I believe this is a female northern harrier. But, I am a bit torn between it and a couple types of hawks that look similar.
537A9786 by kayaker72, on Flickr
537A9744 by kayaker72, on Flickr
BTW...if anyone is wondering if animal eye-AF is legit? These were hand held with serious wind gusts catching my hood and blowing my 500 mm around. It was near impossible to keep the harrier centered. Yet....I would say 90+% of the shots are in focus on the eye. Also, for what it is worth, these were electronic shutter at 20 fps.
Thanks for viewing...Brant