Vocalisation techniques across different animal groups and the ways they communicate with one another
Can animals speak?
Linguistic intelligence is the ability to understand and generate language. Among animal species, parrots are famously strong in this area. Parrots have been taught to use thousands of human words, and even colors and numbers.
Meanwhile, a number of primates have been taught to use human sign language. Koko the gorilla learned to make a thousand different signs. She had conversations with her keepers, and was even capable of telling lies.
Koko had a pet kitten, which she named All Ball. Once, in a moment of anger, Koko ripped a sink off the wall of her enclosure. When a keeper arrived, Koko used sign language to blame the damage on All Ball.
Interestingly, no animal has ever used human language to ask a question. Scientists are uncertain why this is.
Generation vs. comprehension
Talking parrots and signing primates are both examples of speech generation, but that is not the only sign of linguistic intelligence. Speech comprehension is also important: hearing language and understanding what it means.
Studies have shown that dogs can learn up to 250 human words. Most dog-owners have probably noticed this – when a dog hears the word ‘walk’, they instantly get excited.
A dog cannot generate any human language back at us. They lack the vocal range of a parrot, and have no hands to use for signing. But despite these physiological limitations, the ability to comprehend our words is a sign of linguistic intelligence.
Interspecific vs. intraspecific
When animals interact with human language, scientists call it interspecific communication – language used between two different species. Traditionally, this was always used as a measure of an animal’s linguistic intelligence.
But is this a fair approach to take? Animals did not evolve to speak to humans; they evolved to speak to other members of their own species. We would never judge a human’s language skills on their ability to squeak or squawk, so we should not judge an animal’s language on its ability to speak like us.
In the last few years, scientists have moved away from interspecific communication, and started to focus on intraspecific communication instead. This is seen as a more valid measure of a species’ linguistic intelligence.
Language in primates
When it comes to intraspecific language, primates are fairly competent. Chimpanzees use vocalizations such as grunts and barks to express emotions and communicate danger.
But their main form of language is physical gestures. A recent study found that chimps used 31 hand gestures, and 18 facial gestures, to talk to each other in captivity. Another study found evidence of turn-taking – chimps let each other speak turn by turn, just as humans do when having a conversation.
This is probably why primates like Koko the gorilla were able to learn human sign language. They had already evolved a gesture-based form of communication, so signing was compatible with their innate linguistic intelligence.
Language in birds
Birds are capable of producing complex vocalizations, but whether birdsong counts as a type of language is subject to scholarly debate. Language, as a concept, is hard to define, but it is broadly seen as a way to communicate information using some kind of vocabulary and grammar.
Birdsong communicates information: they use it to warn each other about approaching predators. It also seems to have a vocabulary: different predators are described using different calls. In some cases, there may also be grammar: chickadees change the number of ‘dees’ in their distinctive call to indicate the size of an approaching threat.
The way parrots are able to learn human language suggests birdsong follows similar linguistic forms. It seems unlikely that a bird could learn to speak English if it had not already evolved a brain with similar systems of its own.
Language in cetaceans
Cetaceans, such as whales and dolphins, communicate using streams of clicks which scientists refer to as codas. Dolphins appear to form sentences, and may refer to one another using signature whistles, almost like having names.
Pods of whales, within the same species, have been found to speak different dialects. These dialects seem to be a product of cultural learning, as words and phrases are passed down through generations.
When it comes to linguistic intelligence, these examples suggest that cetaceans are very advanced. And scientists are now attempting to translate their languages into English. Project CETI (Cetacean Translation Initiative) is an ambitious project which hopes to use artificial intelligence to translate whalesong into a human language.
It would be one of the biggest breakthroughs in scientific history. Instead of teaching an animal to speak our language, we could communicate using one of theirs.
Eusocial insects
An unusual form of animal language can be found in eusocial insects. These insects, including species of bees and ants, live in a tight-knit colony, where communication is essential.
Some bees communicate using ‘waggle dances’, where they move their bodies in different rhythms to tell other members of the colony that a predator is coming, or where to find some nearby food.
Other eusocial insects communicate using chemical signals, which can be passed from one individual to the next in a rapid chain of information. This has been compared to the way that cells communicate in a multicellular brain; in other words, the colony could be seen as a single, collective intelligence.
It is debatable whether this counts as language, but it is certainly a form of communication, and one which evolved extremely differently to our own.
