Abstract
Workers of the ant Cardiocondyla elegans drop female sexuals into
the nest entrance of other colonies to promote outbreeding with
unrelated, wingless males. Corroborating results from previous years we
document that carrier and carried female sexuals are typically related
and that the transfer initially occurs mostly from their joint natal
colonies to unrelated colonies. Female sexuals mate multiply with up to
seven genetically distinguishable males. Contrary to our expectation,
the colony growth rate of multiple-mated and outbred female sexuals was
lower than that of inbred or single-mated females, leading to the
question of why female sexuals mate multiply at all. Despite the obvious
costs, multiple mating might be a way for female sexuals to “pay rent”
for hibernation in an alien nest. We argue that in addition to evading
inbreeding depression from regular sibling mating over many generations,
assisted dispersal might also be a strategy for minimizing the risk of
losing all reproductive investment when nests are flooded in winter.
KEYWORDS Formicidae, Hymenoptera, population structure, mating
behavior, outbreeding, polyandry