The crybabies have a permanent place in the Animal Kingdom as full-fledged species. Researchers, for the first time, have identified ear-piercing 'screams' of a tiny amphibian in distress. But their frequency totally bypasses the human ear.
But the animals who can hear these frogs scream find it incredibly unpleasant. Interestingly, this crybaby aptitude is a survival skill for the leaf litter frog (Haddadus binotatus).
When they are attacked, they do not physically fight back but simply scream with a purported aim to repel the predators. Their screams are ultrasonic in wavelength and that's their way of defence.
The leaf litter frog (Haddadus binotatus) is the most abundant species of frog in the forest community in South America. They are tiny and the largest of the species are females. In size, they are barely up to 64 millimeters (2.5 inches) in length.
It is known that some frogs use their pipes to signal distress, warnings and alarms. A few studies have found frogs capable of emitting ultrasounds but now the new study has also confirmed it.
"Some potential predators of amphibians, such as bats, rodents, and small primates, are able to emit and hear sounds at this frequency, which humans can't," behavioural ecologist Ubiratã Ferreira Souza from the State University of Campina in Brazil said.
"One of our hypotheses is that the distress call is addressed to some of these [animals], but it could also be the case that the broad frequency band is generalist in the sense that it's supposed to scare as many predators as possible," the researcher added.
How did the scientists hear leaf litter frog?
Humans can only hear sounds around 20 kilohertz and less. The software Souza, however, can sense the sounds ranged from seven through to 44 kilohertz.
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"In light of the fact that amphibian diversity in Brazil is the highest in the world, with more than 2,000 species described, it wouldn't be surprising to find that other frogs also emit sounds at these frequencies," State University of Campina ecologist Mariana Retuci Pontes said.