Anthropologist at Georgia University Robert Salmi conducted a series of experiments with gorillas from the state zoo. His caretakers found that a 24-year-old female named Sukari meets people with a strange sound, which had never heard from gorillas before. It can be described as a mixture of sneezing and coughing, and it sounds like “SNADA” or “SNOF”.
The caretakers drew attention to the fact that the bitch makes this sound only in the presence of a person, but not in communication with other gorillas. Salmi recreated several situations with the presence of food and caretaker in the field of view of the gorilla, but in different reach. .
Further observations showed that soon all the gorillas in this zoo mastered a new cry. Salmi also received reports that six more individuals from other zoos that were not familiar with the bucket also used a similar sound to attract people’s attention. Acoustic analysis showed that this sound was invented by the gorillas themselves, they did not imitate the previously heard signal. It turns out that the gorillas learned to invent new sounds specifically for contact with people.
Source — PLOS ONE