Researchers who tracked the moans, cries, and laughter of two geographically separated populations found that vocal differences became more pronounced with age. Their findings challenge the long-held assumption that chimpanzee vocalizations are inflexible and determined solely by genetics.
Eastern chimpanzee (Pan Troglodytes Schweinfurti), a mother with her child in Gombe Stream National Park, Tanzania. Image credit: Ikiwaner.
“Dialects are a loud expression of demographic composition,” says a postdoctoral researcher at Queen Mary University of London. Cassandra Guiragossian And her colleagues.
“At early stages of human ontogeny, vocal behavior is relatively similar across populations from an acoustic perspective.”
“As ontogeny progresses, the differences between populations increase.”
“Research in recent decades has shown that chimpanzees exhibit population-specific vocal characteristics, but the cause of this variation – whether it is due to social, genetic, or ecological factors – continues to be debated.”
In this study, Giragossian and co-authors compared the vocalizations of infants and boys. eastern chimpanzee (Pan Troglodytes Schweinfurti) They originate from two geographically separated populations.
One population was from Chinfunsi Wildlife Orphanage in Zambia and the other from Gombe National Park in Tanzania.
By analyzing grunts, cries, and laughter, the researchers found that differences between groups became more pronounced as the animals grew older, suggesting that vocal behaviors continue to develop throughout childhood.
Similar to people recognizing different regional accents, young chimpanzees from different communities were found to produce subtly different speech patterns.
Moreover, some group-specific vocal features were already present in infancy, whereas others emerged in early childhood.
This developmental pattern suggests that social interactions, environmental conditions, and other non-genetic influences may all contribute to shaping how young chimpanzees communicate.
This finding provides the first evidence that group-specific vocal differences become increasingly distinct during chimpanzee development.
By focusing on how communication changes over time, rather than simply comparing adults from different populations, this study provides a new perspective on the processes that shape vocal behavior in other species.
“Understanding how communication develops during early childhood is fundamental to understanding animal behavior,” Giragossian says.
“Our findings demonstrate that chimpanzee vocalizations are not only fixed from birth, but continue to develop as young animals interact with their social and ecological environments.”
“This study contributes to the growing body of evidence that primate communication is more flexible and dynamic than previously recognized.”
“By examining vocal development through an ontogenetic lens, this study provides a valuable framework for investigating how communication systems emerge and diversify within animal populations.”
“While this study does not suggest that chimpanzees have a language or human-like speech abilities (e.g., processes involving agreed grammar and vocabulary), it convincingly shows that chimpanzee vocal development is influenced by more than just genetics.”
“By showing that population-specific vocal patterns emerge and become more pronounced during development, this study provides new insights into the biological and environmental factors that shape primate communication and provides a new perspective on the evolution of complex communication systems.”
of study Published in an online journal PLoS ONE.
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K. Giragossian others. 2026. Ontogeny of dialects in chimpanzee vocalizations. PLoS One 21 (9): e0355313;doi: 10.1371/journal.pone.0355313
Source: www.sci.news
