Went on a Kenya/Tanzania safari (and Rwanda gorilla trek) last month with a D700, D90, 200-400 f4 VR (with 1.4x TC), 70-200 f2.8 VR and 24-70 f2.8. The 200-400 VR was on the D90 with the TC most of the time - range is king. But having a second body with the 70-200 f2.8 was also useful for landscape shots.
If you bring the premium lenses on safari be prepared for lens envy comments from other tourists who are trying to take shots with their little P&S's!
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