Hi Wendy - As one bird shot tyro to another I probably can't help much. You don't say whether you used a tripod. If not then that might be one way to start to get a sharper image, along with setting the focus point to exactly where the bird is, probably using manual focus. For PP, a sharpening technique other than Unsharp Mask might be useful. In the Gimp (which I use), there is a technique called wavelet sharpening that helps in this type of case. Another possibility is to use refocusing software. There are plug-ins for most software packages available for download. A third possibility is to try a small amount of local contrast enhancement. Finally, in this particular case, I would duplicate the layer and blend with Screen to give extra exposure to the bird itself. You might find that this brings out more detail.
Cheers
David
PS Here's an attempt - hope you don't mind me pinching your shot. Pixel count is low - it would look better working from original.