Invasion Dynamics in an Intraguild Predation System with Predator-Induced Defense

Area of Science:

• Ecology
• Theoretical Ecology
• Mathematical Biology

Background:

• Intraguild predation systems, where predators consume prey that also competes for resources, are common in food webs.
• Classical models (Holling type II) fail to predict predator coexistence in resource-rich environments.
• Previous models often used artificial bounding terms to achieve coexistence.

Purpose of the Study:

• To investigate how adaptive predator-induced and fitness-dependent defense mechanisms influence predator coexistence.
• To explore coexistence without relying on artificial bounding terms.
• To analyze the impact of adaptivity on invasion dynamics.

Main Methods:

• Incorporation of adaptive defense mechanisms into an intraguild predation model.
• Utilizing numerical bifurcation software to analyze parameter spaces for coexistence.
• Distinguishing between two adaptation parameters under varying environmental conditions.
• Examining the effect of adaptivity on dispersal and invasion waves in a 1D domain.

Main Results:

• Adaptive defense significantly expands parameter ranges that allow for predator coexistence.
• The reactivity-accuracy trade-off in adaptation is environment-dependent.
• Adaptivity's impact on dispersal alters the speed and shape of invasion waves.
• A system that is locally adaptive can exhibit transient global maladaptation.

Conclusions:

• Adaptive defense is a crucial factor for predator coexistence in intraguild systems.
• Environmental conditions dictate the nature of adaptive trade-offs.
• Understanding adaptivity's role in dispersal is key for predicting biological invasion patterns.
• Local adaptation does not guarantee global stability, especially in transient dynamics.