If animals could talk... or can they? Behind some of our world creature's gestures or sounds is more than we thought so far. With new ideas scientist are trying to decipher the communication of animals.
The parrot Polynesia taught the English doctor Dr. John Dolittle in the 1920's to chat with apes, dogs, pigs and birds. 50 years later the natural history professor Habakuk Tibatong succeeded in another coup - with his help the Urmel and a handful of other animals learned the human language.
Although, the two linguists and their animal companions owed their linguistic talent to the blossoming imagination of children's book authors Hugh Lofting and Max Kruse, reality is now catching up in big steps. The human language ability in all its diversity and complexity is still regarded as unrivalled and as a characteristic of being human par excellence. But how close animals can come to speaking has long been the subject of heated debates.
Training in sign language
Answers are obviously often looked for with our closest relatives, the great apes. The chimpanzee Washoe, for example, who lived from 1965 to 2007, learned 350 words of American sign language thanks to lessons with her trainer Roger Fouts and used them creatively to exchange information with humans and chimpanzees. She even taught her foster son Loulis some gestures. Koko, a gorilla lady born in 1971, even gestures over 1000 words and understands over 2000 spoken English terms, according to her trainer, but she can only arrange her vocabulary syntactically to a limited extent. Bonobo Kanzi, who was born in 1980, is said to have taught himself a few gestures when he watched videos of Koko and, according to his trainers, otherwise communicates virtuously using a keyboard with lexigrams depicting certain objects or ideas.
Other researchers express great doubts about the linguistic performance of primates, accuse their trainers of wishful thinking and overinterpretation, and point to the clear limitations of animal linguistic talents. For example, Washoe, Koko, Kanzi and Co. have never learned to ask questions.
Alex, the talking grey parrot
Our next cousins were beaten in this matter by a particularly prominent animal language talent, which does not even belong to the mammals. Alex the Grey Parrot, who died in 2007, was not only able to parrot over 100 English words, but also to use them semantically and syntactically reliably to distinguish, for example, wooden blocks, balls or keys according to color, material and even quantity. And according to the reports of his coaches, he even asked an existential question - which color he has.
Whether the impressive use of individual language elements by these intensively trained individuals suggests that animals can learn to speak real language remains controversial. Even the scientists directly involved in the research are rather cautious.
Nevertheless, the list of findings on complex communicating animals is getting longer - and not only of those in captivity. Thanks to a long-term study with wild chimpanzees in Africa, we now know that even without human training the animals use a diverse repertoire of at least 66 gestures. Another team of researchers pestered wild chimpanzees with a stuffed python hanging from a fishing line until they succeeded in proving that although the animals' alarm calls are simple grunts in themselves, they are used by the animals, like gestures, for highly nuanced and context-dependent communication.
A fine ear for gibbon singing
Another study caused a big surprise: A tiger skin that researchers draped over either a scaffold or a crawling student - to depict a "sitting tiger" or a "moving tiger" - elicited unexpected nuances in Gibbons' singing. But only thanks to the extremely fine hearing of zoologist Angela Dassow from the University of Wisconsin Madison, who listened to the sound recordings of her colleague Esther Clarke for one and a half years. She had followed 13 gibbon groups through the jungle in Thailand and confronted them with models of snakes, birds of prey, leopards and tigers.
Clarke had already identified seven different sound units in her study, which the gibbons combined similar to phonemes of human language depending on the situation, for example to warn of the different predators. But after Dassow had heard herself through the data set, she realized that this was by no means all: "In fact, the gibbons use 28 different sound units, and they compose them in many different ways. The sound sequence with which they sing about a sitting tiger sounds different than the one for a moving tiger," she explains.
Although Dassow wouldn't say that Gibbons can really speak, she believes that the newly discovered vocal nuances clearly share some elements of language: "The acoustic units are flexibly assembled with reference to the environment," she says.
Your study was quickly taken up by many media. The study has not yet been published in a specialist journal that calls for a peer review - in other words, a critical examination by uninvolved experts of the structure, method and outcome of the work. Accordingly, these results are to be regarded as preliminary.
Angela Dassow doesn't challenge that. Together with her doctoral supervisor, the computer scientist Michael Coen, she has developed an algorithm that, according to her data, is able to distinguish between gibbon sounds just as well as her own hearing, but which is much faster. It is not without reason that Dassow and Coen gave their project the working title "Dr Dolittle".
Animal fullness of sound
According to the researchers, the first results are promising: The communicative repertoire of rats, for example, has already increased from three to 29 calls, according to a first test run by Dassow. According to other studies, dolphins master 168 sounds, and elephants also communicate with a complex fullness of sound, most of which takes place in the infrasound range, which is inaudible to humans. But here, too, critics raise questions: Are such audio samples characteristic of the natural communication of the respective species - and can generally valid conclusions actually be derived from them?
One thing is clear: the studies are still in their first stages. In view of new technologies, many researchers are currently testing a wide variety of recording methods and algorithms. But it also seems certain: If you listen carefully, you will discover nuances that were previously unknown. The question is how to interpret them.
It gets even more complex with animals that don't use their voice as much: Here, researchers are investigating their body language - for example by recording the movement patterns of lizards and having them replayed by "spying" animal robots or video projections in communication experiments. In this way, the scientists want to understand the meaning of the movements.
The better we understand the patterns, dynamics and limits of animal communication, the easier it may be to solve the riddle of how humans learned to speak. It could have been an increasing differentiation of simple utterances, which were gradually enriched with semantic meaning and later supplemented by syntactic innovations (lexical model). But in the beginning, instead of the spoken word, there could have been sign language, as the pantomimic talent of our closest relatives suggests (gesticular model) - or a combination of both, as in the case of wild chimpanzees.
A third approach, which already convinced Charles Darwin, sees the origins of the language in mating or territory songs, as one knows them today from birds. Music conveys above all emotions that people can recognize regardless of their cultural background, and hardly any semantic content or syntax. But when dolphin whistles, elephant infrasound and gibbon songs increasingly reveal complex communicative nuances, even the idea that the music of primitive man might have laid the foundation for language does not seem absurd.
About the author
Dr. Nora Schultz - Diploma in Journalism, B.A. Biological Sciences, PhD - Biology and Communication are my two big interests; in the brain both come together.
This article has originally been published on www.dasgehirn.info.