Hanne & Jens Eriksen / Northern harrier (Circus hudsonius) juvenile in flight. Saskatchewan, Canada, August.

Gerrit Vyn / Female Northern Harrier (Circus cyaneus) in flight. Sublette County, Wyoming, USA. May.

Gerrit Vyn / Male Northern Harrier (Circus cyaneus) in flight. Sublette County, Wyoming, USA. May.

Gerrit Vyn / Female Northern Harrier (Circus cyaneus) in flight. Sublette County, Wyoming, USA. May.

Loic Poidevin / Hen harrier (Circus cyaeneus) in flight, Nome, Alaska, USA, August

Marie Read / Northern harrier (Circus cyaneus) pair exchanging food in courtship while flying near nest, Montezuma National Wildlife Refuge, New York, USA.

Karine Aigner / Northern harrier (circus cyaneus) drinking at water's edge, Texas, USA. April.

John Chan / Northern Harrier (Circus cyaneus) perched on a dead branch preening, Bolsa Chica Ecological Reserve, Southern California, USA, December.

Charlie Summers / Northern harrier (Circus hudsonius), two juvenile females hunting. North Park, Colorado, USA. August.

John Chan / Juvenile female Hen harrier (Circus cyaneus) regurgitating a pellet as shorebirds fly by in foreground, Bolsa Chica Ecological Reserve, Southern California, USA, November.

John Chan / Juvenile female Hen harrier (Circus cyaneus) perched on the ground, with shorebirds foraging in foreground, Bolsa Chica Ecological Reserve, Southern California, USA, November.

Marie Read / Northern Harrier (Circus cyaneus) male in flight over field at sunset in winter, Ulster County, New York, USA