Why do adult male orangutans usually avoid one another?

Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

An illustration of a female Bornean orangutan (Pongo pygmaeus) with long reddish-brown fur, hanging from tree branches with one arm extended upward and one leg hooked over a branch. A scale bar at the bottom shows lengths of 30 centimeters and 12 inches for size reference. — orangutan Female orangutans (*Pongo*) have the longest breeding interval of any mammal, giving birth on average once every eight years.

Adult male orangutans are the most solitary members of their species, and their tendency to avoid one another is a fundamental aspect of their unique semisolitary social organization.1

This behavior serves to maintain social spacing within their environment. Adult males utilize a powerful vocalization known as the "long call"—a sequence of roars that can travel up to 2 km (1.2 miles)—to establish their presence and keep other males at a distance. By avoiding direct contact, they minimize the frequency of aggressive confrontations, which typically only occur when multiple males are drawn to a sexually receptive female. In such instances, the presence of a female can trigger intense competition and combat between males.1