"Quang's tree frog [...] has a hyperextended vocal repertoire—in other words, it doesn't just repeat the same call over and over, but has a number of types of calls. In fact, no two calls that I recorded were exactly the same, with each frog mixing clicks, whistles and chirps in no apparent order! It is the most variable frog call that I've heard of, and sounds a lot more like a bird song than a frog call [click here to listen to the frog's call]," lead author Jodi Rowley with the Australian Museum in Sydney told mongabay.com.

Unlike Quang's tree frog, Rowley says the majority of frog species stick to one note to attract females.

"[Most male frogs] call to attract females with a rather repetitive call (eg. the familiar "croak, croak, croak" or "chirp, chirp, chirp", for example). While each species has a different call (it helps prevent females attracting frogs of the wrong species!), most frog advertisement calls are of roughly one type of call, repeated until they get the girl."