Abstract
Bumble bees (Bombus impatiens) undergo a radical transformation in social dynamics as a natural part of their colony life cycle. Early in the season, bumble bee societies are eusocial and contain a reproductive queen and functionally sterile workers. As the colony grows, the colony transitions to a competition phase in which reproductive division of labor breaks down and some workers activate their ovaries and lay unfertilized, male-destined eggs. This transition represents a key shift in colony organization, but its underlying social dynamics, including the relationship between individual- and colony-level behavior, are poorly understood. Using multianimal pose tracking to quantify social interactivity and related movement dynamics, we compared queenright and queenless colonies that capture these distinct cooperative and competitive phases of the colony life cycle. Queenright colonies displayed highly centralized social networks in which the queen received, rather than initiated, the majority of social interactions. In contrast, queenless colonies displayed higher worker interaction rates, and a subset of workers exhibited queen-like social behaviors and higher reproductive potential relative to nestmates. The unmasking of these “influencers” in a queenless, competitive context transformed the colony’s social network from a centralized to distributed social organization with higher overall network efficiency. Thus, the bumble bee queen masks a hidden relationship between worker influence and reproductive potential that underlies their latent social flexibility. In the absence of a queen, the colony social structure is transformed, revealing that significant modifications in information transfer can accompany shifts in colony social organization and highlighting a novel layer of resilience in this social system.
Competing Interest Statement
The authors have declared no competing interest.