Male chimpanzees in Côte d’Ivoire’s Taï National Park use distinct “auditory gestures” to attract females. However, researchers have found that when the males die, these behaviors can disappear with them. The solicitation gestures used by these male western chimpanzees (Pan troglodytes verus) include tapping their heels or knuckles against fallen branches or tree trunks, shaking branches or saplings, or noisily tearing leaves off stems. In one of the four chimpanzee communities monitored for the past 45 years by the Taï Chimpanzee Project, a research and conservation group, the “knuckle-knock” was the main solicitation gesture used by males since 1991. But severe hunting pressure drastically reduced the chimpanzee population in Taï, from around 3,000 in the early 1980s to just 300 by 2010. The part of the Taï forest occupied by the northern community and their knuckle-knocking males was particularly vulnerable due to its proximity to villages, providing easy access to hunters. In 2008, the group’s last adult male, known to researchers as Nino, was killed for his meat. In the aftermath, a female took over as leader, and while the group continued functioning as a unit, the absence of multiple adult males meant there were no individuals left to perform and reinforce the knuckle-knock gesture. Today, even though young males have since grown up and assumed leadership, the behavior has not reemerged. Instead, it has been replaced by another gesture: the “heel-kick.” Porthos is one of the adult males now present in the North community. He is the son of…This article was originally published on Mongabay
The post When a chimp community lost its males, it also lost part of its love language first appeared on EnviroLink Network.