A lovely specimen you've captured here, but unfortunately I cannot help you with the ID either.
Actually this was probably a rather difficult shot, the way I see it. This was due to a couple of factors. The backlight (or at least glare) the focal distance, and the dark bird. The backlight or bright sky fooled the cameras sensors and this was even more enhanced by the dark bird on which you focused. This is always going to remain a problem shot due to the major difference in contrast between the BG and the subject i.e. the bright sky and the dark bird and unless you can get some light on to the bird there is really not much you would be able to change about this matter.
However some other suggestions I might have would concern the DOF and ISO settings. Since the bird is not such a big subject I don't believe it was necessary to select such a wide aperture as f/13 at such a focal distance of the full 300mm of you lens. You could have narrowed the aperture right down to ±f/5.6 and that would have provide sufficient DOF for this bird to keep everything in focus for the entire range of the bird, but you would have gain a heck of a lot on shutter speed, probably to the region of ±1/1200 of a second. This means that you would have had ample light to work with and the spin off would be that you could have improved on the ISO setting by shifting it down to 200 or even 100 and still have sufficient shutter speed to have a nice crispy sharp photo. One other suggestion I would like to make, and I know it is difficult in these conditions because branches don't want to grow where we want them to be, but if possible try not to dissect an animal or a bird’s neck with a twig or a branch.
Anyway, well done under this trying circumstances and TFS.
PS. Sorry, but it's a bit difficult for me to do a proper analysis / critique on the moment since my monitor is under "house arrest" at the repair agents and I don't know when I'll get it back. The one on loan is small and not so great, but I have to make do for the time being.
My First Hawk (31)