[Animals] Monkeys change their ‘accent’ to avoid conflicts with other species, according to study

[#Steeven.™]

Strategy would allow them to understand each other better.

New research has found that monkeys will use another species' "accent" when entering their territory to help them understand each other better and potentially avoid conflict.

Published in the journal Behavioral Ecology and Sociobiology, the study is the first to show asymmetric convergence of calls in primates, meaning that one species chooses to adopt the call patterns of another species to communicate.

The study, co-authored by Dr. Jacob Dunn of Anglia Ruskin University (ARU), investigated the behavior of 15 groups of bald tamarins (Saguinus bicolor) and red-handed tamarins (Saguinus midas) in the Brazilian Amazon.

Red-handed tamarins are critically endangered and have one of the smallest ranges of any primate in the world, largely around the city of Manaus, while red-handed tamarins are found throughout the northeastern Amazon region.

The researchers found that when groups of red-handed tamarins entered shared territory with bald marmosets, the red-handed tamarins adopted the long calls used by bald marmosets.

Red-handed marmosets have greater vocal flexibility and use calls more often than bald marmosets, and scientists believe they could alter their calls to avoid territorial disputes over resources.

Lead author Tainara Sobroza, from the Instituto Nacional de Pesquisas da Amazonia, said: “When groups of tamarins move rapidly through the mature Amazon forest, it can sometimes be difficult to distinguish the species, but during our research we were surprised to find that they also they sound the same in the areas of the forest that coexist.

“We found that only red-handed marmosets change their calls to bald marmosets, and this only happens in places where they live together. It is not known with certainty why their calls converge in this way, but possibly it is to help with identification when defending territory or competing for resources. "

Co-author Dr. Jacob Dunn, associate professor of evolutionary biology at Anglia Ruskin University (ARU), said: “We have long known that when closely related species overlap in their geographic ranges, we are likely to see interesting evolutionary patterns. One example is the Galapagos finches, studied by Charles Darwin, whose beaks evolved to specialize in different foods on the islands to avoid competition.

In some cases, instead of diverging to become more different from each other, some closely related species converge to display similar traits. Our study is the first to show an asymmetric convergence of calls in primates, and the call of a species becomes the ‘lingua franca’ in shared territories.

"Because these tamarin species depend on similar resources, changing their 'accents' in this way is likely to help these small primates identify with each other more easily in dense forests and potentially avoid conflict."