Well, not entirely telepathic, I am just exaggerating the fact.
These frogs live in a heavy waterfalls area, and because the surrounding is so fill with the sound of water clapping, that even an explosion would be hardly notice, so their croak would never got the chance to impress their possible mate.
So, what they do? They evolve and developed ultrasound communication, which the wave spectrum is beyond Human hearing capability, their ear sunken and sharpen and their pitch raise.
The researcher also said, these frogs are the first amphibians which has ultrasound ability.
Tags: Species Frog