Orangutans use slang to ‘show off their coolness’, study suggests

Our social environment shapes our vocabulary, whether it is the rapid change of patois of teenagers or the long-buried words found in a rural community. It seems that orangutans may also be influenced by such influences.

Researchers studying the alarm calls of wild communities of apes in Borneo and Sumatra have found that orangutans are able to come up with new versions of the calls.

The density of the local community affects whether the new versions stick or not.

The way I see it is that low densities of orangutans have a vocabulary that they use constantly. They are conservative, but once a new call variant is used, everyone hears it, and the variant is quickly incorporated, according to Dr Adriano Lameira, the first author of the research from the department of psychology.

Communication in high density orangutans is more like a noise. He said thatnovelty is at a premium, like in songbirds, and that individuals want to show off their coolness and how much of a rebel they are.

While social influences have been found to play a role in communication for animals including song birds and marmosets, the team behind the new research say it had been unclear whether the same was true for non-human apes.

In the journal Nature Ecology and Evolution, the team report how they spent 6,120 observation hours working across six research stations, recording orangutan kiss-squeaks from around 70 individuals.

There is no known exchange between the different communities and they are very far apart.

The team found high density communities of orangutans used a wide range of novel calls, but with a high turnover, many fell out of use. Small groups came up with new calls less often, but retained novel calls when they occurred.

The calls that were most immune to other possible influences were the alarm calls.

There is growing evidence that great ape repertoires, like human languages, are composed of calls which can be carefully controlled, and combined to make syllable-like combinations that can be used to communicate.

The new evidence shows that great apes are a good model species to improve our understanding of language origin and language.

The team says the new findings add weight to the idea that communication among our ape-like ancestors was influenced by social factors.

The new study highlighted the importance of conservativism.

If we are to have any chance of uncovering further pieces of the puzzle of language evolution, Great apes and their habitat must be preserved.