This is a lot of fun to watch, I've seen it quite a few times, own the soundtrack (am playing it now - has the cool "Maeba" african song) and am a big fan of Biba the Chimp! ;-) Giuliano Gemma gets a chance to play a comic role tailored specifically for him, Ursula Andress is very sexy and Jack Palance chew up the scenery at every turn. This film had a sequel called Safari Express with the same cast as the original, but is harder to find. To add to the confusion, some distributors released both this movie and the sequel as "Tropical Express"!! I still recommend this as a great family film. Kids will love the animals and parents will appreciate the intelligent humour. Then the parents might kill the kids if they don't stop saying "Maeba" around the house.
Too bad there were only two in this series. Maybe it's not too late for a reunion? :o)