I don't think I can buy the "Kitty Kline" connection, either. Here's another version of "Birdie":
LITTLE BIRDIE
Little birdie, little birdie,
What makes you fly so high?
It's because I am a true little bird
And I do not fear to die.
Little birdie, little birdie,
What makes your wing so blue?
It's because I've been a-grievin',
Grieving after you.
Little birdie, little birdie,
What makes your head so red?
Well, after all that I've been through,
It's a wonder I ain't dead.
Little birdie, little birdie,
Come sing to me a song.
I've a short while to be here
And a long time to be gone.
Source: Silber & Silber, Folksinger's Wordbook (1973), Oak Publications
C G
Little birdie, little birdie,
C
What makes you fly so high?
G
It's because I am a true little bird
C
And I do not fear to die.
The Silber & Silber book has no tune, but Jerry Silverman's Folk Song Encyclopedia has identical lyrics and a tune (which I don't like completely).