Sounds & Calls
Southern Cassowary (Casuarius casuarius)
The call of the cassowary is one of the lowest frequency sounds made by any bird. More of a non-vocal sound than a ‘call’, cassowaries create this booming rumble from deep within. With head tilted down toward the ground, its whole body shudders as the sound is produced. While scientists are not sure exactly what internal mechanism creates the sound, it is clear from watching a cassowary that it uses its body as an amplifier in some way. When you hear this sound in the wild, you ‘feel’ the sound as it vibrates through the air. It sounds more like a noise made by a large mammal than a bird.
Going to as low as 24Hz, these deep calls are bordering on ‘infrasound’. Low-frequency sounds carry a significant distance and are no doubt an effective way for cassowaries to communicate in dense rainforest.