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When do male orangutans become aggressive toward other males?

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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.

Male orangutans typically exhibit aggressive behavior toward other males when a sexually receptive female is present. In these instances, combat between males may occur as they compete for mating opportunities.1

Orangutans generally maintain a semisolitary social organization and are usually silent, preferring to avoid one another. While adult males are the most solitary members of the species, they will associate with females during consortships, which typically last 3 to 10 days and correlate with the female's ovulation.1