Vocal Learning In Elephants
Vocal learning is the ability to learn and produce new vocalizations and modify existing ones following exposure to new auditory signals¹. This ability is very important for animals who live in groups that constantly split up and merge since it allows individuals to maintain close relationships despite having reduced (or no) contact for long periods of time. Vocal learning helps them recognize each other when they reunite after separation by making their calls more similar and therefore solidifies relationships². Elephants are one such animal and this faculty, which is foundational for spoken language³, has been found in both the African and Asian species.
The first discovery of vocal learning in elephants was described by Joyce Poole and her team in 2005⁴. In Tsavo, Kenya the researchers studied an adolescent female elephant named Mlaika who lived in a group with other orphaned elephants. Her night quarters were near a highway and she was documented emitting noises similar to those given off by passing trucks. She would do this for a few hours after sunset which is the best time for transmitting such low frequency sounds in the African savannah. In order to test whether her vocalizations were actually imitations of the truck noises the researchers made recordings of the two and compared them. Her calls were found to differ significantly from natural elephant calls but not from the truck noises⁴. Interestingly they also found that her calls were not more similar to the truck noises if they were recorded at the same than if they were recorded separately⁴.
At the Basel Zoo the researchers worked with a male African elephant named Calimro who had lived with two female Asian elephants for 18 years⁴. He was documented making clicking noises that are commonly given off by Asian elephants but are not naturally part of the African elephant repertoire. To test whether this was vocal learning the researchers compared his clicking noises with those of Asian elephants and a variety of African elephant vocalizations. Calimro’s clicking noises were found to differ considerably from the African elephant calls but not from those of Asian elephants³. He had therefore learned an entirely new auditory signal based on input from the animals around him.
Another fascinating study on vocal learning was done by Angela Stoeger and her colleagues at the Everland Zoo in South Korea with an Asian elephant named Koshik who reportedly could pronounce six Korean words by imitating his keepers’ speech⁵. Although elephant vocal tracts are usually unable to produce such high frequency sounds Koshick would modify his by placing the tip of his trunk in his mouth and then raising his lower jaw. In order to test whether his utterances were actually imitations the researchers made recordings of them and asked Korean native speakers to transcribe them. They found that there was much stronger agreement for vowels than consonants. There were also exact spelling matches for the word “hello” and “considerable” agreement for three more (“no,” “lie down,” “sit down”)⁵. The researchers deduced that he was in fact engaging in vocal learning.
Vocal learning is the ability of an animal to produce new auditory signals following input from its environment. It has been documented in elephants when they imitate artificial noises, the vocalizations of other species, and even words. However, this field of animal cognition science is still in its infancy and its very likely that much more evidence for vocal learning in elephants will be uncovered in the near future.
References:
¹Janik, Vincent M., and Peter JB Slater. “Vocal learning in mammals.” Advances in the Study of Behaviour 26 (1997): 59–100.
²De Waal, Frans BM, and Peter L. Tyack, eds. Animal social complexity: intelligence, culture, and individualized societies. Harvard University Press, 2009.
³Hauser, Marc D., Noam Chomsky, and W. Tecumseh Fitch. “The faculty of language: what is it, who has it, and how did it evolve?.” science 298, no. 5598 (2002): 1569–1579.
⁴Poole, Joyce H., Peter L. Tyack, Angela S. Stoeger-Horwath, and Stephanie Watwood. “Animal behaviour: elephants are capable of vocal learning.” Nature 434, no. 7032 (2005): 455–456.
⁵Stoeger, Angela S., Daniel Mietchen, Sukhun Oh, Shermin de Silva, Christian T. Herbst, Soowhan Kwon, and W. Tecumseh Fitch. “An Asian elephant imitates human speech.” Current Biology 22, no. 22 (2012): 2144–2148.
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