Well, canon makes some fairly good entry level DSLR's too, but I haven't kept up with gear to be honest. Wildlife in general will require a 300-400mm lens to start to be honest and nature images depending on style you'd need a F2.8 or F4 zoom in the 24/28-80/105 range.

I would read the feedback or reviews on this site on lenses you are considering to get a much brouder spectrum of views.