Mortality, perception, and scale: Understanding how predation shapes space use in a wild prey population

Area of Science:

• Ecology
• Behavioral Ecology
• Wildlife Management

Background:

• Assessing prey behavioral responses to predation risk is challenging due to direct mortality.
• The scale of assessment significantly impacts understanding how predation risk influences prey behavior.

Purpose of the Study:

• To investigate how spatial and temporal variations in recreational hunting (predation risk) affect the space use of wild Ring-necked Pheasants (Phasianus colchicus).
• To determine the influence of different spatial scales (home range vs. nightly resting locations) on observed behavioral responses.

Main Methods:

• Radio-marked Ring-necked Pheasants to monitor space use at seasonal home range and nightly resting location scales.
• Monitored pheasant space use before and during the hunting season to account for temporal risk variation.
• Compared space use patterns under varying levels of perceived and actual predation risk.

Main Results:

• Pheasants expanded and shifted home ranges in response to predation risk, even when invulnerable.
• Home ranges exhibited plasticity, expanding and contracting with fluctuating risk levels.
• No change in nightly resting locations was observed.
• Direct depredation (mortality) obscured the population-level behavioral responses to perceived risk.

Conclusions:

• Predation risk significantly influences prey space use, particularly home range dynamics.
• The scale of ecological assessment is critical; failure to use appropriate scales can mask important behavioral effects due to differential mortality.
• Understanding prey behavior requires multi-scale analysis considering both perceived risk and direct mortality.