No-one has mentioned the pub versions that have shown up in recent years, often to hymn tunes or "Banks and Braes". A typical start might be:

There were 3 crows sat on a tree and they were black as black could be.

Said one old crow unto his mate "What shall we have this day to ate (sic)."

I have collected 6 versions so far in Hampshire and Gloucestershire and also a couple of bawdy versions from members of the Royal Navy. My theory is that they came (back) into England via the 19th Century black-face minstrel shows.

Tradsinger