The movie dramatizes the work of the team which pioneered the first successful method of capturing Rhinos and transporting them to captivity. This involved darting the animals with anesthetic and hauling the unconscious beasts to a pen where they recovered and were tamed for a few weeks before being shipped off to be part of breeding programs in zoos across the world. In 1964 the year this movie was made, a shipment of Rhino was made from Umfolozi to San Diego zoo in California.
In an interview during the filming, Dr Ian Player expressed the fervent wish to "be able to bulldoze Johannesburg flat and let animals roam free there".
Shirley Eaton said she got to know the game wardens in Umfolozi, South Africa where they were filming. They were catching rhinos to send them to other places to breed, and they named one after her. They always put "Um-" before names, so the lady rhino was called Umeaton. Eaton thought that was a great privilege.