Really nice image, you've captured fantastic detail in the face and fur and I love the tight framing of the subject. The only way I can see for this image to improve would have been to capture him with his eyes open, the eyes can portray lots of emotion in an image like this. Outstanding work, looking forward to your other shots.
I don't know what suggestions I can offer to you isaacp. I think this is a great shot. The Oranguatan is captured in a really natural un-zoo-like pose. I find it difficult to be critical of this one. Though I do wonder how different an impression of this glorious ape I would have if the shot had captured him with his eyes open. Added to my favourites straight-away! I look forward to seeing more!
Cheers............