I know about this in the late eighties when I met a wildlife documentary maker in the tropics. His studio had a miniature cave (a very tiny thing) and also kept wild animals in a large enclosures for more wild life shots. Any other way and it would have been impossible to document some of the things at the time.
The animals he kept became the start of the Belize Zoo. He unceremoniously wanted to rid of the animals (by euthanasia if necessary) when he was done with filming. The woman he hired as animal manager didn't want to do that and she took them over and started charging people to see them in order for them to be fed.
That I think is a more interesting story. What is the provenance and future of some of the animals that end up in documentaries.