Directional raids by army ants as an adaption to patchily distributed food: a simulation model

Area of Science:

• Ecology
• Animal Behavior
• Computational Biology

Background:

• Neotropical army ants (subfamily Ecitoninae) forage using directional raids, forming long columns.
• An alternative foraging strategy is radial raiding, expanding outwards symmetrically.
• Understanding these strategies is key to army ant ecology.

Purpose of the Study:

• To compare the effectiveness of directional versus radial raiding strategies in army ants.
• To evaluate foraging efficiency under different food distributions and qualities.
• To determine the adaptive significance of directional raiding.

Main Methods:

• Utilized agent-based modeling software to simulate army ant behavior.
• Compared directional and radial raiding modes in silico.
• Analyzed outcomes based on varying food patch abundance and quality.

Main Results:

• Radial raiding outperformed directional raiding in low-quality food patches, irrespective of abundance.
• Directional raiding was more effective in rich food patches.
• Radial raiding demonstrated superior energy efficiency across a broad range of conditions.
• Directional raiding yielded higher food yield per unit area covered.

Conclusions:

• Directional raiding by army ants appears to be an adaptation to habitats with abundant, high-quality food resources.
• The choice of foraging strategy is influenced by food patch quality and abundance.
• The findings align with the known ecological characteristics of army ants.