Researchers from Brazil’s State University of Campinas have made a groundbreaking discovery: small leaf litter frogs in the Amazon jungle use defensive ultrasound to signal to predators. While observing these frogs, scientists noticed their peculiar behavior of arching their backs, throwing back their heads, and opening their mouths in a way that resembled screaming. However, no sound could be heard. Later analysis revealed that the frogs were emitting high-frequency screams that were inaudible to humans.
This phenomenon, known as defensive ultrasound, is believed to be a response to predators and may signal other animals to attack the predator. The researchers recorded the distress calls on two occasions and analyzed them using specialized software. The frequency range of the calls was found to be between 7 kHz to 44 kHz, well beyond the hearing range of humans. This finding sheds light on the different ways animals communicate, some of which are undetectable by human senses.
One of the researchers, Mariana Retuci Pontes, shared that she had observed similar behavior in frogs during a previous research trip but lacked the technology to record the ultrasonic sounds. Many animals use infrasonic and ultrasonic frequencies to communicate with each other, highlighting the variety of communication methods in the animal kingdom. Despite walking through nature peacefully, there may be a hidden world of sounds that are imperceptible to human ears.
This discovery underscores how much more there is to learn about animal communication and how they interact with each other in their natural habitats. It also highlights how important it is for us as humans to understand and respect these different modes of communication when studying wildlife or interacting with animals in our daily lives.
