Cuckoo, cuckoo, what do you do?
In April I open my bill;
In May I sing all day;
In June I change my tune;
In July away I fly
In August away I must.
Adhering to the formula above, the cuckoos in my area began singing in April, filled the air with their calls all through May and early June, and changed their tune in the latter part of June and early July. Moreover, I have not heard any cuckoo calls at all in the past two weeks, which suggests the cuckoos here have flown away, just as the nursery rhyme said they would. The last line in the rhyme is still a bit of a mystery to me. Perhaps it refers to the young cuckoos leaving the nests of their host parents?