Putty-nosed Monkey

Putty-nosed monkeys combine two call types—'pyows' and 'hacks'—to create a third meaning that neither call has alone. Pyows alone indicate general alert. Hacks alone indicate eagle. But pyow-hack sequences mean 'let's move'—a meaning unrelated to either component. This emergent meaning from combination represents a key step toward compositional semantics.

The combination is productive. Males use pyow-hack sequences to initiate group movement in various contexts, not just predator escape. The sequence has become conventionalized as a movement signal regardless of what originally motivated its evolution. Meaning has decoupled from origin.

Sequence length matters. Short pyow-hack sequences accompany short movements; long sequences accompany longer movements. The quantitative information in sequence length adds another semantic dimension. Receivers extract both the categorical meaning (move) and quantitative information (how far) from the same signal.

Other guenon species show similar combinatorial tendencies. The pattern suggests combinatorial communication evolves readily when selective pressures favor information-rich signaling. The capacity may be latent in many species, expressed when communication complexity provides fitness benefits.

For organizations, putty-nosed monkeys illustrate that combined signals can create meanings absent from components. 'All hands meeting' means something different from 'all' + 'hands' + 'meeting' taken separately. Organizational jargon works similarly—combinations acquire meanings beyond their parts.