Black-and-white Colobus

Black-and-white colobus males produce loud roaring calls that serve both anti-predator and territorial functions. Roars given to predators warn group members; roars given at dawn establish territorial presence. The same acoustic structure serves multiple communicative functions depending on context—a many-to-one mapping between signal and meaning.

Roar chorusing coordinates group behavior. When one male roars, others join in sequence, creating choruses that can last minutes. These choruses may amplify territorial signals, coordinate predator response, or reinforce group cohesion. The function may differ across contexts while the behavior remains consistent.

Roar acoustic properties encode individual identity. Each male's roar has distinctive features that allow individual recognition. Neighbors can identify which male is roaring without seeing him. This individual signature enables relationship-specific responses—tolerating neighbors while challenging strangers.

Group composition affects roaring patterns. Groups with multiple males roar more frequently than single-male groups, possibly because male-male competition drives display elaboration. The social environment shapes communication intensity beyond what ecological factors alone predict.

For organizations, colobus demonstrate that the same signal can serve multiple functions. Town halls serve information sharing, culture building, and leadership display simultaneously. Multi-function signals are efficient but potentially ambiguous.