Predator-prey pursuit-evasion games in structurally complex environments

Area of Science:

• Ecology
• Behavioral Ecology
• Biomechanics

Background:

• Predator-prey interactions are often constrained by environmental geometry.
• Habitat structure significantly impacts perception and behavioral responses.
• The role of microtopography in predator-prey dynamics remains understudied.

Purpose of the Study:

• To quantify the influence of forest leaf litter microtopography on predator-prey pursuit-evasion trajectories.
• To investigate how substrate geometry affects the behavioral strategies of wolf spiders (Pardosa sp.) and wood crickets (Nemobius sylvestris).

Main Methods:

• Collected and analyzed forest leaf litter samples using laser scanning for microtopography mapping.
• Identified litter structuring patterns via height transects and experimental semi-variograms.
• Recorded and analyzed pursuit-evasion sequences in controlled arenas with varying substrates (flat paper vs. leaf litter).

Main Results:

• Leaf litter topography was characterized by compaction index and contiguous flat surface length, differing between summer and winter samples.
• A strong correlation was found between the leaf litter's structural unit size and the initiation distance of pursuit and escape behaviors (approximately 3 cm).
• Leaf litter significantly altered pursuit-evasion dynamics, reducing pursuit initiation likelihood, halving pursuit/escape distances, equalizing predator-prey distances, and nearly eliminating secondary pursuits.

Conclusions:

• Habitat geometry, specifically forest leaf litter microtopography, profoundly modulates predator-prey interaction rules.
• The physical structure of the environment plays a critical role in shaping the dynamics of pursuit and evasion behaviors.
• Findings highlight the importance of considering environmental architecture in ecological and evolutionary studies of animal behavior.