So i know this is like two years later but i heard a different version of this song that i can't seem to find any where but on this one kids rthyme c.d. it goes:

The cuckoo she's pretty
She sings as she flys
She brings us good tidings
She tells us no lies
She sucks on white flowers
As to keep her vioce clear
and the more she sings Cuckoo
The summer draws near