Chimpanzees hoot, pant, scream, and bark! Sometimes they chain these sounds together. But do these combinations mean anything? In 2019 and 2020, biologist Tatiana Bortolato visited the rainforests of Côte d’Ivoire (also known as Ivory Coast) in West Africa to find out.

She recorded over 900 hours of chimp calls. Later, Bortolato and other scientists analyzed the calls. They noticed chimps often repeated sequences of sounds the same way humans repeat words. They found 390 of these word-like sound patterns. Most included two or three sounds, but some were longer.

Now the team wants to find out if the call patterns have meaning. Chimps are primates just like humans. Understanding how chimps communicate could reveal how early humans learned to talk, explains Cédric Girard-Buttoz, a biologist who led the study.