The Hen Harrier Circus cyaneus is a bird species of high conservation concern. It is listed on Annex I of the EU Birds Directive. The Hen Harrier population has decreased alarmingly due to habitat loss and persecution. The male Hen Harrier has silver-blue upperparts and is white underneath with broad black tips to the wings. The wingspan of adult males can vary between 97 and 109cm. The female is larger than the male and has a soft brown plumage with contrasting patterns under the wings with a white rump just above the tail. The wingspan of adult females varies between 111 and 122 cm.
The male attracts the female by an elaborate sky dance, soaring and swooping. When a pair forms, they chose their location very carefully. Hen Harriers in Ireland will typically nest in heather bogs, young forestry, scrub and mountain glens. The female lays her eggs in the warm soft nest which she and the male have carefully built on the ground made of grass, twigs and heather. The harriers chose a secret location where it is hard for predators and humans to find their nest. Once the eggs are laid the male will provide food for the female and when the chicks are hatched for them too. The female will fly up to meet the male, but not directly up from the nest so as to disguise the nest location. As the male drops the food to her, she will turn over and catch the food.