Scientific name: Circus cyaneus
Identification
Photo by Laurie Campbell
Hen harriers show sexual dimorphism. The male is one of our most distinctive birds of prey, being silver-grey on top and white underneath, with a white rump and black wingtips. Females are dark brown with lighter markings on the wing and have a long grey-brown tail with dark bands. They also have a white rump. Both sexes have a disc of stiff feathers on their face, giving them an ‘owl-like’ appearance. Females are larger than males. The wings are held in a shallow ‘V’ in flight. They have a wingspan of 97-118cm.
Habitat and Distribution
Hen harriers live in open areas with low vegetation. The summer breeding season is spent in upland areas such as heather moorlands and young conifer plantations. In winter they move to lowland marshes, fenland, farmland and coastal regions. They are very widely distributed and are found throughout most of Europe, Asia and North America.
Global distribution of the hen harrier (IUCN 2011)
Diet
Hen harriers feed on small birds and mammals such as meadow pipits and voles, but may take species up to the size of hares and gamebirds. They fly low over open moorland, surprising potential prey.
Reproduction
The breeding season begins in April. Hen harriers are ground nesting birds and build nests out of a pile of vegetation, usually heather. 4-5 eggs are laid at 1-3 day intervals, leading to an obvious size difference between chicks. The incubation period is approximately 34 days, with the female doing the majority of the incubation. The male does all the hunting for the first 10-15 days after hatching and after that both adults share hunting duties. The chicks fledge after 37-42 days and remain reliant on the female for several more weeks.
Status and Threats
Hen harriers are classified by the IUCN as ‘Least Concern’. However, they are the UK’s most intensely persecuted bird of prey. Sadly there is a lot of illegal killing on grouse moors in both Scotland and England and this is the biggest threat to UK populations. There has been a 20% decrease in population size since 2004, with illegal persecution serious in England, eastern and southern Scotland.
Within the UK hen harriers are strictly protected under Schedule 1 of the Wildlife and Countryside Act 1981 and The Nature Conservation (Scotland) Act 2004. They are also included on the Red List of UK birds of conservation concern. It is an offence to intentionally take, injure or kill a hen harrier or to take, damage or destroy its nest, eggs or young. It is also an offence to intentionally or recklessly disturb the birds close to their nest during the breeding season. Violation can result in a fine of up to £5000 and/or a prison sentence of up to 6 months.
