Small workers are more persistent when providing and requiring help in a monomorphic ant

Area of Science:

• Behavioral Ecology
• Insect Social Behavior
• Evolutionary Biology

Background:

• Ants exhibit complex social structures and behaviors, with body size often influencing task allocation in polymorphic species.
• Formica cinerea ants, despite having monomorphic workers, display significant size variation, prompting investigation into size-dependent behavioral differences.

Purpose of the Study:

• To investigate whether body size influences foraging ant behavior during nestmate rescue in Formica cinerea.
• To analyze size-related differences in rescue activity frequency, duration, and the behavior of trapped individuals.

Main Methods:

• Comparative analysis of large and small Formica cinerea worker behavior during simulated entrapment and rescue scenarios.
• Quantification of rescue activity, time to initiate rescue, and duration of rescue efforts for different worker sizes.
• Assessment of the activity levels of trapped workers based on their body size.

Main Results:

• No significant difference in the frequency or initial delay of rescue attempts between small and large Formica cinerea workers.
• Small workers demonstrated significantly longer rescue durations compared to large workers.
• Trapped small workers exhibited higher activity levels than trapped large workers.

Conclusions:

• While Formica cinerea lacks size-based specialization in initiating rescues, smaller workers display greater behavioral persistence.
• Size variation in Formica cinerea workers influences rescue behavior, with smaller individuals showing prolonged engagement and higher activity when trapped.
• These findings underscore the importance of studying among-individual behavioral variation in social insects, even in species with seemingly uniform worker sizes.