Nutritional state and collective motion: from individuals to mass migration

Area of Science:

• Movement ecology
• Animal behavior
• Collective motion

Background:

• Understanding how internal states influence animal movement is crucial for movement ecology.
• Nutritional state is a key internal factor affecting individual and collective animal behavior.
• Linking internal cues to external responses remains a significant challenge in movement ecology.

Purpose of the Study:

• To investigate the influence of nutritional state on individual and collective locust movement.
• To determine if diet-induced social interactions drive mass movement in locust hopper bands.
• To model the impact of nutritional status on locust migration dynamics.

Main Methods:

• Experimental observation of isolated and grouped locusts under varying nutritional conditions.
• Development of an experimentally parametrized model of locust interactions and motion.
• Analysis of how nutritional state and insect density affect movement patterns and coordination.

Main Results:

• Nutritional state has a minor impact on isolated locusts but significantly affects group behavior through inter-individual interactions.
• Cannibalism, driven by protein deprivation, appears to be a major factor in locust mass movement.
• The model predicts a transition in band speed and coordination with increasing density, influenced by interaction strength.

Conclusions:

• Nutrient-dependent social interactions are a key driver of collective motion in locusts.
• Individual nutritional status can profoundly impact large-scale locust migration.
• Dietary changes and resulting social interactions may trigger or modify locust swarm behavior.