Modelling foraging competition between solitarious and gregarious organisms in increasingly heterogeneous...

Area of Science:

• Ecology
• Evolutionary Biology
• Behavioral Ecology

Background:

• Density dependent phase polyphenism results in distinct phenotypes from a single genotype based on population density.
• Locusts exemplify this, exhibiting solitarious (avoiding others) or gregarious (attracted to others) phases, influenced by food distribution.
• While gregarisation aids predator avoidance, its foraging benefits in varied environments remain unclear.

Purpose of the Study:

• To investigate the impact of gregarisation on foraging efficiency in environments with increasing spatial heterogeneity.
• To model the interplay between phase polyphenism and foraging strategies.

Main Methods:

• Utilized a partial differential equation model to simulate foraging in heterogeneous environments.
• Analyzed steady-state foraging advantage by measuring per-capita food contact.
• Conducted parameter sensitivity analysis to identify influential model parameters.

Main Results:

• Gregarious behavior provides a foraging advantage over solitarious behavior in increasingly food-heterogeneous environments during the aggregation phase.
• This advantage is inherent to the gregarious/solitarious behavioral dynamic.
• The benefit persists irrespective of dispersal rates or interaction strengths, provided the polyphenic behavior is present.

Conclusions:

• Gregarisation enhances foraging success in patchy environments, a key evolutionary advantage.
• The study highlights the ecological significance of phase polyphenism in locusts.
• Understanding these dynamics is crucial for predicting locust behavior and managing outbreaks.