I've been to Tanzania, Botswana and South Africa multiple times, at least 6 trips in total. Carried a tripod once and never used it. Brought a monopod once and never used it either. If you are part of a group there is limited space in the trucks and setting up a tripod in particular can easily impinge on other's space - assuming you find a way to open the legs. The monopod held no advantage over using the beanbags provided in the trucks. If the truck is one without sides (often used in Botswana) the monopod might be helpful on occasion. I told quite a number of shots on each trip and never missed either the tripod or monopod on trips where I didn't bring one.

I've been to Africa on photo safaris 4 times. Trust me, you don't want to carry and are very unlikely to use a tripod at any point on the trip. Most of the time you're in the bush you'll be inside a vehicle and there will be no place to even open up a tripod never mind use it unless you're the only one in the vehicle. I brought a monopod on my trip last year but never once used it. Couldn't figure out how to make use of it inside the vehicle. I've been in 8 person and 14 person 4 wheel drive trucks exclusively. There just isn't that much space available that isn't taken up by the seats. As for lenses, you'll want the longest telephoto lens you own plus on other short lens for landscapes and such. Two bodies, each with a different lens attached allows for quick photos of animals that are often on the move and relatively far away from the truck. With the constant moving you will be doing, you want to keep the weight to a minimum. If you're going to be flying on bush aircraft to different landing strips, there is not much room for luggage on those aircraft and weight is an important consideration as well.