Data from: Life-history strategy and behavioral type: risk-tolerance reflects growth rate and energy allocation in ant colonies

Despite the recent interest in animal personality and behavioral
syndromes, there is a paucity of explanations for why distinct behavioral
traits should evolve to correlate. We investigate whether such
correlations across apparently distinct behavioral traits may be explained
by variation in life history strategy among individual ant colonies. Life
history theory predicts that the way in which individuals allocate energy
towards somatic maintenance or reproduction drives several distinct traits
in physiology, morphology, and energy use; it also predicts that an
individual's willingness to engage in risky behaviors should depend
on reproductive strategy. We use Temnothorax ants, which have been shown
to exhibit ‘personalities’ and a syndrome that may reflect risk tolerance
at the colony level. We measure colonies' relative investment in
growth rate (new workers produced) compared to reproductive effort (males
and queens produced). Comparing sterile worker production to reproductive
alate production provides a direct measure of how colonies are investing
their energy, analogous to investment in growth versus reproduction in a
unitary organism. Consistently with this idea, we found that behavioral
type of ant colonies was associated with their life history strategy:
risk-tolerant colonies grew faster and invested more in reproduction,
whereas risk-averse colonies had lower growth rate but invested relatively
more in workers. This provides evidence that behavioral syndromes can be a
consequence of life-history strategy variation, linking the two fields and
supporting the use of an integrative approach.