The agonies over this little round have been going on for years!!! What is its mysterious interest? I will guess that it's based upon every soul of us wanting our own childhood (or campfire) memories to be The Right Way to Sing It.... all agree?

My guess about the "poor bird" (Ah, poor bird, take thy flight- High above the sorrows of this sad night) is that it fits as a harmony sung at the same time as the Rose Round. The "poor bird" lyrics are certainly not metrically right for being sung with it as a round.
Selah.    Jean