As the sun rises over the Kalahari Desert, meerkat groups emerge from their burrows and gather closely, turning their bodies toward the warmth of the early light. These quiet morning moments are more than a way to warm up; according to researchers from the University of Konstanz, the Max Planck Institute of Animal Behavior, and the University of Zurich, they also offer a window into how meerkats manage their social lives. The team studied a type of soft sound known as a “sunning call,” made while meerkats sunbathe together in the morning. The study, recently published in Behavioural Ecology, explores the concept of “vocal grooming”, a form of social bonding achieved through sound rather than physical touch. This work is part of the HFSP-supported project Communication and Coordination Across Scales (CCAS), which explores how social animals use vocal communication to coordinate with one another across different situations and species.
Meerkats live in highly cooperative groups with a clear dominance hierarchy. Typically, a dominant breeding pair leads the group, while lower-ranking members help raise young and defend territory. Physical grooming, in which individuals touch one another’s fur or skin to remove parasites, is one way animals maintain social relationships, but it takes time and requires close contact. The HFSP Research Grant team argues that sunning calls may work as a kind of grooming-at-a-distance, using sound to stay connected and maintain relationships.
To test this idea, scientists carried out playback experiments at the Kalahari Research Centre in South Africa. They recorded sunning calls from individual meerkats, then played them back to other group members and measured their responses. The results revealed that social factors influence responsiveness. Subordinate meerkats increased their calling when they heard dominant individuals, while dominant animals changed their behaviour much less in response to subordinates. Females also responded more strongly than males.
Interestingly, social bond strength had further and somewhat surprising effects. Initially, the researchers expected that individuals would respond strongly to closely bonded groupmates; however, the results suggested the opposite. Subordinates tended to be more responsive to calls of dominants with whom they had weaker social bonds. This suggests that sunning-call vocal exchanges may be especially useful for stabilizing these important yet weak social ties. Overall, the study shows that meerkat calls are not just background chatter. They fulfill social functions and may help reduce tension, strengthen group cohesion, and allow animals to navigate a complicated social system through sound alone.