title: Phylogenetic relatedness and ecological interactions determine antipredator behavior.
abstract: Interspecific recognition of alarm cues among guild members through "eavesdropping" may allow prey to fine-tune antipredator responses. This process may be linked to taxonomic relatedness but might also be influenced by local adaptation to recognize alarm cues from sympatric species. We tested this hypothesis using antipredator responses of a freshwater gastropod Lymnaea stagnalis (L.) to alarm cues from damaged conspecific and 10 heterospecific gastropod species. As predicted, the magnitude of antipredator response decreased significantly with increasing phylogenetic distance, but increased when species were naturally sympatric (defined as species cohabiting in the same water body) with the source population of L. stagnalis. The responses to sympatric species were higher overall, and the relationship between genetic distance and alarm cue response was stronger when tested with sympatric species. This is the first study to demonstrate that population sympatry influences innate antipredator responses to alarm cues from intraguild members and suggests that responses based on phylogenetic relationships can be modified through local adaptation. Such adaptation to heterospecific alarm cues suggests that species could be at a disadvantage when they encounter novel intraguild members resulting from species invasion or range expansion due to a reduction in the presence of reliable information about predation risk.
authors.affiliation: Marine Biology and Ecology Research Centre, School of Biological Sciences, University of Plymouth, Plymouth PL4 8AA, United Kingdom. sdalesman@plymouth.ac.uk
authors.forename: Sarah
authors.initials: S
authors.lastname: Dalesman
authors.forename: Simon D
authors.initials: SD
authors.lastname: Rundle
authors.forename: David T
authors.initials: DT
authors.lastname: Bilton
authors.forename: Peter A
authors.initials: PA
authors.lastname: Cotton
mesh_terms: D000222:Adaptation, Physiological; D000819:Animal Communication; D000818:Animals; D005075:Biological Evolution; D003463:Cues; D017753:Ecosystem; D049851:Gastropoda / Q000145:classification / Q000502:physiology*; D008195:Lymnaea / Q000145:classification / Q000502:physiology*; D010802:Phylogeny; D011157:Population Dynamics; D011235:Predatory Behavior / Q000502:physiology*; D013045:Species Specificity