Meeting Abstract
Queens of the seed-harvester ant Pogonomyrmex californicus vary geographically in their propensity to cooperate with each other when starting a new colony, leading to questions about the mechanisms that facilitate such grouping and cooperation. Given recent studies that show that ant colony mass-specific metabolic costs decline with group size, we tested the hypothesis that cooperation provides a metabolic advantage for queen pairs during colony founding. We determined that the most energetically intense period of nest initiation extends from the postmating period, through nest excavation, until the onset of brood-rearing. Correspondingly, both queens with an evolutionary history of cooperative nest-founding and queens that lack this history showed reduced mass-specific metabolic rates when paired together during the most energetically intense period. This effect occurred independently of any metabolic costs associated with locomotion. Collectively, our findings suggest that the simple act of grouping somehow provides a direct energetic benefit to queens during the energetically demanding life stage of colony founding, regardless of whether or not queens have actually evolved to cooperate during this period. This research was partially supported by NSF IOS 1558127.
