The fitness trade-offs of predation: when to scavenge and when to steal
AbstractThe costs of foraging can be high while also carrying significant risks.
To mitigate these risks, many predators supplement active hunting with
scavenging and kleptoparasitism, in some cases specializing in these
alternative modes of predation. However, the factors that drive
differential utilization of these strategies are not well understood.
Here we use an energetics approach to investigate the fitness advantages
of hunting, scavenging, and kleptoparasitism as a function of predator,
prey, and competitor body sizes for terrestrial mammalian carnivores.
Our results reveal that predator strategies become more diverse with
declining body condition, while the deployment of scavenging and
kleptoparasitism is strongly constrained by the ratio of predator to
prey body size. Our model accurately predicts a behavioral transition
away from hunting towards alternative modes of predation with increasing
prey size for predators spanning an order of magnitude in body size,
closely matching observational data across a range of species.