Bert, I have a recording I made from BBC's Folk on II in around 1980 of someone singing "Song of the Thrush." The elderly man had called the show, and they'd recorded him singing on the phone.

I learned a version of this parody of The Trail of the Lonesome Pine from my father. (At a very young age. Wonder where my twisted sense of humor comes from.) I've never heard anyone else sing it, but I did run into someone once who was familiar with the song. The version I got from my dad goes:

In the Blue Ridge Mountains of Virginny
Stood a cow on the railroad track
She was a good old cow with eyes so fine
But you can't expect a cow to read a railroad sign
She stood
In the middle of the track
And the train
Hit her square in the back
Now her horns hang on the Blue Ridge Mountains
And her tail's on a lonesome pine

This is in "A Prairie Home Companion Folk Song Book" (AKA "Joe's Got a Head Like a Ping-Pong Ball") but they completely miss the play on the title of the original song in the last line.