I first learned this song at primary school in Adelaide (South Australia) in the late Fifties and then we were taught to sing blue-bellied joe. I was told then that it was because a sheep's belly looked blue if it was bare of wool. I accepted that then and have never thought to check it out (although I've long been back in Britain and Oz and Pom sheep may be different).
I barely heard the song in Britain for many years but suddenly it seems to have taken on a new lease of life. The Wreckers Border Morris side dance Tinners Rabbit to the tune and managed to score a first at this year's Chippenham folk festival by getting the tune on the Victorian iPod - a hand built, hand-pumped street organ and dancing to it.
Wreckers dance to ClickGo The Shears