In an ideal world you could have made some changes to your camera settings and composition, to make this image a lot better but we don't always live in an ideal world and in waiting to change settings/composition, you probably would have had the bird fly away by that time ... considering the situation, I think you did a good job of capturing a rare image. I've taken the liberty of post processing, hope you don't mind ... I am not a professional and I also did not spend a lot of time on it ... if the original RAW file was available, with a bit more time spent on PP, I think a lot more detail/sharpness could be achieved.
PS. Apart from cropping, all I did was very basic stuff:
1. Change white balance
2. Brighten / sharpen the eyes
3. Clone out the distractions (branches etc)
4. Blurred the background a tiny bit
... all in that order.