Female meerkats evict other females and kill their babies. Now, researchers know why

Brendan Rascius
Wed, December 13, 2023 



With their whiskered faces and high-pitched calls, meerkats don’t appear particularly menacing.

But, female meerkats are, in fact, capable of vicious behavior, including harassing rivals, exiling them and even eating their offspring.

Now, researchers believe they know why the animals — members of the mongoose family found throughout southern Africa — have such bloodthirsty streaks.

Dominant female meerkats display a unique gene expression not seen in lower-status individuals, according to a preprint study posted to the server bioRxiv on Dec. 3.

Female meerkats fight ferociously to reproduce as they live alongside males in matriarchal groups called mobs.

Dominant females physically compete with other females to repress their reproduction and sometimes resort to “targeted eviction and infanticide if subordinate animals attempt to breed,” researchers said.

This competition causes a large skew in reproductive success, leaving most subordinates bearing no offspring while dominant females have multitudes, including one who successfully reared 72 pups.

This kind of drastic skew is “unusual in mammal social groups,” Jenny Tung, a Duke University professor and co-author of the study, told Live Science.

Intent on examining the underlying cause of this phenomenon, researchers studied the behavior of 129 South African meerkats between 2017 and 2020.

The animals, which were accustomed to humans, were regularly captured and sedated for blood sample collections.

The blood samples revealed “a strong signature of dominance in female meerkats but not male meerkats,” which may be related to certain “status-associated genes,” researchers said.

For example, the high-ranking females had higher levels of androgen, which is associated with aggressiveness, according to a 2016 study published in the journal Nature.

“These raised androgen concentrations may explain female aggressiveness in this species,” according to the study, “and give dominant breeders a heritable mechanism for their daughters’ competitive edge.”

They also showed evidence of an “upregulation” of genes related to inflammatory response, indicating they can fight off infections better than subordinate females.

These genetic differences may help female meerkats reach the top of the pecking order — and stay there, researchers said.

“Our results indicate that social status is important for how immune genes are regulated, not only in primates, but probably more broadly among social animals,” Tung told Live Science. “And the way this relationship works probably depends on how status is determined and how intensively status shapes reproductive competition.”