Zoo Gorillas Invented Unique New Sounds to Alert Zookeepers Who Feed Them

There is no doubt that many animals have their own distinct languages, and some of the more advanced forms are found in communities of non-human primates like Gorillas, Chimpanzees, and Orangutans.
gorillas

Chimpanzees can make specialized calls to unite their hunter mates and pursue smaller monkeys for a protein-rich meal.

Non-human primates among them gorillas have been known to employ vocal communication, and scientists are vigorously working to comprehend the meanings and applications of these calls.

Of course, when animals begin creating new vocals that can be interpreted as never before heard words, the task gets more challenging.

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Creating new vocals

The ability to create new vocalizations to attract human attention has only been documented in two other species: Zoo-housed orangutans and chimpanzees. And now, we can add gorillas to that list.

Bornean orangutan Pongo pygmaeus Tanjung Putting National Park 15
Bornean orangutan (Pongo pygmaeus) by Thomas Fuhrmann under CC BY-SA 4.0

A wonderfully weird discovery was made by University of Georgia and Zoo Atlanta scientists when they noticed their western lowland gorillas had come up with a way to get the attention of their zoo keepers. 

The gorillas have been able to summon their zookeepers with the noise, described by zookeepers as a peculiar “cough-sneeze” hybrid.

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A 24-year-old female gorilla, Sukari, demonstrates this strange sound equivalent to a human ‘ahem,’ which researchers have called a ‘snough.’

Koko the Gorilla

Many people are aware that Koko’s amazing capacity to use sign language to interact with humans in the 1980s and 1990s brought attention to gorilla intelligence.

She was trained and worked diligently at it, but it appears that gorillas have taken it upon themselves to develop special forms of contact with humanity on their own terms.

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How did the zookeepers know that the noise was made on purpose?

Roberta Salmi, a biological anthropologist and researcher from the University of Georgia, and her colleagues conducted an experiment to confirm the purpose of the ‘snough.’ They placed eight of the zoo’s gorillas in three different situations.

Zoo Atlanta Gorilla 8 1
Zoo Atlanta Gorilla 8 by Tim under CC BY 2.0

In the first case, there was only the keeper. On the second occasion, only the meal was present. The keeper was holding the food in the last one. When the food and the keeper were present, they were only in sight but out of reach.

The researchers observed that the gorillas involved would use the ‘ahem-like’ vocalization most frequently when there was a human presence with the food. This indicated that it was intentional to garner human attention to get the food.

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Similar ‘ahem-like’ sounds have also been found in other US zoos too.

According to reports, up to 33 gorillas held in 11 different zoos across the US and Canada make a similar sound. However, only six gorillas at four different facilities have been documented to have used the sound thus far.

Salmi and his team are unsure whether different groups have worked to check if the sound is effective or if the sound has spread across the entire clever primates – teaching each other what they have discovered.

Most language components, such as syntax, vocal learning, and semantics, do appear in other creatures’ communication systems.

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It was originally believed that non-human primates lacked the tools necessary to vocalize in the same manner as humans. But this has since been disproved.

Our vocal muscles and evolutionary history are comparable. Gorillas have been labeled as “non-vocal” learners for whatever prevents them from sophisticated vocal mimicking.

The ‘snough’ call was reserved for human

The use of “snough” by the gorillas to communicate with one another has never been observed. The originality of this call adds to a growing corpus of research showing that primates are vocal learners and may create new sounds for various situations.

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The authors stated in their paper that caged apes have “scarce but progressively growing evidence of vocal learning and/or innovation.”

Chimpanzees acquire new referential food calls through vocal convergence under social integration. Orangutans can learn to generate voiced utterances and whistles. Enculturated apes, like the chimpanzee Vicky and the gorilla Koko, can produce a small number of innovative utterances.

Earlier studies have shown that gorillas can recognize and distinguish between the sounds of several humans.

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How popular is vocal learning

Only a few species of birds, bats, pinnipeds, cetaceans, and elephants have been confirmed to have the unusual ability to generate distinctive calls in the animal kingdom. But they all do via imitation.

Pinniped collage
Pinnipeds by Bobisbob under CC BY-SA 3.0

Although these cheeky primates are clearly capable of imitating us in various ways, the acoustic study revealed that the gorilla’s ‘snough’ is a unique sound and not a mimic.

“These reports confirm that gorillas may generate their calls and signals deliberately to modify the attention state of their keeper,” the scientists noted in their research. They also show that gorillas can adjust their sounds to produce a novel sound.”

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Researchers’ will continue to study gorillas

Future research, according to the researchers, should aim to better understand the degree and modes of “snough” transmission across captive populations.

By contrasting it with the whole vocal repertoire of the zoo gorillas, we can determine if it is an existing call type or a modulated variation employed in a fresh setting.

The researchers could not conclude how the sound emerged in the gorillas, whether randomly or learned by observing humans.

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However, they speculate the cough-like sound attracted the attention of the keepers because they are monitoring their health, and the primates could have noted this trend.