Large odorous frogs (Odorrana graminea) produce ultrasonic calls

We present the first data on the vocalizations of large odorous frogs (Odorrana graminea, previously Odorrana livida), from southern China. The males produce diverse broadband signals most of which contain ultrasonic harmonics. Six basic call-types were identified based on the number of call notes, fundamental frequency, call/note duration, frequency modulation patterns and spectral composition. O. graminea is one of only a few non-mammalian vertebrates able to detect ultrasound, but its tympanic membranes are not recessed. These results should stimulate further studies to provide new insights into the mechanisms underlying high-frequency communication in anurans.