According to director Howard Hawks, all the animal captures in the picture were performed by the actual actors; no stuntmen or animal handlers were substituted onscreen. The rhino really did escape, and the actors really did have to recapture it - and Hawks included the sequence for its realism.
Composer Henry Mancini wrote a brief piece of incidental music to go with a scene where a baby elephant is taken for a walk. The simple little song became an international hit as "Baby Elephant Walk", and has been recorded by a large number of artists and in many different styles.
Much of the action sequence audio had to be re-dubbed due to John Wayne's cursing while wrestling with the animals.
One evening, Red Buttons and John Wayne were playing cards outside and a leopard came out of the bush towards them. When Buttons mentioned the approaching leopard, Wayne said, "See what he wants."
Congo, the baby elephant in the filming, died in November 2000 at the Dubbo Zoo. He was the only male elephant in captivity in Australia at the time.
Howard Hawks: He appears in at least two scenes in the movie: The first appearance is in the back of the truck when they are chasing the Rhino toward the end of the movie. He is standing on the right wearing a hat and mostly looking down/back. The second appearance is when they are standing listening to Pockets read the letter from Dallas. He walks through the hall behind the scene.