Deep in the jungle, a whoop of excitement breaks out. It is quickly joined by a dozen additional voices and grows in volume, tempo, and tone to a frenzied screeching crescendo. It is the well-known “pant-hoot” call, a bonding ritual that enables the participants to recognize one another using their distinctive vocal tics. Walking through the ancient woodlands of Gombe Stream causes the human listener to experience a spine-tingling eruption that also serves as a warning of an impending visual encounter with man’s closest living relative, the chimpanzee.

The smallest of Tanzania’s national parks, Gombe is a precarious chimpanzee habitat strip that spans the rocky northern shore of Lake Tanganyika and the deep river valleys that surround it. The chimpanzees there are accustomed to human visits thanks to the groundbreaking work of Jane Goodall, who established the world’s longest-running behavioral research program in 1960. The matriarch of the original community, Fifi, who is the only surviving member and was only three years old when Goodall first set foot in Gombe, is still frequently viewed by tourists.

Since chimpanzees and humans share 98% of the same genes, it is not necessary to be a scientist to distinguish between the distinctive repertoires of pants, hoots and screams that characterize the celebrities, the power brokers, and the supporting cast. When you gaze into a chimpanzee’s eyes and they glance back at you, perhaps you will notice a spark of comprehension – a look of apparent recognition across the thinnest of species borders.