I usually prefer subjects in better condition than this guy, but I really think in this case the dishoveled plumage and cracked bill give this guy some character. I agree a bit more room above would be better comp-wise, and some of the darker spots on the BG are a bit distracting. Some fill may have helped you get some detail in the blacks. Good portrait:).
Interesting-looking species, the bill is quite impressive. Head angle and sharpness look good, I would only try to get more details in the blacks, it should work best in the RAW file using curves.