| Affiliation: | 1. School of Biology and Environmental Science, Faculty of Science, Queensland University of Technology, Brisbane, Queensland, Australia;2. Centre for Compassionate Conservation, TD School, University of Technology Sydney, Ultimo, New South Wales, Australia;3. Department of Zoology, Faculty of Sciences, University of Granada, Granada, Spain;4. Department of Entomology and Nematology, University of California Davis, Berkeley, California, USA;5. Department of Biological Sciences, Macquarie University, North Ryde, New South Wales, Australia;6. Hawkesbury Institute for the Environment, Western Sydney University, Penrith, New South Wales, Australia;7. School of Life Sciences, University of Sussex, Brighton, UK;8. Center for Biodiversity Dynamics in a Changing World (BIOCHANGE), Department of Biology, Aarhus University, Aarhus, Denmark Section for Ecoinformatics and Biodiversity, Department of Biology, Aarhus University, Aarhus, Denmark |
| Abstract: | The prey naivety hypothesis posits that prey are vulnerable to introduced predators because many generations in slow gradual coevolution are needed for appropriate avoidance responses to develop. It predicts that prey will be more responsive to native than introduced predators and less responsive to introduced predators that differ substantially from native predators and from those newly established. To test these predictions, we conducted a global meta-analysis of studies that measured the wariness responses of small mammals to the scent of sympatric mammalian mesopredators. We identified 26 studies that met our selection criteria. These studies comprised 134 experiments reporting on the responses of 36 small mammal species to the scent of six introduced mesopredators and 12 native mesopredators. For each introduced mesopredator, we measured their phylogenetic and functional distance to local native mesopredators and the number of years sympatric with their prey. We used predator and prey body mass as a measure of predation risk. Globally, small mammals were similarly wary of the scent of native and introduced mesopredators; phylogenetic and functional distance between introduced mesopredators and closest native mesopredators had no effect on wariness; and wariness was unrelated to the number of prey generations, or years, since first contact with introduced mesopredators. Small mammal wariness was associated with predator-prey body mass ratio, regardless of the nativity. The one thing animals do not seem to recognize is whether their predators are native. |
