We saw 146 species in six days, albeit that a full day was taken up driving to and from the park. It was a lot harder than I had imagined as we were mostly confined to the car and you couldn't follow up on any sightings. The best birding was in the Rest Camps at the start of each day. This obviously means that you can't get out into the Park when the camp gates open, which is the best time to be driving around as animals are still active, particularly predators. It depends what your priorities are. We did pretty well on both fronts, but looking back now I think I should have done more early morning birding. The kids probably would have thanked me for it too!
The full day by day list is below. This will give readers a view of what is common and what isn't so common. Although as mentioned most of our time was spent in the car where birding is restricted, I did of course stop very frequently, which often resulted in traffic backing up behind us assuming that we were enjoying killer views of a concealed predator. I ended up buying an "I'm a Birder" bumper sticker! The eBird trip report can be found here, and you can drill into each checklist and see numbers and so on. Of the 146 species seen, 95 were lifers, which is not entirely surprising given I had never been to that part of the continent before. There is surprisingly little overlap with the Western Cape, of the birds seen only about 40 are on that trip list, and about 10 of those are in any event global species you can see almost anywhere in either hemisphere like Grey Heron! In summary even when you're actually looking for animals you end up seeing quite a lot of birds. When you make a sustained effort you can see a lot of birds, especially within the Rest Camps.