This past Friday I was thrilled to spot a Northern Harrier (Circus hudsonius) at Occoquan Bay National Wildlife Refuge. I had never seen one in action before and it was cool to watch it patrol low over a field at the refuge. Harriers, unlike other hawks, rely on their sense of hearing to help capture prey, which is why they stay so close to the ground. If you want to learn more about Northern Harriers, check out the Cornell Lab of Ornithology website, one of my favorite sources of information about birds.
It was exciting to see this bird, but it sure was a challenge getting any decent shots. The harrier was a good distance away and seemed to vary its altitude in an unpredictable way. When it zoomed low, my camera wanted to focus on the ground vegetation and when it flew a bit higher, the camera sought to focus on the more distant trees, rather than on the bird that filled only a small part of the frame.
The two images below were the best that I took before the harrier disappeared from sight and show some of the features of this awesome raptor pretty well, including the face that guides sometimes describe as owl-like. It is always exciting to photograph a new species, but an inner desire to get more and better images of a new subject is sufficient motivation for me to go out again and again with my camera.
© Michael Q. Powell. All rights reserved.
Mike Powell 
Great photo. Thank you.