Prey susceptibilities, prey utilization and variable attack efficiencies of Ural owls

Area of Science:

• Behavioral Ecology
• Predator-Prey Dynamics

Background:

• Optimal foraging theory predicts predators maximize energy intake.
• Understanding prey utilization is key to predator-prey dynamics.

Purpose of the Study:

• Investigate factors influencing prey utilization in Ural owls (Strix uralensis).
• Examine prey selection and capture success in relation to foraging behavior.

Main Methods:

• Conducted experiments with Ural owls and three mouse species (Microtus montebelli, Apodemus speciosus, A. argenteus) in a flight cage.
• Recorded owl attacks and capture success rates under varying conditions.

Main Results:

• Owl attacks did not differ from random predictions; M. montebelli was utilized more than Apodemus species.
• Prey utilization was primarily linked to prey susceptibility, not owl selection.
• Capture success varied between experiments, increasing under poor food conditions, contradicting constant capture probability assumptions.

Conclusions:

• Prey utilization in Ural owls is influenced by prey susceptibility and predator's capture success flexibility.
• Observed foraging behavior challenges core assumptions of optimal foraging theory regarding constant capture probabilities.
• Owl's ability to adjust capture success, rather than prey selection, is crucial for energy gain.