The adult male has grey upperparts and breast, contrasting with pale underparts and distinctive black wingtips.
The adult female and juveniles of both sexes have brown upperparts and buffish-white underparts that are heavily streaked.
All age groups and sexes have a prominent white rump. As with most raptor species the females are typically larger than males.
Hen harriers perform spectacular courtship flights called ‘sky dancing’ and males will sometimes pair with two females in two separate nests, known as a polygynous mating system.
This species can be found in the uplands during spring and summer where it breeds on open moorlands and in young forest plantations. It usually nests on the ground, although the rare phenomenon of tree-nesting has been recorded in Northern Ireland.
In the winter it also moves to open lowland areas and congregates at communal roosts.
Hen harrier diet includes small birds, mammals, reptiles and amphibians.
Males and females can be observed doing spectacular food pass behaviours when transferring food in mid-air.
Top left (adult male in flight), bottom left (adult male perched); top right (adult female in flight) & bottom right (adult female perched)