Dominant female meerkats (Suricata suricatta) will kill any offspring that aren’t hers to maintain control of the mob. (Image credit: The Speedy Butterfly/Getty Images)
Meerkats possess an undeniable cuteness, but the dominant females have a dark side. They are notoriously deadly and will kill female relatives and eat their offspring to suppress reproduction and eliminate future competition. Now, scientists may finally know what helps these murderous matriarchs become dominant — and stay on top.
In a new preprint study posted to the online server bioRxiv, researchers have identified a sex-specific signature of dominance in female meerkats that gives them super-immunity, possibly helping them to maintain their dominant position.
These immune genes were found to closely resemble immunity genes seen in wild male baboons (Papio) where physical competition is crucial to determining rank hierarchies and mating. This suggests immunity and social status are intertwined.
Meerkats (Suricata suricatta) live in family groups, known as mobs, of up to 50 individuals and are led by a female matriarch, who dominates up to 80% of breeding to maintain her control. If a subordinate female attempts to breed, she is evicted from the social group and any offspring are killed. Subordinates of both sexes assist in rearing, enabling dominant females to breed multiple times a year and often live for longer than subordinates.
As a result, there is often an extreme reproductive skew in female meerkats that is unique to the species. Scientists found evidence of one alpha female rearing up to 72 offspring during her lifetime, while lower-ranking females within the social group produced no surviving young. Skewed reproduction is also recorded in male meerkats, with dominant males fathering the most pups.
Dominant female meerkats control around 80% of the breeding in the mob. (Image credit: siete_vidas/Shutterstock)
“In meerkats, females compete for mating opportunities — and can either be very successful, or never have offspring at all — which is a pattern that is unusual in mammal social groups.” Jenny Tung, professor of evolutionary anthropology at Duke University and co-author of the study, told Live Science.
The study into 129 wild meerkats (69 males and 60 females) over a three-year period at Kuruman River Reserve in South Africa’s Northern Cape Province monitored behavior and agonistic interactions to determine dominance status.
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The researchers also took regular blood samples, including at the points where a subordinate became the dominant meerkat and in the weeks and months that followed this societal rejig.
The blood samples showed dominant males and females had higher levels of cortisol — a hormone associated with stress. However dominant female meerkats also had higher androgen levels — a hormone that contributes to growth and reproduction — than their same-sex subordinates, as well as a higher body mass.