The hole-in-the-head frog (Huia cavitympanum) is the only amphibian in the world known to make purely ultrasonic calls. This adaptation is thought to help it communicate against the loud background noise of the rapids it breeds in.
The hole-in-the-head frog (Huia cavitympanum), endemic to Borneo, can make and hear ultrasonic vocalisations, which allows it to breed in extremely loud streams. Mt Kinabalu, Borneo.
