title: Background level of risk determines how prey categorize predators and non-predators.
abstract: Much of the plasticity that prey exhibit in response to predators is linked to the prey's immediate background level of risk. However, we know almost nothing of how background risk influences how prey learn to categorize predators and non-predators. Learning non-predators probably represents one of the most underappreciated aspects of anti-predator decision-making. Here, we provide larval damselfish (Pomacentrus chrysurus) with a high or low background risk and then try to teach them to recognize a cue as non-threatening through the process of latent inhibition. Prey from the low-risk background that were pre-exposed to the novel odour cues in the absence of negative reinforcement for 3 days, and then provided the opportunity to learn to recognize the odour as threatening, failed to subsequently respond to the odour as a threat. Fish from the high-risk background showed a much different response. These fish did not learn the odour as non-threatening, probably because the cost of falsely learning an odour as non-threatening is higher when the background level of risk is higher. Our work highlights that background level of risk appears to drive plasticity in cognition of prey animals learning to discriminate threats in their environment.
authors.affiliation: Department of Biology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada S7N 5E2 doug.chivers@usask.ca.
authors.forename: Douglas P
authors.initials: DP
authors.lastname: Chivers
authors.affiliation: ARC Centre of Excellence for Coral Reef Studies, and School of Marine and Tropical Biology, James Cook University, Townsville, Queensland 4811, Australia.
authors.forename: Mark I
authors.initials: MI
authors.lastname: McCormick
authors.affiliation: ARC Centre of Excellence for Coral Reef Studies, and School of Marine and Tropical Biology, James Cook University, Townsville, Queensland 4811, Australia.
authors.forename: Matthew D
authors.initials: MD
authors.lastname: Mitchell
authors.affiliation: ARC Centre of Excellence for Coral Reef Studies, and School of Marine and Tropical Biology, James Cook University, Townsville, Queensland 4811, Australia.
authors.forename: Ryan A
authors.initials: RA
authors.lastname: Ramasamy
authors.affiliation: Department of Biomedical Sciences, WCVM, University of Saskatchewan, Saskatoon, Saskatchewan, Canada S7W 5B4.
authors.forename: Maud C O
authors.initials: MC
authors.lastname: Ferrari
mesh_terms: D000818:Animals; D003214:Conditioning, Classical; D057894:Coral Reefs; D003463:Cues; D020387:Food Chain; D007858:Learning; D009812:Odorants; D055696:Olfactory Perception; D010473:Perciformes / Q000502:physiology*; D011235:Predatory Behavior; D011793:Queensland; D012306:Risk
keywords: coral reefs; damselfish; learning; non-predator recognition; predator recognition; risk assessment