Sperm whales appear to communicate with a series of clicks
Amanda Cotton
Sperm whale calls are much more complex than we think and may be the closest animal communication system to human language ever discovered.
This claim is based on an analysis of thousands of interactions between sperm whales in the Eastern Caribbean (physeter macrocephalus), recorded over several years.
“It's really amazing that another species on this planet could have the ability to communicate,” he says. Daniella Russ at the Massachusetts Institute of Technology. “We used to believe that we were the only ones.”
Sperm whales are long-lived animals with complex social lives, with females and their young living in small groups. They hunt prey (mainly squid) using echolocation with a regular stream of clicks. Whales were well known to vocalize to each other in short bursts of irregular click patterns lasting several seconds, but their meaning was unknown.
“They dive together, eat together, and hunt together,” Russ says. “There's so much collaboration going on and we're listening to them while they're doing all these activities. So the question is, what does all this mean? .”
For the study, Russ and her team recorded around 9,000 sperm whale calls using a device attached to the animal with a suction cup as part of a monitoring project conducted from 2014 to 2018. was analyzed.
It was previously thought that this group of whales used 21 different click patterns known as codas. In the latest analysis, the team discovered that there are actually 18 different basic coders, but they can be modified to give several more levels of complexity.
For example, known coders may be tagged with an extra click at the beginning or end. This often signaled that it was the listening whale's turn to speak.
Another finding is that known codas can be stretched by slowing down while maintaining the rhythmic pattern.
Based on these findings, the researchers estimate that there are hundreds of possible click patterns, although they only saw 156 in this dataset. They created a “phonetic alphabet” for sperm whales that will help classify future recordings.
Just as human languages combine different letters to form words, whales appear to add complexity by combining different codas in succession.
“Once you get this combinatorial basis, you can get a finite set of symbols. [and] It composes them to create an infinite number of symbols according to a set of rules.” Pratyusha Sharma, also available at MIT. “Now that we have this alphabet, the next thing we're going to do is see how they line up.”
paul white Professors at the University of Southampton in the UK who were not involved in the study say the fact that sperm whales use these sounds for echolocation while hunting means they can accurately detect small changes in the interval between clicks. He said that it suggests. “There is logic in assuming that these intervals may convey information.”
“It's always been a mystery how sperm whales, which have such complex social structures, communicate with each other when the signal is a boring set of pulses,” he says. “The idea that fine-grained structures within the coda convey information is an interesting concept.”
If it can be shown that combinations of clicks do indeed convey a wide range of meanings, the sperm whale's ability to communicate would be unique among non-human animals.
Several other species, including various primates, can signal each other with small calls and movements. For example, some monkeys use different alarm sounds to warn each other about different predators, such as leopards, snakes, and eagles, and these predators require different escape strategies.
However, these communication systems are too limited to be classified as language, which is usually defined as the free expression of thoughts as signals.
topic:
Source: www.newscientist.com
