Hi Somak...lovely colour and comp. The bird looks a tad over sharpened, and did you run alot of strong noise reduction on all but the bird? As it seems to have affected the texture of the rock. I think a rework of this image and you are gonna have a superb image!
I don't mind the placement of the bird in this comp, but I agree a vertical would be nice too. Using a combination of the clone and patch tools I would eliminate the whitewash on the rock. Some people don't mind that, but artistically speaking I would prefer the rock cleaned-up. Good pose from your subject!
P.S. Wish I could see the image in a larger version:)