Components of predatory behaviour underlying density-dependent prey-size selection by Notiophilus biguttatus F....

Area of Science:

• Ecology
• Zoology
• Behavioral Ecology

Background:

• Predator-prey dynamics are crucial in ecological systems.
• Optimal foraging theory predicts how predators maximize energy intake.
• Prey size influences predator attack success and diet composition.

Purpose of the Study:

• To investigate prey-size selection in the carabid beetle Notiophilus biguttatus.
• To model prey-size selection based on attack readiness and success ratio.
• To test the model's predictions regarding prey density and diet composition.

Main Methods:

• Studied Notiophilus biguttatus feeding on two size classes of Orchesella cincta (Collembola).
• Measured attack readiness and success ratio for different prey sizes.
• Developed a prey-size selection model incorporating these parameters.
• Experimentally tested model predictions in artificial and semi-natural environments.

Main Results:

• Smaller prey elicited higher attack readiness and success rates.
• The model predicted increased large prey consumption at lower total prey densities.
• Experimental results qualitatively supported the model's prediction.
• Quantitative results deviated due to higher beetle attack readiness in semi-natural settings.

Conclusions:

• Prey size and density are key factors in carabid beetle foraging behavior.
• Environmental context significantly influences predator attack readiness.
• Findings contribute to understanding optimal foraging theory and ecological interactions.