We don't know what "language" is. This is an attempt to empirically construct that definition from the bottom up. Calling it "language" may saddle whatever's going on here with needless or even misleading assumptions.
By the broadest definitions, chimpanzees have a language, and maybe even multiple dialects. By the narrowest definitions, only humans have languages.
People behave like there's some profound truth here, but this is really just semantics. I don't see why it's such a touchy subject, other than the fact that people like to believe humans are a special case.
On the other hand, I feel it is highly likely that other, now extinct, homo species had human-like language skills. Language evolved, and it is not very plausible that it did so in one leap from that which we see in other species today. Some level of language and other cognitive skills are to be expected in other species, and the study of those skills is both worthwhile in itself and as a guide to better understanding ourselves.
Who is to say it is not?
By analogy, if you are laying under your vehicle, loosening a bolt with a wrench, and your dog is hunched nearby watching, he can clearly see what you are doing (and quite possibly understands that the wrench is needed to loosen the bolt) but he cannot understand why you are doing that, or what 19mm means, nor express either. The dog understands leverage in terms of his world, but quite possibly not that the wrench is used to create it in a different way. Certainly he couldn't explain it to another dog.
The other apes are doing things we can see and hear, but do not understand or put any importance on. One thing I note is that there is no mention of body language in that essay. Posture and gesture (and situation) add a huge amount of complexity to language.
And apes are surely using that too.
For example, I can tell you "no" but with minimal deft gestures, convey understanding in you that I mean "maybe" or even outright "yes". The canonical example being Linus Torvalds saying "No" to whether he was asked¹ to add back doors to the Linux Kernel, while indicating non verbally and quite clearly that he meant yes.
You and I have "that knowledge" to understand the whole message, while we quite likely lack nuance that other apes have in their communications.
¹and we both understand "asked" to actually mean "pressured" to some degree, and told not to tell. And there was more than duality in Linus' answer, he was also saying "Don't trust me to not fall to pressure" and "If I am pressured, they shouldn't trust me to keep it a secret".
Apes are surprising in their sophistication.
Compare to parrot and corvids. Birds have evolved a brain more efficient than humans. Crows are able to work with abstractions, and pound-for-pound use less brain matter.
And then there's the octopus and other cephelopods.
And it's not like both of these sides don't have an almost endless variety of languages...
For human language models there are obvious practical uses and we can intuitively evaluate the quality of the models. For animal communication you need to use other biological variables, like valence in the pig communication example.
I do remember one where they generated artificial frog mating calls and were able to generate artificial ones that were exceptionally attractive to female frogs, but that was from a while back, and I can’t find the link.
https://medium.com/health-and-biological-research-news/prair...
https://www.npr.org/2011/01/20/132650631/new-language-discov...
Original paper: sciencedirect.com/science/article/abs/pii/S0003347205801174?via%3Dihub
edit: I think this is the one I was thinking of: https://news.ycombinator.com/item?id=26874309
What would be possible in a thoroughly surveilled group is to do a detailed analysis and record of the behavior and interactions and dialogues etc., possibly even eye gaze direction, and it's exact timing, and then create some type of AI model based on all of that together.
If this same analysis were conducted with other populations of chimpanzees as well, could it be determined whether different populations use different languages? I believe this sort of thing has been tried with Orcas, with the conclusion that different populations have different languages.
I have no doubt they have a language with each other, we're just not smart enough to figure it out yet.
