This medium-sized raptor breeds on moorland, bogs and (in Europe) farmland. The nest is on the ground. Four to six whitish eggs are laid.
In winter, the Hen Harrier is a bird of open country, and will then roost communally, often with Merlins and Marsh Harriers. There is now an accepted record of transatlantic vagrancy by the American subspecies, with a juvenile being recorded in Scilly, Great Britain from October 1982 to June 1983.
This is a typical harrier, with long wings held in a shallow V in its low, contour-hugging, flight. Hen Harriers hunt small mammals and birds, surprising them as they drift low over fields and moors. This harrier tend to be a very vocal bird while it glides over its hunting ground.