Hello there. I'm looking for a song that my grandfather sings to all his grandkids. He's born in 1938 if that makes a difference.
The lyrics, as far as I know, are:

Birdie, Birdie in the tree
Come and sing a song to me
Sing it loud and sing it long
Sing to me a birdie song


I've been looking for this song.. Or at least someone else who has heard it for a long time. I hope you guys can help. Thanks.