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The Sinister Side of Gentle-Looking Meerkats Brings Benefits


Image credit: J P via Flickr.

Alpha meerkat females, though have gentle-looking, have their sinister side: They will make sure they are on the top mongoose by killing and even eating their grandchildren. The sinister side of Timon’s cuddly kind has been published in Nature Communications last month.

Wild meerkats (Suricata suricatta) live in groups (called gangs or mobs) with a dominant breeding pair and some adult helpers. The superfamilies are cooperative and can contain members of up to 50 and the subordinates females will still try to breed in spite of the alpha’s monopoly. Dominant meerkats control breeding within their group by applying violence: they banish and attack any other females (their daughters) who attempt to reproduce and kill the offspring of their daughters.

Yet, they do in this way to ensure there are plentiful resources for the alpha pair’s pups. “The meerkat way of life is a paradox”, says Matt Bell at the University of Edinburgh. Such cannibalistic, but effective strategy has also been found in other animals, such as bees and ants. “Benefits have always been assumed, however, we never clearly confirmed them,” Bell explains to the Washington Post.

In order to measure the impact of suppressing subordinate reproduction in a direct way, Bell and his coworkers gave contraceptive injections of Depo-provera to all 35 adult female helpers in six groups of meerkats in the Kuruman River Reserve in South Africa. They did the injection during the course of three breeding attempts and ensured that the subordinate females can’t reproduce in the course of six to nine mouths. For comparison, they injected all 38 subordinate females in another six groups with saline solution.

During this period, dominant females became less aggressive toward the treated female helpers. They also foraged more and gained more weight, and also delivered heavier offspring who grew faster. The adult helpers experienced fewer evictions and less violence than usual from the alpha females, and they offered better care and more food for the offspring of the alpha female.

This work supported assumptions that Kalahari Desert alpha female flourishes when she keeps the sole right of breeding. “Dominant animals are worse off when subordinates in their mob attempt to breed, and this explains why they suppress others brutally much of the time,” notes Bell in a news release. “We expected the result, but the impact really exceeded our expectations.”

Image: J P via Flickr CC BY 2.0