Meeting Abstract
Encounters between predators and prey lead to capture and consumption of the prey or a nonlethal avoidance response when the prey changes its behavior to evade the threat. Either outcome is costly for prey. However, not all predators represent equal threats, especially when predators are gape limited. Prey solve this problem by obtaining information about a predator from a variety of sensory cues that they use to assess risk, to avoid responding to nonthreatening predators. Chemical cues in the form of predator odors provide information about the predator’s species identity, health, satiation state, and previous dietary components. Odors also indicate the size of the predator, which could inform prey if a predator poses a threat relative to their own body size . Rusty crayfish (Faxonius rusticus) were exposed to odor cues produced by two gape limited predatory fish, Largemouth Bass (Micropterus salmoides) and Rainbow Trout (Oncorhynchus mykiss) across a gradient of relative size relationships. Crayfish consumed more macrophytes when exposed to odors from bass that were large relative to the crayfish. There was no change in macrophyte consumption by crayfish exposed to trout odors along the same relative size gradient. Foraging effort and shelter use behaviors of the crayfish were also impacted by odors from predators that were large relative to the size of the prey. Thus, crayfish can extract size information from predator odor cues and use this information to determine if the predator represents a threat relative to their own body size. However, the responses are also species specific, which further supports the hypothesis that prey assess risks relative to the threat posed by individual predators.
