Predator olfactory cues generate a foraging-predation trade-off through prey apprehension

Area of Science:

• Behavioral Ecology
• Predator-Prey Dynamics
• Animal Behavior

Background:

• Animals balance foraging with predation risk, often reducing activity to avoid predators.
• This trade-off can lead to decreased foraging success.
• Predation risk may also impose indirect costs through heightened prey apprehension.

Purpose of the Study:

• To test the 'apprehension cost' hypothesis in predator-prey interactions.
• To investigate if damselflies experience reduced foraging efficiency due to apprehension.
• To differentiate between direct and indirect costs of anti-predator responses.

Main Methods:

• Exposing damselflies to olfactory cues from fish predators and from conspecifics exposed to predators.
• Observing damselfly activity levels and foraging success (prey capture rates).
• Comparing feeding efficiency under different predator cue conditions.

Main Results:

• Damselflies exhibited reduced activity in response to predator cues, a known anti-predator behavior.
• Damselflies missed a significantly greater proportion of prey when exposed to predator cues.
• This reduced feeding efficiency occurred alongside, and in addition to, reduced activity.

Conclusions:

• Predation risk incurs indirect costs on prey through apprehension and multitasking.
• Apprehension leads to decreased foraging efficiency, independent of reduced movement.
• Understanding these indirect costs is crucial for a complete picture of anti-predator responses.