Welcome JJ! I’m new too and am surprised no one has commented on what you asked for: the composition. First, you were so lucky to get that close and he wasn’t too upset to see you (was he?). My immediate thought was: is it OK without the rear part of the body? I think so, as it’s a portrait/close-up. And you have great eye-contact. (The eyes could be just a tiny bit more in focus perhaps). Everything else about the comp. I love, the whites and greens of the bg, plus the way the antlers stand out in front of the tree trunks. In fact, I think this justifies the slight oof eyes, as in his case it’s the antlers that do the talking.
Hi Jeff! What an awesome experience and he is so beautiful looking, and seems very curious about you! Looking at your settings did you only have your camera at 59mm? If it were me I would’ve put that zoom out all the way to 300mm! Anybody correct me if I’m wrong, but I think it would help to get better focus on the eyes, like Mike mentioned. I always start at my longest zoom for anything and then back it off if necessary, usually not necessary! Hope you get to see him again!