Recognizing other individuals from their voices is second nature to humans. Certain primates also have this ability. Whether other mammals that live in social groups are also able to do so, however, is unclear. Like with primates, vocal communication is vital for meerkats. They coordinate their activities with calls, such as to warn other group members of approaching predators, for instance, and thus stick together as a group. Behavior biologists from the University of Zurich have already managed to decipher many calls in meerkat communication. Now, however, they have become the first to establish that meerkats are able to distinguish individual calls.
Behavior biologists from the University of Zurich simulated the simultaneous presence of a group member in two different places in a novel playback experiment on wild meerkats in the Kalahari Desert of Southern Africa. Meerkats were played two different calls from the same group member one after the other. This physically impossible scenario was contrasted with a physically possible scenario where the meerkats heard calls from two different group members. According to the researcher in charge, Simon Townsend, the meerkats responded more strongly to the impossible scenario than to calls from two different individuals. The scientists concluded that meerkats can tell the individual members of a group apart from their calls.
Meerkat colonies are highly organized and essentially divide their work into three roles: lookouts, hunters and babysitters. Until now, we had assumed that meerkats assigned their conspecific counterparts to these groups but do not differentiate them from one another. With this experiment, however, the behavior biologists have proved this assumption wrong. In both scenarios, calls from an equal-ranking group member were used. “We take it that meerkats can tell the individual group members apart. However, we don’t yet know which cognitive mechanisms underlie this ability. Or whether the ability to tell group members apart is merely linked to auditory cues,” says Townsend.
Simon W. Townsend, Colin Allen, Marta B. Manser: A simple test of vocal individual recognition in wild meerkats, in: Biol. Lett. (2011) 00, 1–4, Doi:10.1098/rsbl.2011.0844