I wish the head was clear of the trunk, but I suspect like most owls, it is very difficult to get a clear shot at them. The face looks softer than the trunk, as if the focus may have been anterior to the face.
The thing that really jumps out at me is the heavy noise showing up in the image.
I might consider cropping down from the top a bit.
Nice eye contact and fair composition.
I think this is too noisy for ISO 800. Did you lift the exposure in post processing?
The 300/2.8 is an excellent lens, I'd use Canon teleconverter if possible.
Like this for an ID shot, it's great! Technical deficiencies have been covered already. Well done and would love to see more from your part of the world.