Behavior and Ethology Commons^™

Why Do Caterpillars Whistle? Acoustic Mimicry Of Bird Alarm Calls In The Amorpha Juglandis Caterpillar, Jessica Lindsay

Undergraduate Theses, Professional Papers, and Capstone Artifacts

Caterpillar species possess a range of anti-predator defenses, from regurgitation to sonar jamming. The North American walnut sphinx caterpillar (Amorpha juglandis) produces a variety of whistling noises when pinched. Limited observations indicate that this causes avian predators to retreat, leaving the caterpillar alone. However, it is unknown why this whistle is such an effective deterrent. Interestingly, the A. juglandis whistle is acoustically similar to the “seet” alarm call that many bird species produce in response to their own predators. We propose that the A. juglandis whistle is a form of acoustic mimicry, in which the caterpillar protects itself …