Female Concave-eared Frogs Draw Mates With Ultrasonic Calls
 

Most female frogs don't call; most lack or have only rudimentary vocal cords. A typical female selects a mate from a chorus of males and then -- silently -- signals her beau. But the female concave-eared torrent frog, Odorrana tormota, has a more direct method of declaring her interest: She emits a high-pitched chirp that to the human ear sounds like that of a bird.



More...