Predator interference alters foraging behavior of a generalist predatory arthropod

Area of Science:

• Ecology
• Behavioral Ecology
• Predator-Prey Dynamics

Background:

• Predator interactions within foraging patches influence patch use and functional responses.
• Mutual interference among predators is a key factor shaping these interactions.
• Few studies link predator patch departure rates with feeding rates.

Purpose of the Study:

• To investigate the relationship between patch departure rates and food consumption in the hunting spider, Pardosa milvina.
• To determine how predator density and prey availability affect foraging decisions.
• To identify the most appropriate functional response model for this species.

Main Methods:

• Field enclosures were used to manipulate prey and predator densities.
• Laboratory data were used to fit and compare alternative functional response models.
• Patch departure rates and predator abundance were quantified.

Main Results:

• Prey availability was the primary driver of patch departure.
• Higher predator densities led to a greater proportion of predators leaving the foraging patch.
• Functional response analysis revealed significant interference, reducing feeding rates even with constant area per predator.

Conclusions:

• Feeding rates directly influence patch movement dynamics in Pardosa milvina.
• Interference among predators drives them to seek foraging sites that balance agonistic interactions with prey encounter rates.
• This study highlights the importance of integrating patch use and functional response in understanding predator foraging.