Hen Harrier, Circus cyaneus

Names

English: Hen Harrier
Scientific: Circus cyaneus
German: Kornweihe
Spanish: Aguilucho Pálido
French: Busard Saint-Martin

Taxonomy and Subspecies

The Northern Harrier Circus hudsonius was formerly considered to be the same species as the Hen Harrier but is not treated as a separate species [GRIN 2009].
No subspecies are known.

Size

Length: 43-52 cm
Wingspan: 100-120 cm
Weight: Male 300-400 g, Female 370-600 g

Maximum Age

16 years in the wild. [Mebs & Schmidt 2006]

Habitat

Bird of open country with short vegetation like tundra, plains, moorland, heathland, fields or meadows.

Distribution

In Europe the Hen Harrier can be found is western Europa (Spain, France, Ireland, UK), Scandinavia, Russia, Belarus. Small populations also in Ukraine, Poland or Germany. Does not breed in south-east Europe. Outside Europe in a broad band in northern Asia eastwards to the Pacific.

Migration

Birds from north and north-eastern Europe are migratory birds [Mebs & Schmit 2010]. Those birds winter in central and southern Europe in countries like Germany, Austria, France, Great Britain or Spain.
In Northern Ireland, the resident birds often stay in the uplands and only leave when the weathers gets really bad [Scott 2010].
Adult birds from Scotland mostly stay in the upland and may only move to lower ground. A few males make longer movements within the UK. Many young males from Scotland leave the area and move further south to England or even across the sea to Ireland, France, Portugal or Spain. Females make shorter movements [Etheridge 2010].

Breeding and Reproduction

Hen Harriers nest on the ground in dense vegetation. In Northern Ireland, successful tree nesting in Sitka Spruce has been observed over many years [Scott 2008, 2010].
Normally 3-6 eggs are laid which are incubated for 29-31 days. Only the female breeds and the male provides food.
The young stay in the nest for 31-38 days and after fledging the female (normally without the male) provides food for the young for another 2-3 weeks [Mebs & Schmit 2006].
For Hen Harriers, both Polygyny (a male with more than one female) and Polyandry (a female with more than one male) has also been confirmed, for example in Northern Ireland [Scott 2010].

Food and Hunting

Hunts like a typical harrier from a low flight above open country. Preferred prey are small rodents like voles. Young birds and young rabbits are also taken regularly, especially during the breeding season.

Population

Threats

Illegal killing is a serious threat, especially in the UK where the Hen Harrier is killed by game managers who manage grouse populations. Beside illegal killing, habitat destruction is the most important threat across most of Europe. The Hen Harrier cannot live very well with intensive agriculture because the prey populations are often reduced in those areas and the nests on the ground are often destroyed.

Conservation

Illegal killing must be stopped. Beside this, bird friendly agriculture should be promoted across Europe. That means less pesticides, paying farmers for wildlife friendly farming like setting aside some parts of their fields for a few years.
When harrier nests are found, farmers can leave some space around the nest which is not harvested. Farmers should be paid for the financial loss they have because of this measures.
Destroyed moorland should be restored.
Most of those measures above would also help many other species or birds including raptors like the Common Buzzard, Montagu's Harrier or the Eastern Imperial Eagle

Status IUCN/BirdLife

Least Concern (LC)

Status Global Raptor Information Network

Lower risk

Interviews about the Hen Harrier

Interview with Don Scott about the Hen Harrier in Northern Ireland

Interview with Brian Etheridge about the Hen Harrier in the UK

References

Books

Websites

BirdLife Species Factsheet for the Hen Harrier

RSPB information about the Hen Harrier

Scottish Raptor Study Groups information about the Hen Harrier

GRIN species account for the Hen Harrier