For years, biologists believed that the transition of power in naked mole rat colonies was a violent, inevitable necessity. In these unique societies, a single queen maintains her dominance by suppressing the reproductive capabilities of all other females. When a queen dies, the resulting power vacuum typically triggers “queen wars”—bloody, chaotic battles where females fight for the right to breed, often resulting in injury or death to both adults and offspring.
However, new research from the Salk Institute for Biological Studies has revealed a surprising alternative: naked mole rats are capable of a peaceful transfer of power.
The Rigid Hierarchy of Eusocial Societies
Naked mole rats are eusocial, a social structure most commonly associated with bees and ants. In these colonies, the population is strictly divided into two groups:
– The Queen: The sole reproductive female.
– The Workers: Non-reproductive individuals that serve the colony.
This rigid system is highly efficient in the stable, arid environments of sub-Saharan Africa where these rodents live. However, this biological “monarchy” carries significant evolutionary risks. Because all offspring share the genes of a single mother, the colony lacks genetic diversity, making them highly vulnerable to sudden diseases or environmental shifts. Furthermore, the energy spent by the queen to physically enforce her dominance can be taxing and dangerous for the colony members.
A Discovery in the Lab
To investigate whether these animals possessed more social flexibility than previously thought, researchers Janelle Ayres and Shanes Abeywardena conducted a long-term study starting in 2019. They monitored a small, stable family known as the “Amigos” colony, which consisted of a queen named Teré, one reproductive male, and four pups.
To test for succession without the trauma of death, the team simulated environmental stressors. The breakthrough occurred when the researchers relocated the colony to a new vivarium. This change in environment caused the queen, Teré, to temporarily cease reproduction for nearly a year.
Instead of the expected outbreak of violence, the colony underwent a smooth transition:
1. Two of Teré’s daughters began reproducing sequentially.
2. One daughter, named Arwen, eventually assumed the role of the sole reproductive queen.
3. This transition occurred without any documented fighting or “wars” among the females.
Why This Matters for Biology
This finding challenges the long-held assumption that naked mole rat hierarchies are purely enforced through aggression. The ability to undergo “peaceful succession” suggests that these animals possess a level of reproductive flexibility that scientists had not previously appreciated.
“We found that naked mole rats are capable of peaceful queen succession, suggesting these animals have greater reproductive flexibility than previously appreciated,” says Janelle Ayres, a molecular and systems physiologist at the Salk Institute.
This discovery opens new questions about how social animals manage power. It suggests that even in highly rigid, “dictatorial” social structures, there may be biological mechanisms that allow for stability and transition without the need for constant conflict.
Conclusion: By demonstrating that queen succession can occur without violence, this study reveals that naked mole rats possess a more adaptable social structure than once thought, offering new insights into the complexities of eusocial evolution.
