title: The effects of predator odors in mammalian prey species: a review of field and laboratory studies.
abstract: Prey species show specific adaptations that allow recognition, avoidance and defense against predators. For many mammalian species this includes sensitivity towards predator-derived odors. The typical sources of such odors include predator skin and fur, urine, feces and anal gland secretions. Avoidance of predator odors has been observed in many mammalian prey species including rats, mice, voles, deer, rabbits, gophers, hedgehogs, possums and sheep. Field and laboratory studies show that predator odors have distinctive behavioral effects which include (1) inhibition of activity, (2) suppression of non-defensive behaviors such as foraging, feeding and grooming, and (3) shifts to habitats or secure locations where such odors are not present. The repellent effect of predator odors in the field may sometimes be of practical use in the protection of crops and natural resources, although not all attempts at this have been successful. The failure of some studies to obtain repellent effects with predator odors may relate to (1) mismatches between the predator odors and prey species employed, (2) strain and individual differences in sensitivity to predator odors, and (3) the use of predator odors that have low efficacy. In this regard, a small number of recent studies have suggested that skin and fur-derived predator odors may have a more profound lasting effect on prey species than those derived from urine or feces. Predator odors can have powerful effects on the endocrine system including a suppression of testosterone and increased levels of stress hormones such as corticosterone and ACTH. Inhibitory effects of predator odors on reproductive behavior have been demonstrated, and these are particularly prevalent in female rodent species. Pregnant female rodents exposed to predator odors may give birth to smaller litters while exposure to predator odors during early life can hinder normal development. Recent research is starting to uncover the neural circuitry activated by predator odors, leading to hypotheses about how such activation leads to observable effects on reproduction, foraging and feeding.
authors.affiliation: Tierphysiologie, Zoologisches Institut, Universität Tübingen, Auf der Morgenstelle 28, D-72076 Tübingen, Germany. raimund.apfelbach@uni-tuebingen.de
authors.forename: Raimund
authors.initials: R
authors.lastname: Apfelbach
authors.forename: Caroline D
authors.initials: CD
authors.lastname: Blanchard
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Blanchard
authors.forename: R Andrew
authors.initials: RA
authors.lastname: Hayes
authors.forename: Iain S
authors.initials: IS
authors.lastname: McGregor
mesh_terms: D000818:Animals; D001362:Avoidance Learning / Q000502:physiology*; D001522:Behavior, Animal; D004703:Endocrine System / Q000502:physiology; D020387:Food Chain; D006801:Humans; D008297:Male; D009812:Odorants; D010675:Pheromones / Q000494:pharmacology; D011235:Predatory Behavior / Q000502:physiology*; D012737:Sex Factors; D012903:Smell
chemical_list: D010675:Pheromones