How the Male Monkey's Nasal Size Dictates Social Status

The proboscis monkey, native to the island of Borneo, possesses one of the animal kingdom's most distinctive and remarkable physical features: the enormous, pendulous nose of the adult male. This feature develops progressively as the male matures, transforming from a relatively standard primate nose into a large, fleshy, and highly noticeable organ that can hang down past the animal's chin. This pronounced sexual dimorphism ensures that the male's appearance is dramatically different from that of the female, which retains a smaller, upturned, and slightly more modest nose throughout her life, setting the two genders clearly apart within the social structure.