I think the Cleveland Zoo is somewhat photography friendly, and that's the main reason why I'm willing to drive a couple hours to visit. Yes, the more exotic animals are fenced/caged or encased in glass, but that's how it is at most zoos (at least, here in the midwest).

I bet you'd enjoy it more if you had a longer lens. 105mm is way too short for photographing zoo animals, even on a crop-sensor camera.

Also, D7100? That's a step up from the D5100.

You are apsolutly right. I am trying very hard to save up for a longer lens. Might go with a Sigma. I am pretty sure i would enjoy that. So far, loving the D7100.