I recently took Canon’s EF 400mm f/4 DO IS II USM to Africa and could not have been more pleased. It is small, light and ridiculously sharp, even combined with the 1.4x Extender III on the 50.6 megapixel 5DS R body. I purchase nearly all my gear from the kind and knowledgable folks at Roberts Imaging:  https://robertscamera.com/.

Here is the equipment currently in my bag:

Canon EOS 5DS R

Canon EOS 5D Mark IV

Canon EF 400mm f/4 DO IS II USM

Canon EF 70-200mm f/4L IS II USM

Canon EF 24-70mm f/2.8L USM

Canon EF 135mm f/2.0L USM

Canon EF 85mm f/1.8 USM

Canon EF 1.4x Extender III

Manfroto Monopods

Gitzo Systematic Series 3 Tripod

Gitzo Fluid Gimbal Head

Lowepro Bags

Sandisk SD Memory Cards