This prominent nasal structure plays a vital role in the complex social dynamics of the proboscis monkey groups, particularly those centered around one dominant male and his associated female harem. The sheer size of the nose is directly correlated with a male's dominance and social standing within the troop, serving as a powerful visual signal to both potential rivals and group members. It acts as an advertisement of the male's physical fitness and age, essentially a badge of honor that broadcasts his suitability to maintain leadership and control over the resources and individuals within his social unit, establishing a clear hierarchy.
