victoria 3010, Australia.
authors.forename: Sarah
authors.initials: S
authors.lastname: Garnick
authors.affiliation: School of BioScience, The University of Melbourne, Victoria 3010, Australia.
authors.forename: Mark A
authors.initials: MA
authors.lastname: Elgar
authors.affiliation: School of BioScience, The University of Melbourne, Victoria 3010, Australia.
authors.forename: Graeme
authors.initials: G
authors.lastname: Coulson
mesh_terms: D000818:Animals; D001070:Appetitive Behavior / Q000502:physiology*; D003463:Cues; D004285:Dogs / Q000502:physiology*; D005243:Feces; D005247:Feeding Behavior / Q000502:physiology*; D007614:Macropodidae / Q000469:parasitology / Q000502:physiology*; D009812:Odorants; D011235:Predatory Behavior / Q000502:physiology; D011817:Rabbits; D012756:Sheep; D012903:Smell / Q000502:physiology*; D048330:Trichosurus; D014739:Victoria
keywords: anti-predator behaviour; faecal aversion; foraging behaviour; macropodid marsupials; parasite avoidance; predator detection