THURSDAY, 10 AUGUST 2006
Meerkats live in complex societies in which only one pair of individuals, the dominant pair, actually breed. The other meerkats are subordinate and often act as 'nurses', helping the dominant pair to raise their young.
The new research by Andrew Young's team at the Department of Zoology was published in Proceedings of the National Academy of Sciences. Their work shows that the dominant female drives out the female subordinates during the latter stages of her pregnancy. She attacks and chases them repeatedly, typically throwing them out of the group for three weeks.
As a result of this treatment, the subordinate females experience huge increases in their levels of stress hormones. This reduces their fertility: fewer babies are conceived, and more of those that are conceived do not survive to birth.
As a result of the dominant female's behaviour, her babies do not have to compete with other pups for the attentions of the nurse meerkats and are therefore likely to be better cared for.
Previous work by Young's team, published in Biology Letters in March this year, showed that subordinate females that do manage to become pregnant will kill the babies of other females, including those of the dominant female, in order to advance their own babies' positions. By driving out the subordinates when she becomes pregnant, the dominant female prevents them from attacking her babies.
The research was conducted as part of the Kalahari Meerkat Project, a decade-long project conducted in the Kuruman River Reserve, South Africa. The Project is one of four run by the Large Animal Research Group at the Department of Zoology.
The paper in PNAS
The earlier paper in Biology Letters
The Large Animal Research Group website
Written by Michael Marshall