Our lab has a longstanding interest in predator-prey relationships, as well as related interactions between parasites and hosts, and herbivores and plants. We address questions in predator-prey ecology either using experimental studies involving tadpoles and their predators, or through field studies with a variety of mammal, bird and reptile species.
Phenotypic plasticity
Prey have the well-known ability to detect predation risk via signals transmitted by the predator. In aquatic systems, such information is released through chemical cues, of which surprisingly little is known. We have identified the unique chemical structure of some predator chemical cues, and have quantified how they affect behaviour and morphology of tadpole prey. We are in the process of examining prey fitness tradeoffs activated by these cues, whether cues originate exclusively from predators or prey rather than being released as by-products of prey digestion, and how prey-mediated cues may help increase their inclusive fitness. Of particular interest are questions related to how prey can balance behavioural and morphological adaptations to predation risk by means of these cues, and how the proper balance between behaviour and morphology may affect responses to other challenges faced by prey, such as malnutrition or disease.
Prey have the well-known ability to detect predation risk via signals transmitted by the predator. In aquatic systems, such information is released through chemical cues, of which surprisingly little is known. We have identified the unique chemical structure of some predator chemical cues, and have quantified how they affect behaviour and morphology of tadpole prey. We are in the process of examining prey fitness tradeoffs activated by these cues, whether cues originate exclusively from predators or prey rather than being released as by-products of prey digestion, and how prey-mediated cues may help increase their inclusive fitness. Of particular interest are questions related to how prey can balance behavioural and morphological adaptations to predation risk by means of these cues, and how the proper balance between behaviour and morphology may affect responses to other challenges faced by prey, such as malnutrition or disease.
Predation risk avoidance
Individual prey exhibit behaviours that might go unnoticed except for the fact that they contribute to increased vulnerability to predation, either directly or through interactions with other factors. Central to this area of research is the starvation-predation risk tradeoff hypothesis, which addresses how prey should balance ongoing and conflicting demands of food acquisition vs. predation avoidance. We are examining how prey assess the various risks they are faced with and how they adjust their behaviour to conform to such risks. We are especially interested in how prey decisions related to the starvation-predation risk gradient can be altered dramatically by varying the spatial or temporal distribution of risks and rewards in the environment.
Individual prey exhibit behaviours that might go unnoticed except for the fact that they contribute to increased vulnerability to predation, either directly or through interactions with other factors. Central to this area of research is the starvation-predation risk tradeoff hypothesis, which addresses how prey should balance ongoing and conflicting demands of food acquisition vs. predation avoidance. We are examining how prey assess the various risks they are faced with and how they adjust their behaviour to conform to such risks. We are especially interested in how prey decisions related to the starvation-predation risk gradient can be altered dramatically by varying the spatial or temporal distribution of risks and rewards in the environment.
Prey selection and mortality patterns
Predators can have profound effects on prey survival, and prey that are killed by predators are not exclusively sick and lame individuals as was formerly thought. A variety of subtle conditions and behaviours predispose individual prey to predation risk, but prey selection patterns tend to be quite variable among different populations or time periods, making it difficult to develop general rules of thumb about who will get killed. In addition, prey selection patterns can be strongly influenced by the hunting tactics employed by the predator involved in the encounter, leading to the logical question of how prey selection and risk are shaped by prey attributes vs. predator hunting tactics. We are also interested in the impacts of selective prey mortality on prey populations; this work usually involves monitoring prey survival and cause-specific mortality, and making population-level inferences about likely outcomes of prey selection. Inevitably, this research takes us down the path of assessing subtle prey risk determinants, predator functional responses, prey refuge use patterns, and predator hunting strategies.
Predators can have profound effects on prey survival, and prey that are killed by predators are not exclusively sick and lame individuals as was formerly thought. A variety of subtle conditions and behaviours predispose individual prey to predation risk, but prey selection patterns tend to be quite variable among different populations or time periods, making it difficult to develop general rules of thumb about who will get killed. In addition, prey selection patterns can be strongly influenced by the hunting tactics employed by the predator involved in the encounter, leading to the logical question of how prey selection and risk are shaped by prey attributes vs. predator hunting tactics. We are also interested in the impacts of selective prey mortality on prey populations; this work usually involves monitoring prey survival and cause-specific mortality, and making population-level inferences about likely outcomes of prey selection. Inevitably, this research takes us down the path of assessing subtle prey risk determinants, predator functional responses, prey refuge use patterns, and predator hunting strategies.