Competition in a group of equal foragers

Area of Science:

• Ecology
• Behavioral Ecology
• Mathematical Biology

Background:

• Foraging behavior is central to animal ecology.
• Group living is common, but its benefits, especially in foraging, are debated.
• Understanding gain accumulation in different social contexts is key.

Purpose of the Study:

• To develop a stochastic model of gain accumulation for competitors in a patchy environment.
• To analyze how group size and patch variability affect individual foraging gains and correlations.
• To compare the foraging efficiency and gain variance of solitary versus group foragers.

Main Methods:

• Utilized renewal process theory to model individual gain based on prey encounter waiting times.
• Developed a model where waiting times depend on the number of foragers, parameterized by a single variable.
• Analyzed the impact of constant versus variable patch sizes on gain correlations.

Main Results:

• Negative correlations in gains between foragers occur in constant patch sizes, strongest in small groups.
• Positive gain correlations emerge with increased patch size variation, regardless of group size.
• Individual gain variance increases monotonically in groups, unlike solitary foragers where it decreases over time.

Conclusions:

• Solitary foragers may achieve lower gain variance than group members, depending on patch departure rules.
• The potential for solitary foragers to deplete patches further questions the sole evolutionary advantage of foraging groups.
• Grouping behavior's evolution may rely on factors beyond simple foraging efficiency.