The Nikon kit lens will give you a decent wide angle.
You might consider a longer telephoto, with a tripod of course. 500 mm f/8 mirror lenses are fun & inexpensive, and with your camera and its 1.5x multiplication factor, you could get nice & close to any wildlife you see. Just remember the tripod. It will[/b] be worth carrying around.
Lots of people like wide angle zooms, aside from very tight spaces, I don't see it being of that much use.
A 100 mm macro lens could also be useful, if you see something on a smaller scale you want to photograph. Macros are neat because they are so darned sharp and distortion-free. I had a revelation when I compared the results obtained from a Tokina ATX 90 mm 2.5 macro to anything else I'd previously shot with in that range. This can double as a good protrait lens, though you may have to use a softening filter in some cases.
Aside from that, I'd invest in more memory, so that you can afford to shoot everything in raw format for the best possible tonal range. That will help ALL of your pictures just a bit, though you won't always be able to see it.
Do you have a good tripod? That is essential, IMO. By good, I don't necessarily mean you have to spend over $100. I have a Slik U8000 that is versatile & lightweight, with interchangeable shoes that cost only $60. Even more handy, but less versatile is the tiny Bogen one with the ballhead. This one ALWAYS comes with me, and it has saved my bacon a few times for those times when I wound up shooting a night shot when I wasn't expecting to. This little one was only $40, and probably the most useful accessory I've ever bought.