First off - nice image. I like the wing positions, the head position (looking where it's going), spread tail feathers, feet with talons ready to land. Details are sharp. Also like the small bit of grass and flowers in the photo. Colors of the bird and perch (rock) and background work very well together.
Question: I really like the composition. If mine I would have probably cropped the right hand side more than you have because I would think that there was too much open space on that side - but then I don't think it would work as well as your composition. My question is why. Is it because of the line of the rock and the second wing leading one's eye that way? (hope you don't mind the question, just trying to learn).
Thanks guys for the comments. Deb, the comp for me has three elements. Firstly as you said to create the diagonal with the wing and secondly to include a bit of space through which to convey the vastness of the settimg. Lastly, it looked good after several tries.:)
Lee, in some instances the 500 was a bit too much on the 7D and then in others it worked perfectly. Having used both, I reckon that the best focal length on a 1.6 body at GC is 400mm. On the 1.3 bodies, the 500.