From Fear to Feast: Rattlesnakes Navigate the Landscape of Fear to Optimize Foraging

Area of Science:

• Ecology
• Behavioral Ecology
• Predator-Prey Dynamics

Background:

• Optimal foraging theory predicts mesopredators balance prey abundance with predation risk.
• Understanding environmental influences on mesopredator spatial and temporal activity is crucial for predicting ecological interactions.

Purpose of the Study:

• To investigate how environmental factors influence western diamond-backed rattlesnakes' (Crotalus atrox) ability to minimize overlap with predators and maximize overlap with prey.
• To test if rattlesnake activity patterns align with optimal foraging theory by assessing prey encounter and predator risk probabilities.

Main Methods:

• Utilized 3D printed rattlesnake replicas and game cameras over two years in West Texas to quantify spatiotemporal factors of prey availability and predation risk.
• Radiotracked 25 free-ranging rattlesnakes to collect activity and microhabitat selection data.
• Applied random forest algorithms to predict predation and prey encounter probabilities based on camera data for radiotracking events.

Main Results:

• Time of day, month, vegetation structure, and concealment percentage significantly influenced both predation and prey encounter probabilities.
• Rattlesnakes demonstrated a higher probability of prey encounter compared to predator encounter during their active periods.
• Activity patterns were strongly associated with environmental variables, supporting optimal foraging strategies.

Conclusions:

• Western diamond-backed rattlesnakes adjust their activity to align with periods and locations offering a higher likelihood of encountering prey while reducing the risk of predation.
• Mesopredators effectively enhance prey capture success and minimize predator detection through strategic environmental choices, validating optimal foraging theory in natural settings.