My primary body is in pretty good shape for its age...73 years old, abut 6 feet tall, 215 pounds, (down from 250 just a few short years ago)and wears bifocals. Ohhhh, woops...you meant CAMERA body?
In my never-humble opinion, ANY of the Nikon digital bodies produced in the last dozen or more years will do excellently for wildlife photography. Some have fewer bells and whistles than others, but all you need for exellent photography of any kind is there!
Now...lenses...that is where it all comes down to.
Let me make a rather sweeping statement. ANY Nikon lens, unless it has had the merrie Aitch beat out of it, will be excellent for wildlife, (Parties or the kind with a leg at each corner!) with the nod given to telephotos. The "consumer" 200 mms will do much more than most folks give them credit for. F/2.8 is not irrelevant, but with adjustable ISO, F3.5-4.5 is not much of a handicap,if any at all!
Newer features just make it more convenient to use. I met a guy at Yellowstone Park, who was the photographer of a pro football team for 10-15 years,and he was using his old 400 mm (F/4.5?) manual-focus lens on some flavor of DSLR body.
Would I love to own one of the "big guns",like the 300mm F/4, 70-200 f/2.8, or the new f/4 version? O MY Yes! But, my 20-year old 70-210 AF did marvelously well until I got the 70-300VR, which also does beautifully.
Funniest thing...I find that I use it at 200mm or less most of the time...hmmmm...maybe a lesson in there, somewhere, if I could only figure out what it is.