Colony co-founding in ants is an active process by queens

Area of Science:

• Evolutionary biology
• Behavioral ecology
• Entomology

Background:

• Cooperative breeding, where individuals help others reproduce, can evolve if it offers fitness benefits over solitary breeding.
• Colony co-founding, a form of cooperative breeding in social insects, involves multiple queens establishing a new nest together.
• Previous research suggested ant colony co-founding might be a random process due to high queen density and limited nest sites.

Purpose of the Study:

• To experimentally investigate the nest-founding behavior of the black garden ant, Lasius niger.
• To determine if colony co-founding in ants is a random process or an active choice driven by queen interactions.
• To test the hypothesis that queens are mutually attracted, leading to group nest founding.

Main Methods:

• Newly mated Lasius niger queens were presented with a choice of two empty nesting chambers.
• Queen distribution between the chambers was recorded and compared to random allocation expectations.
• Experimental data on queen grouping patterns were analyzed to identify non-random associations.

Main Results:

• Lasius niger queens formed associations of varying sizes, with most queens choosing to group in a single chamber.
• The observed frequency of larger queen groups was significantly higher than what would be expected by random chance.
• This indicates that queens do not randomly assort into nests but actively form groups.

Conclusions:

• Colony co-founding in ants appears to be an active process driven by mutual attraction among queens.
• This active selection for co-founding suggests it may confer fitness advantages.
• Ecological factors in natural settings may still influence the frequency of queen encounters and subsequent co-founding.