Orangutans make unique noises in big groups

How we speak is very much governed by the environment we grow up in. From accent, to slang, to language; our “group” shapes our communication style. And, after analysing years worth of audio recordings, it has now been found that social groups also influence the vocalisations of orangutans, with more original shouts happening in larger buffooneries. Julia Ravey spoke to lead author Adriano Lameira...

Adriano - As humans, we like to reserve our position in a special place among nature. Originally we were the 'tool user' or the 'tool maker' and now there are books with thousands of examples of tool use, like octopuses use tools and ants use tools. Then we moved on, 'okay, we're not the tool user, but we are the only cultural animal'. Turns out that that's also not the case. We're eating away how special we are and somehow language is our last reserved stronghold. The prevalent theory when we started was that unlike human verbal behaviour great ape vocal behaviour is innate, it's instinctive, it's automatic, it's reflexive, individuals have no control whatsoever, It just comes by instinct.

Julia - When did you actually notice orangutan noises were different across groups in the wild?

Adriano - That was right from the start. We started cataloguing the call repertoire of orangutans at one population and there were other populations relatively nearby. It was rather striking when, in one population, some orangutans would be doing certain types of noises when they are building nests. Then you go to a nearby population and they aren't doing those sounds, and then you visit another one and they do different sounds. We just had to start collecting the data and the evidence. That started almost 20 years ago.

Julia - What did you find when looking at orangutan vocal calls across these different groups?

Adriano - What we found was that there is a social influence. Each individual is being moulded by what he's hearing and who he's interacting with. We found that in high density populations, where there are many individuals living one with the other, that they really like to constantly produce novel calls. They'll do calls that were never heard before. But they'll do that once and then no one will adopt that new call because everyone is doing their style of things, so to speak. This turns out to be very distinct of what's happening in low density populations, where individuals encounter each other less often. What we see here is that when they communicate, they tend to go back to the same repertoire. In this sense, they can be thought of as more conventional, more conservative. What is interesting is that in the low density populations, although they are conservative and always go back to the same set of calls, where there is a novel signal, they do pick up that new signal and incorporate it into their repertoire, so their repertoires are more complex than the ones in high density populations.

Julia - Why do you think there is this disparity between the size of the populations and the number of original vocal calls? To me, it makes me think of a big city like London, where there's lots and lots of individuals, but they all live in their own little pockets. Is it like people are trying to stand out more?

Adriano - I think the parallel is a legitimate one. Once we start thinking that language is a continuous process and there are things that we share with great apes, when we start looking at the data, new parallels and similarities will show up. Maybe when we go to a big city or we live in a big city and when we dress in a quirky way, or we try to put our hair in a way that stands out, we may think that we are practicing our individuality and our free will and that those things are very human specific. Well now having similar data in evidence for our great apes, either that makes them more human or us more apes. In this way, I do hope that connecting us with our own larger setting will make us be more respectful and good stewards of the planet.

Julia - Yeah, I really love that. Seeing ourselves as an extension of other animals out there should hopefully enable us to be better at protecting the planet and these animals and their habitats.

Adriano - Yeah, exactly the same way as you respect a fellow human, you should adjust your respect to that animal.