Predator-induced shifts in oviposition and colonization of aquatic habitats: A meta-analysis and conceptual model of consequences for regional recruitment

Predation is an important factor shaping patterns of abundance in aquatic communities. Although studies have historically focused on the consumptive effects of predators in shaping these patterns, a growing body of research shows that the non-consumptive effects of predators may be equally important. For example, many taxa can detect and avoid colonizing (e.g., via oviposition) habitats occupied by predators. This non-consumptive effect of aquatic predators on prey habitat selection may play an important role in determining species distribution and abundance in aquatic communities.  Here we present a meta-analysis of experimental studies of risk-sensitive oviposition and colonization of aquatic habitats.  Predator-sensitive habitat selection is a wide spread phenomenon among taxa with complex life histories that colonize aquatic habitats and the magnitude of these effects is typically large. We develop a conceptual model examining the independent and combined effects of predator-induced habitat selection and subsequent post-colonization predator effects on regional recruitment. We use this framework to gain insight into how local within-patch (e.g., local carry capacity) and landscape, among-patch characteristics (e.g., proportion of predator occupied patches, the costs of movement among patches) determine the relative importance of predator effects on regional recruitment. Model results suggest that predator effects on habitat selection per se can have important consequences for regional recruitment independent of their consumptive effects.  The degree to which predator avoidance is able to ameliorate the consumptive effects of predators depends upon both local and landscape level conditions.