Abstract:
There is increasing evidence that some vertebrates can adjust their growth rate in
relation to changes in the social context that affect their probability of breeding.
Here, we show that, in meerkats (Suricata suricatta), which are singular cooperative
breeders, subordinate females increase in body mass after their father is replaced as
the dominant male in their natal group by an immigrant male, giving them regular access
to an unfamiliar and unrelated mating partner, while their brothers showed no
similar increase nor did subordinate females living in other stable groups (where male
immigration did not occur did) in this time period. Moreover, subordinate females
showed a greater increase in growth rate when their father was succeeded by an
unfamiliar immigrant male than when he was replaced by a familiar male who was
already resident. These results suggest that female meerkats can adjust their rate of
growth to changes in the kinship composition of their groups that provide them with
increased access to unrelated breeding partners, which may occur in other mammals
as well when breeding opportunities change.