Peatland wildlife

Hen harrier (Circus cyaneus)

Hen harrier (Circus cyaneus)

Description

The Hen harrier is a spectacular bird of prey that lives in upland areas up to about 500m in Northern Ireland. Adult males are blue-grey with black wing-tips and a white rump. Females and immature birds are brown with a barred tail and white rump. The tail is long and hen harriers have a wing span of up to 120cm. The harrier's face feathers are arranged into a disk. This helps it to listen out for prey as the feathers form a groove, which directs sound waves to the ear opening.

Behaviour

Hen harriers feed mainly on smaller birds during the breeding season, but will occasionally take mammals up to the size of a hare and are notorious for taking wounded gamebirds. They hold their wings in a shallow 'V' shape when gliding and often fly low over peatland searching for prey.

Breeding

As they are predominantly a ground-nesting species, hen harriers prefer open habitats such as blanket bog and heathland when choosing nest sites. They also nest in young conifer plantations, and have recently started to nest in the crowns of storm damaged conifers in Northern Ireland. This behaviour has not been recorded anywhere else.

The nest is a shallow cup loosely constructed with any available plant material. Occasionally a male can be polygamous, mating with and providing for two or more females. The female normally lays four or five eggs between April and the end of May and incubates them for 29-32 days. The chicks are extremely active, seeking cover in the neighbouring vegetation as they get older and eventually fledging at 29-39 days. Outside of the breeding season, hen harriers sometimes gather in communal roosts of up to 20 birds.

Status

Local

The decline in hen harrier populations is most likely due to loss of suitable habitat for hunting and nesting. In Northern Ireland it is protected by special penalties at all times under Schedule 1 of the Wildlife Order. It is also a Priority Species for conservation in Northern Ireland. A number of the most important sites for breeding hen harrier have already been declared as Areas of Special Scientific Interest.

European

The Hen harrier is listed in Annex I, of the Birds Directive, Appendix III of the Bern Convention and Appendix II of the Bonn Convention.