Thanks for the link, Dale. Looks like I have my answer.

"Fly down, fly down, you little bird, and alight on my right knee. Your cage will be of purest gold, in deed of property."

Sounds a bit archaic, but it makes some sense.

Last night I worked in some lines from one of Child's variants and wrote a few more in order to make the idea of the tattle tale bird a little clearer.

"There was a pretty parrot bird perched high upon a tree And with an eye both keen and sharp saw the murder of Henry Lee. He looked the Lady in the eye from up upon his limb Saying 'You have cut down poor Henry Lee and in a well did throw him in'."

A little clumsy, but it sounded OK when I sang it.

Bryant