Frank (Bring 'em back alive) Buck was very famous as a result of the Travelogue Movies that featured him as trapper and importer of wild animals while on safari in Africa. John Ringling North hired him in 1938 and featured him in a Spec with a jungle theme where he simply entered riding a double-howdah bourne by two elephants. The illusion was that he had just freshly returned from Safari with all these animals (a hippo and a giraffe had been trained to walk in this pageant) but all the animals were long time Ringling menagerie stock.
I had a glossy portrait like the one shown above autographed to my dad from Mr. Buck but I have misplaced it. More frustrating to me however is trying to figure out when their paths might have crossed.I don't recall him ever mentioning the incident.