Mediators of dominance and reproductive success among queens in the cyclically polygynous Neotropical bumble bee Bombus atratus Franklin

Bombus atratus, a bumble bee found throughout much of South America, undergoes periods of polygyny during its colony cycle, which is often perennial. This temporary polygynous phase persists as multiple queens compete fiercely to become the sole reproductive. The outcome of these battles is death or expulsion from the nest of all but one of the queens, representing an extreme form of conflict of reproductive interests. We examined various factors which may influence survival and succession of rival B, atratus queens during a polygynous phase of a colony found in southern Brasil. Queens exhibiting greater ovarian development and a higher frequency of inter-queen aggression in the early period of polygyny survived significantly longer. Body size did not appear to contribute to the outcome of queen survival.