Data from: The influence of stress hormones and aggression on cooperative behaviour in subordinate meerkats

In cooperative breeders, aggression from dominant breeders directed at
subordinates may raise subordinate stress hormone (glucocorticoid)
concentrations. This may benefit dominants by suppressing subordinate
reproduction but it is uncertain whether aggression from dominants can
elevate subordinate cooperative behaviour, or how resulting changes in
subordinate glucocorticoid concentrations affect their cooperative
behaviour. We show here that the effects of manipulating glucocorticoid
concentrations in wild meerkats (Suricata suricatta) on cooperative
behaviour varied between cooperative activities as well as between the
sexes. Subordinates of both sexes treated with a glucocorticoid receptor
antagonist (mifepristone) exhibited significantly more pup protection
behaviour (babysitting) compared to those treated with glucocorticoids
(cortisol) or controls. Females treated with mifepristone had a higher
probability of exhibiting pup food provisioning (pup-feeding) compared to
those treated with cortisol. In males, there were no treatment effects on
the probability of pup-feeding, but those treated with cortisol gave a
higher proportion of the food they found to pups than those treated with
mifepristone. Using 19 years of behavioural data, we also show that
dominant females did not increase the frequency with which they directed
aggression at subordinates at times when the need for assistance was
highest. Our results suggest that it is unlikely that dominant females
manipulate the cooperative behaviour of subordinates through the effects
of aggression on their glucocorticoid levels and that the function of
aggression directed at subordinates is probably to reduce the probability
they will breed.