When searching for their favorite grub, those furry little creatures known as meerkats emit distinct chirps that let them identify their compatriots as if by name, new research suggests.
"Called a 'close call,' this call plays a role in group cohesion, in keeping the group together," study researcher Simon Townsend, of the University of Zurich in Switzerland, told LiveScience. "They use that call as a way to keep track of who is there." [Dissecting Decibels: The Loudest Animals (Infographic)]
They might also use the close calls to avoid dominant members of the group, or those that are better foragers. "Meerkats do have individualized relationships with one another. They are cooperative breeding species, so they have to coordinate activities in the group," Townsend said.
Messing with meerkats
Townsend and his colleagues recorded close calls made by a group of meerkats in the wild. Then they played back the calls to the group of foraging meerkats. Sometimes, the team tried to trick the meerkats by playing the same call on one side of them, followed a few seconds later by playing the same call on the opposite side, a move that would have been impossible for an actual meerkat emitting the call.
"Instead of finding a specific social context, we just mimicked a socially plausible and socially implausible scenario," Townsend said. "They responded more strongly to the incongruent situation than the completely plausible scenario."
When played the same call from different areas, the animals seemed to be confused. The researchers say this means they recognized that that call was specific to one individual meerkat, and so realized it would have been physically impossible for that individual meerkat to move that far so quickly.
The meerkats add to a long list of animals that can tell their familiars apart, from mammals to wasps (which tell each other apart by color variations) to sperm whales, which have individual accents.
Humans take this ability for granted. For example, we can easily come to recognize the voice of a radio personality, or even the Moviefone guy, without ever even seeing what they look like. Townsend even suggests that perhaps these vocal identification communications use the same underlying brain mechanisms in different mammalian species.
The study was published today (Oct. 11) in the journal Biology Letters.