title: Disrupted learning: habitat degradation impairs crucial antipredator responses in naive prey.
abstract: Habitat degradation is a global problem and one of the main causes of biodiversity loss. Though widespread, the mechanisms that underlie faunal changes are poorly understood. In tropical marine systems, corals play a crucial role in forming habitat, but coral cover on many reefs is declining sharply. Coral degradation affects the olfactory cues that provide reliable information on the presence and intensity of threat. Here, we show for the first time that the ability of a habitat generalist to learn predators using an efficient and widespread method of predator learning is compromised in degraded coral habitats. Results indicate that chemical alarm cues are no longer indicative of a local threat for the habitat generalist (the damselfish, Pomacentrus amboinensis), and these cues can no longer be used to learn the identity of novel predators in degraded habitats. By contrast, a rubble specialist and congeneric (Pomacentrus coelestis) responded to olfactory threat cues regardless of background environment and could learn the identity of a novel predator using chemical alarm cues. Understanding how some species can cope with or acclimate to the detrimental impacts of habitat degradation on risk assessment abilities will be crucial to defining the scope of resilience in threatened communities.
authors.affiliation: ARC Centre of Excellence for Coral Reef Studies and College of Marine and Environmental Sciences, James Cook University, Townsville, Queensland, Australia mark.mccormick@jcu.edu.au.
authors.forename: Mark I
authors.identifier: 0000-0001-9289-1645
authors.initials: MI
authors.lastname: McCormick
authors.affiliation: ARC Centre of Excellence for Coral Reef Studies and College of Marine and Environmental Sciences, James Cook University, Townsville, Queensland, Australia Department of Ecology and Genetics, Limnology, Uppsala University, Uppsala, Sweden.
authors.forename: Oona M
authors.identifier: 0000-0003-2471-1141
authors.initials: OM
authors.lastname: Lönnstedt
mesh_terms: D000818:Animals; D037421:Anthozoa; D001362:Avoidance Learning; D001522:Behavior, Animal; D057894:Coral Reefs; D003463:Cues; D017753:Ecosystem; D007858:Learning / Q000502:physiology; D010473:Perciformes / Q000502:physiology*; D011235:Predatory Behavior; D012903:Smell
keywords: chemical alarm cue; coral reef fishes; habitat degradation; predator–prey; risk assessment; threat learning