Article curated by Ginny Smith
Animals certainly communicate- some using sounds, and others using body language, pheromones or even electricity. But does any of this actually constitute language?
The first step towards language is to associate sounds or signs with objects, and we know some wild animals can do this. Vervet monkeys, for instance, have a different call when warning of an eagle than a snake. But to constitute proper language, there also needs to be syntax or grammar. This set of rules allows words to be combined into an infinite number of meaningful phrases and sentences. This seems to be something unique to humans- no wild animals have yet been found to use grammar. But that doesn't mean they definitely don't- it could just be their form of language is so different from our own we aren't able to recognise it.
Bats are highly sociable animals, living in co-operative groups. This makes it likely they have complex methods of communication, but currently we know very little about how they talk to each other. Researchers know that they have hunting calls, often high frequency bursts that get higher as they get closer to the prey. But they also produce lower frequency calls, which scientist believe they use to talk to each other. However only around 5% of these calls have been classified, so there is still much to uncovered about the mysterious world of bat communication
Whale song is famous the world over for its haunting sound and ability to travel long distances. But we don't know for sure why they produce these incredible sounds. There are various hypotheses, the prevailing one being that it is for mating purposes, but it could be for more than that. Studies are now showing that baleen whales use the same songs when hunting and feeding, not just breeding. However they also use 'tick tock' noises, called paired bursts, to communicate deep underwater when hunting. The purpose of these sounds are not well understood, as it could be for luring out prey, working together to locate prey, or even as a dinner bell call for other whales nearby when prey is found. Why then, would they also sing when hunting? Is it for the same purpose, or another? Until we can speak 'whale', we may not find the answers to these questions.2
Fascinatingly, it has been found that in sperm whales' calls vary depending on the region a whale is from- they have the equivalent of accents or possibly even languages. Within a group, there is also a difference in how individuals 'pronounce' a call used by all whales, known as the "five regular". Researchers think this helps members of a group identify each other- a bit like a name.2
Reports on wild sharks have documented cooperative behaviour, play behaviour, and courtship behaviour. However, behavioural understanding of shark species is “alarmingly incomplete”, and most studies have taken place in captivity.
Whilst observed behaviours suggest that sharks can communicate, some doubt remains as we have never observed them emitting sound signals. Sharks have very good eyesight, so it could be they communicate via body movements instead. Researchers believe that shark body language can actually be used to interpret their moods and predict behaviours; over fifty distinct movement patterns have been isolated in shark behaviour.
A further possibility is pheromones. Although we are not sure whether sharks use pheromones, they are a well-known way of communicating throughout the animal kingdom. Sharks have a strong sense of smell and have been noticed responding to scent signals, such as being attracted or repulsed by the source of the smell, so it could be they use these chemical signals to communicate. It is even possible sharks may communicate on a cellular level by using their electroreceptors to sense the salt solution in each other’s cells. How they could intentionally send out signals like this is unclear though, so the secret nature of how sharks “talk” remains.
Many bees live in large and highly complex groups, so they need to communicate with each other- for example to explain where they have found a good food source. On way they do this is using the 'waggle dance'- an intricate and complicated set of movements which encode directions in a way we don't yet fully understand. Recent work on pheromones and smell discovered that four specific hydrocarbon molecules are released during waggle dancing and may help communicate the information via a chemical signal. When these chemicals were sprayed on a hive, foraging activity was seen to increase, supporting this idea.
This article was written by the Things We Don’t Know editorial team, with contributions from Ginny Smith, Rowena Fletcher-Wood, and Joshua Fleming.
why don’t all references have links?
Antunes, R., et al., (2011) Individually distinctive acoustic features in sperm whale codas Animal Behaviour 81.4:723-730 DOI: 10.1016/j.anbehav.2010.12.019
Stimpert, A., et al., (2012) Humpback Whale Song And Foraging Behavior On An Antarctic Feeding Ground Public Library of Science ONE 7.12 DOI: 10.1371/journal.pone.0051214
Parks, S., et al., (2014) Evidence For Acoustic Communication Among Bottom Foraging Humpback Whales Nature 4.7508 DOI: 10.1038/srep07508