Top-Down and Bottom-Up Processes Jointly Explain Mesopredator Movement and Foraging Ecology

Area of Science:

• Ecology
• Wildlife Conservation
• Behavioral Ecology

Background:

• Predator-prey dynamics significantly influence animal behavior and distribution.
• Understanding risk-reward tradeoffs is crucial for managing species, especially in changing environments.

Purpose of the Study:

• To investigate how polar bear predation risk and fish prey availability affect ringed seal habitat selection, movement, and foraging.
• To assess the combined impact of top-down and bottom-up factors on mesopredator behavior.

Main Methods:

• Analysis of over 70,000 dives and 10,000 locations from 26 ringed seals.
• Modeling of polar bear habitat selection (top-down) and fish diversity (bottom-up).
• Comparison of seal habitat use with and without considering predation risk.

Main Results:

• Polar bear presence was found to restrict ringed seal movement and reduce foraging time.
• Seals exhibited increased presence and dive duration in high-risk areas when prey diversity was high.
• Habitat models that excluded polar bear influence overestimated ringed seal core space use.

Conclusions:

• Ringed seals dynamically adjust their behavior to balance the risks of predation with the need for foraging.
• Predation risk from polar bears significantly shapes ringed seal ecology, impacting their movement and foraging success.
• Accurate ecological models must incorporate multiple predator-prey interactions for effective conservation and management.