title: The interactive effects of competition and predation risk on dispersal in an insect.
abstract: Dispersal dynamics have significant consequences for ecological and evolutionary processes. Previous work has demonstrated that dispersal can be context-dependent. However, factors affecting dispersal are typically considered in isolation, despite the probability that individuals make dispersal decisions in response to multiple, possibly interacting factors. We examined whether two ecological factors, predation risk and intraspecific competition, have interactive effects on dispersal dynamics. We performed a factorial experiment in mesocosms using backswimmers (Notonecta undulata), flight-capable, semi-aquatic insects. Emigration rates increased with density, and increased with predation risk at intermediate densities; however, predation had minimal effects on emigration at high and low densities. Our results indicate that factorial experiments may be required to understand dispersal dynamics under realistic ecological conditions.
authors.affiliation: Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks Street, Toronto, Ontario, Canada M5S3B2 celina.baines@mail.utoronto.ca.
authors.forename: Celina B
authors.initials: CB
authors.lastname: Baines
authors.affiliation: Department of Biology, University of Toronto Mississauga, 3359 Mississauga Road North, Mississauga, Ontario, Canada L5L1C6.
authors.forename: Shannon J
authors.initials: SJ
authors.lastname: McCauley
authors.affiliation: Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks Street, Toronto, Ontario, Canada M5S3B2.
authors.forename: Locke
authors.initials: L
authors.lastname: Rowe
mesh_terms: D063147:Animal Distribution / Q000502:physiology*; D000818:Animals; D001522:Behavior, Animal / Q000502:physiology; D020062:Heteroptera / Q000502:physiology*; D011156:Population Density; D011157:Population Dynamics; D011235:Predatory Behavior / Q000502:physiology; D012306:Risk; D012919:Social Behavior
keywords: Notonecta; context-dependent dispersal; dispersal; predator–prey