It really depends upon your budget.
For under $500, you can buy a good Nikon, Canon, Fujifilm or Panasonic P&S camera with at least a 26x optical zoom which with some practice provide you with excellent wildlife shots.
If you want to do what many advanced wildlife shooter do, use a dSLR, while just about any camera will do ($600 to $8,000), it will be the lenses you buy that will make the difference in your shots.
My favorite wildlife lens is the Nikkor 200-400 mm zoom. I can attach it to either my APS-C sensored Nikon D300 for extended reach or my D3 if I need low noise under dawn or dusk shooting conditions. If you visit the Nikon web site, you can see what kind of investment you will be considering using that lens and either of those camera bodies