Annie, unfortunately haters will be haters. My suggestion is to find a photographer that can give you honest feedback and guidance like I did. I have only been shooting for three months. Read everything you can, there's great tutorials on Youtube for free, you can get those great shots and don't let anyone tell you it's the equipment. It's mostly the technique. an f/stop here, white balance, an ISO setting there, and never forget the guideline that the shutter speed should always equal or exceed the focal length. Capturing an eagles eyes mostly depends a lot on the position of the sun. A high shutter speed, focus tracking helps, but if the Eagles eye are in shadow you won't get that reflection your looking for with any equipment. 90% of success is never giving up. It doesn't hurt to have a great lens but I am certain you can get the picture you are looking for if you are persistent and never give up.
Good luck!

Thanks! I went back and checked the Tufted Titmouse was shot with the D7100! lol

I stand corrected thanks!

I really haven't done much birding but I agree with SteveR, I have a 80-400 Nikon and it doesn't have enough reach sometimes. And I also agree with the other posters: at that distance you really should have a quality tripod or monopod. It's a super human to expect yourself not to shake at those distances. But the cost of those large pro-lenses is staggering.

No! I'm pretty sure it's a Dove though ;)

Really? you are saying the D7100 (which I own) which is a 24MP DX cropped frame camera, is sharper than the 36MP D800? and I bought my D800 with 26K shutter actuations for $1000.00 from a lady that had just been quoted $856.00 from the booth at KEH, my friend bought her other camera, a D4 for $2000.00 And you say the 200MM is not good for birds? check out the attached shot I captured last week.

Titmouse

(Download)

Morning Dove

(Download)

Save your money. Buy a used Full Frame Camera like the D800 I just found one for 1000.00 next, buy. 70-200 f/8 I also found one on Craig's list for 1000.00. Want amazing shots? Start there. You can crop close enough to count the feathers with the D800 36mp sensor. If you need to get closer, use a multiplier. Else the Nikkon 80-400mm for about $800 used
Telephoto and zoom are the same thing.