Collective decision-making when quantity is more important than quality: Lessons from a kidnapping social parasite

Identifying the general principles that shape mechanisms of collective decision-making requires studies that span a diversity of ecological contexts. However, collective decision-making has only been explored in a handful of systems.

Here, I investigate the ecologically mediated costs and benefits of collective-decisions by socially parasitic kidnapping ants (Temnothorax americanus) over where to launch raids to steal host brood.

I first investigate their sampling strategies and preferences with choice-tests. Using more realistic spatial scales, I confirm the findings of others that colonies use a sequential choice strategy, and do not compare options simultaneously. I then ask which ecological conditions could favor the evolution of this strategy by testing the following hypotheses from optimal foraging and mate choice theories: (1) raiding decisions are time constrained or (2) search payoffs are low due to resource uniformity.

Spatial distribution and phenological data on nes...