title: Naive tadpoles do not recognize recent invasive predatory fishes as dangerous.
abstract: Invasive alien predators (IAP) are spreading on a global scale-often with devastating ecological effects. One reason for their success may be that prey species fail to recognize them due to a lack of co-evolutionary history. We performed a comprehensive test of this "prey naiveté" hypothesis using a novel approach: we tested whether predator-naive tadpoles of the agile frog (Rana dalmatina) display antipredator behavior upon encountering chemical cues produced by native, invasive (established or recent) or allopatric fishes (four perciforms, four siluriforms, and two cypriniforms). We studied the influence of population origin on predator-detection ability by presenting chemical cues to predator-naive tadpoles that originated from fishless hill-ponds or fish-infested floodplain populations. Before trials, we fed fishes with tadpoles or an alternative food to test whether direct chemical cues from the predator's diet influences the tadpoles' recognition of potential predators. Tadpoles reduced their activity upon exposure to cues from native and long-established invasive perciforms, but not in response to recent invaders, allopatric predators, or to any siluriforms. Also, predators that were previously fed with tadpoles did not universally induce behavioral defensedefenses upon first encounter. Finally, tadpoles originating from isolated hill-ponds exhibited higher baseline activity and responded in weaker fashion than their conspecifics from floodplain populations, which co-exist with predatory fishes. Our results indicate that tadpoles may be vulnerable to invading predatory fishes due to their inability to recognize them as dangerous, though their ability to recognize invasive IAP may evolve rapidly, in fewer than 30 generations.
authors.affiliation: Department of Integrative Biology and Evolution, Konrad Lorenz Institute of Ethology, University of Veterinary Medicine, Vienna, Savoyenstrasse 1A, 1160, Vienna, Austria.|Lendület Evolutionary Ecology Research Group, Plant Protection Institute, Centre for Agricultural Research, Hungarian Academy of Sciences, Herman Ottó út 15, 1022, Budapest, Hungary.
authors.forename: Attila
authors.initials: A
authors.lastname: Hettyey
authors.affiliation: Department of Integrative Biology and Evolution, Konrad Lorenz Institute of Ethology, University of Veterinary Medicine, Vienna, Savoyenstrasse 1A, 1160, Vienna, Austria.
authors.forename: Kerstin E
authors.initials: KE
authors.lastname: Thonhauser
authors.affiliation: Lendület Evolutionary Ecology Research Group, Plant Protection Institute, Centre for Agricultural Research, Hungarian Academy of Sciences, Herman Ottó út 15, 1022, Budapest, Hungary.
authors.forename: Veronika
authors.initials: V
authors.lastname: Bókony
authors.affiliation: Department of Integrative Biology and Evolution, Konrad Lorenz Institute of Ethology, University of Veterinary Medicine, Vienna, Savoyenstrasse 1A, 1160, Vienna, Austria.
authors.forename: Dustin J
authors.initials: DJ
authors.lastname: Penn
authors.affiliation: Department of Integrative Biology and Evolution, Konrad Lorenz Institute of Ethology, University of Veterinary Medicine, Vienna, Savoyenstrasse 1A, 1160, Vienna, Austria.
authors.forename: Herbert
authors.initials: H
authors.lastname: Hoi
authors.affiliation: Department of Integrative Biology and Evolution, Konrad Lorenz Institute of Ethology, University of Veterinary Medicine, Vienna, Savoyenstrasse 1A, 1160, Vienna, Austria.|Department of Biology, University of Padova, Via U. Bassi 58B, 35121, Padova, Italy.
authors.forename: Matteo
authors.initials: M
authors.lastname: Griggio
mesh_terms: D000818:Animals; D004924:Escape Reaction / Q000502:physiology*; D005399:Fishes / Q000502:physiology*; D007814:Larva / Q000502:physiology; D011235:Predatory Behavior / Q000502:physiology*; D011898:Ranidae / Q000502:physiology*
keywords: antipredator behavior; history of coexistence; inducible defense; invasive species; predator recognition