Marmosets can learn, adopt new dialects

Like many mammals, the marmoset, a small monkey native to Central and South America, communicates using regional dialects. Their calls and songs vary from one location to another.

Scientists have previously studied marmoset dialects, but, until now, it wasn't clear how these regional differences develop -- whether they're caused by genetic differences, environmental factors or social learning.

To better understand the phenomenon, scientists recorded the calls of captive marmosets before and after relocating them to different populations. Their analysis showed that monkeys moving from one population to another altered their dialect. They tweaked their old calls and adopted the vocal patterns of their new neighbors.

Scientists detailed the results of their analysis this week in the journal PLOS One.

"We could clearly show that the dialects of common marmosets are learned socially," Yvonne Zürcher, an anthropologist at the University of Zurich in Switzerland, said in a news release. "If their dialects were genetically determined, moving to a new place wouldn't cause any change in calls. The changes can't be explained by differences in the environment either."

It's not clear what advantages this ability offers migrating marmosets, but scientists suspect sounding like the locals increases a newcomer's odds of landing a mate.

"In any case, it's no surprise that we found evidence of socially learned dialects in common marmosets," said senior study author Judith Burkart.

According to Burkart, marmosets are quite similar to humans in many of their behaviors. For example, they raise their young with communal assistance. It's possible dialects help reinforce this group cohesion and cooperation.

Authors of the new study suggest further research in marmoset vocal patterns could offer new insights into the evolutionary origins of language.