I learned it back in the 60's as the Umiguli bird, rather than the OO OO AA AA bird

The pygmies were the Fukawi tribe who shouted "We're the Fukawi"

And it's the Orang Utan, not the orangutan bird. It is really a large ape and is found in the mountains of Borneo rather than Africa

Chorus was almost the same:
We're off to see the wild west show
The elephant and the kangaroo-oo-oo-oo
Never mind the weather
As long as we're together
We're off to see the wild west show.