Neils,
If I was you, I would not go into the Kruger if you are looking for something different. The place you are staying at (Inyanga Safari Lodge) is going to offer you most of the same birds and mammals that you would see in the Kruger, so all you would be doing is seeing much of the same. Perhaps you are happy to do that and, in that case, go into the Kruger by all means. But the habitats in that area of the Lowveld are all fairly similar as is the make-up of birds. Granted, you may find a handful of additional species in the Kruger, but if you are really wanting to boost your list, you need to go somewhere else away from there.
I'm not sure if you will have access to a vehicle for your own use or whether you can arrange transport for a day trip, but in my opinion, your best bet for a day trip from there would be to head west towards the Magoebaskloof area just a little way past Tzaneen (probably about a 130-140km drive from where you are staying on good roads, so less than 2 hours drive time). This area gives you access to brilliant forest birding and higher altitude grassland birding as well, habitats you won't encounter where you are based and, therefore, will boost your bird list numbers substantially. If you consider this, it may be prudent to contact one of the local bird guides there to take you out. David Letsoalo is particularly good and can be contacted via Kurisa Moya Lodge in Magoebaskloof at
[email protected]. A day out with David will not disappoint - think of things like Orange Ground Thrush, Green Twinspot, Bat Hawk on the nest, Forest Buzzard, Black-fronted Bush Shrike, Yellow-streaked Greenbul, etc. just to mention a few. Depending on how much time you have available, you could also ask him to take you into the grasslands and boost your list with another suite of birds.
This area of the country has a great diversity of habitats and, therefore, obviously many bird species as well. This is one of the core areas that the team that the holds the record for the most species seen in SA in a 24 hour period covers and, in an area that reaches from Polokwane to Magoebaskloof, they have consistently achieved over 300 species in the last few years on Big Days.
Anyway, just thought I would throw another option into the mix... Enjoy your trip!
Kind regards
Trevor