How do male chimps ask for sex? It depends on their local dialect

Male chimpanzees have a unique way of asking for sex that varies depending on their local dialect, according to a recent study conducted by Catherine Crockford of the Max Planck Institute for Evolutionary Anthropology. In an interview with As It Happens host Nil Köksal, Crockford explained that subordinate male chimps use covert physical gestures, which she calls “the sneakies,” to solicit sex without attracting the attention of the alpha male.

The study, published in the journal Current Biology, focused on the mating signals of chimpanzees at the Taï National Park in Ivory Coast. Researchers observed four distinct ways that male chimps signaled their desire for sex: knocking their knuckles on a hard surface, kicking their heels, tearing strips from a leaf, and waving a branch. Interestingly, these mating moves varied between different chimpanzee communities within the park, suggesting that chimp populations have their own unique dialects.

For example, while all four groups of chimps in the park performed the branch and heel gestures, only the northeastern chimps knuckle-knocked, and only the southeastern chimps used leaves. This difference in behavior was surprising, considering that the two populations share a gene pool and live just 500 kilometers apart in the same habitat. Crockford explained that the young males must learn these gestures by watching the older males, highlighting the cultural transmission of behaviors within chimpanzee communities.

Julie Teichroeb, a primate behavior researcher at the University of Toronto Scarborough, noted that differences in communication have been observed in many animal species, including whales, songbirds, and elephants. She emphasized that culture is a fragile aspect of animal behavior that can be lost over time. Crockford shared a poignant example from the Taï National Park study, where the knuckle-knocking gesture among northern chimps declined in prevalence due to disease outbreaks and poaching, ultimately disappearing from that group.

The loss of cultural behaviors like the knuckle-knocking gesture among chimpanzees serves as a reminder of the fragility of animal culture, similar to human culture. Crockford expressed concern about the impact of poaching on chimpanzee populations, noting that the loss of cultural practices could ultimately affect their survival. Teichroeb echoed this sentiment, highlighting the importance of preserving animal culture to safeguard the diversity of behaviors within chimpanzee populations.

Overall, the study sheds light on the intricate social dynamics and cultural diversity among chimpanzee communities, emphasizing the need for conservation efforts to protect not only the animals themselves but also their unique cultural practices. By understanding and preserving these behaviors, researchers can contribute to the long-term survival and well-being of chimpanzee populations in the wild.