Compensatory Foraging in Stoichiometric Producer-Grazer Models

Area of Science:

• Ecology
• Theoretical Ecology
• Aquatic Ecology

Background:

• Nutritional constraints and elemental mismatches between trophic levels impact grazer populations.
• Grazing species, such as Daphnia, employ optimal foraging strategies, including compensatory feeding, to overcome dietary limitations.

Purpose of the Study:

• To develop and compare two stoichiometric producer-grazer models: one with fixed energetic foraging costs and another with variable costs dependent on food nutritional content.
• To investigate the benefits of stoichiometric compensatory foraging behaviors on grazer populations under varying environmental conditions.

Main Methods:

• Development of two stoichiometric producer-grazer models.
• Analysis of how variable energetic foraging costs influence cell quota-dependent predation behaviors.
• Comparison of model outcomes under different light and nutrient availability scenarios.

Main Results:

• Variable energetic foraging costs lead to cell quota-dependent predation.
• In low-light conditions, fixed energetic foraging is optimal regardless of nutrient loads.
• In higher light and intermediate nutrient conditions, compensatory foraging provides an advantage to grazers.

Conclusions:

• Compensatory feeding behaviors benefit grazers when prey nutrient content is suboptimal (either too low or too high).
• Optimal foraging strategies are condition-dependent, influenced by environmental factors like light and nutrient availability.
• Stoichiometric models provide insights into the adaptive foraging strategies of grazers in response to nutritional variability.