Rough-Legged Hawk

The rough-legged hawk is a cold weather bird that breeds in the tundra and taiga regions of Arctic and Sub-Arctic Alaska and Canada and winters (November to March) in marshes, prairies and agricultural areas of extreme southern Canada and much of the U.S.

Rough-legged hawk range from All About Birds.

It is often found wintering in cold, snowy fields with patchy trees. It has developed feathers that reach to its feet to protect it from the cold climates it enjoys. When flying, it has black patches at the wrist and a white tail with a black band at the tip. Males have a smaller belly patch than females and are strongly mottled above with buff and reddish brown, streaky underparts and striped legs. There is a dark morph that can be almost entirely chocolate brown or with some mottling. 

It can hover over one spot by beating its wings quickly. It eats mostly small mammals. 

I'd never seen a rough-legged hawk before until a visit to Antelope Island and Bear River Migratory Bird Refuge on December 20. I thought they were male northern harriers which are gray above, as they have a distinctive white patch above the tail like the northern harrier. I also noted a distinctive bullseye on the back of the head, a white patch with a dark spot in the middle. 

I saw 25 or 30 of them and got photos of 13 of them. Some of my photos follow:

This female has a dark belly patch and a distinctive wrist patch. 

Other, less pronounced wrist patches. 

Bullseye patches on the back of the head. 

Some of my better close-up photos. 

Cold, snowy and icy. 

The lone rough-legged hawk I saw on Antelope Island.