Drifting behaviour as an alternative reproductive strategy for social insect workers

Area of Science:

• Behavioral Ecology
• Evolutionary Biology
• Insect Social Behavior

Background:

• Eusocial insect workers are traditionally defined by restricted reproduction.
• Worker reproduction in foreign colonies suggests higher potential for selfish interests.
• The decision-making processes underlying worker reproduction remain largely unknown.

Purpose of the Study:

• To investigate the reproductive decisions of workers in the bumblebee Bombus terrestris.
• To assess the extent of workers' reproductive options beyond their native colony.
• To understand the role of drifting as a strategy for worker reproduction.

Main Methods:

• Monitoring of worker movements between bumblebee colonies.
• Analysis of drifting behavior in both fertile and infertile workers.
• Correlation of worker fertility with propensity for drifting and reproduction in foreign colonies.

Main Results:

• Drifting is a dynamic behavior widely expressed by both fertile and infertile workers.
• High fertility significantly influences a worker's tendency to drift and reproduce in host colonies.
• Drifting by fertile workers indicates complex decision-making related to in-nest reproductive competition.

Conclusions:

• Drifting serves as a distinct strategy for fertile bumblebee workers to circumvent in-nest competition.
• Worker reproduction is not always restricted, and alternative reproductive strategies exist.
• This study highlights the importance of overlooked strategies in workers asserting reproductive interests within eusocial systems.