The hen harrier (Circus cyaneus) is a bird of prey. The genus name Circus is derived from Ancient Greek kirkos, meaning 'circle', referring to a bird of prey named for its circling flight. The specific cyaneus is Latin, meaning "dark-blue". While many taxonomic authorities split the northern harrier and the hen harrier into distinct species, others consider them conspecific. It breeds in northern Eurasia. The term "hen harrier" refers to its former habit of preying on free-ranging fowl. It migrates to more southerly areas in winter. Eurasian birds move to southern Europe and southern temperate Asia, In the mildest regions, such as France, Great Britain.
1 Description 2 Behaviour
2.1 Hunting behavior 2.2 Mortality and competition
3 Status 4 Relationship with humans 5 Forestry and hen harriers 6 References 7 External links
The hen harrier is 41–52 cm (16–20 in) long with a
97–122 cm (38–48 in) wingspan. It resembles other
harriers in having distinct male and female plumages. The sexes also
differ in weight, with males weighing 290 to 400 g (10 to
14 oz), with an average of 350 g (12 oz), and females
weighing 390 to 750 g (14 to 26 oz), with an average of
530 g (19 oz). Among standard measurements, the wing
chord is 32.8 to 40.6 cm (12.9 to 16.0 in), the tail is 19.3
to 25.8 cm (7.6 to 10.2 in) and the tarsus is 7.1 to
8.9 cm (2.8 to 3.5 in). It is relatively long winged and
long tailed, having the longest wing and tail relative to its body
size of any raptor occurring in North America.
The male is mainly grey above and white below except for the upper
breast, which is grey like the upperparts, and the rump, which is
white; the wings are grey with black wingtips. The female is brown
above with white upper tail coverts, hence females, and the similar
juveniles, are often called "ringtails". Their underparts are buff
streaked with brown.
In Eurasia, the adult male is sometimes nicknamed the "Grey Ghost",
because of his striking plumage and spectral aura.
The female gives a whistled piih-eh when receiving food from the male,
and her alarm call is chit-it-it-it-it-et-it. The male calls
chek-chek-chek, with a more bouncing chuk-uk-uk-uk during his display
This medium-sized raptor breeds on moorland, bogs, prairies, farmland
coastal prairies, marshes, grasslands, swamps and other assorted open
areas. A male will maintain a territory averaging 2.6 km2
(1.0 sq mi), though male territories have ranged from 1.7 to
150 km2 (0.66 to 57.92 sq mi).
These, are the one of the few raptorial birds known to practice
polygyny – one male mates with several females. Up to five females
have been known to mate with one male in a season. A supplementary
feeding experiment on the Orkney islands showed that rates of polygyny
were influenced by food levels; males provided with extra food had
more breeding females than 'control' males that received no extra
The nest is built on the ground or on a mound of dirt or vegetation.
Nests are made of sticks and are lined inside with grass and leaves.
Four to eight (exceptionally 2 to 10) whitish eggs are laid. The eggs
measure approximately 47 mm × 36 mm (1.9 in
× 1.4 in). The eggs are incubated mostly by the female for
31 to 32 days. When incubating eggs, the female sits on the nest while
the male hunts and brings food to her and the chicks. The male will
help feed chicks after they hatch, but does not usually watch them for
a greater period of time than around 5 minutes. The male usually
passes off food to the female, which she then feeds to the young,
although later the female will capture food and simply drop into the
nest for her nestlings to eat. The chicks fledge at around 36 days
old, though breeding maturity is not reached until 2 years in females
and 3 years in males.
In winter, the hen harrier is a bird of open country, and will then
roost communally, often with merlins and marsh harriers. There is now
an accepted record of transatlantic vagrancy by the northern harrier,
with a juvenile being recorded in Scilly,
This species has a large range. There is evidence of a population
decline, but the species is not believed to approach the thresholds
for the population decline criterion of the
IUCN Red List
Eggs, Collection Museum Wiesbaden
The hen harrier is a bird of open habitats such as heather moorland and extensive agriculture. However, much of its range, particularly in Ireland and parts of western Britain, has been (and continues to be) afforested, predominantly with non-native conifers such as Sitka spruce (Picea sitchensis) from North America. Hen harriers nest and forage in commercial forestry when it is young, before the canopy closes (typically at between 9–12 and years old), but do not make much use of thicket and subsequent growth stages, which typically comprise between 2⁄3 and 3⁄4 of the commercial growth cycle. Where forests replace habitats that were used by hen harriers they will therefore tend to reduce overall habitat availability. However, where afforestation takes place in areas that were previously underutilised by hen harriers, it may increase the value of such areas to this species in the long-term. Areas dominated by forestry may remain suitable to hen harriers provided that a mosaic of age classes is maintained within the forest, such that areas of young, pre-thicket forest are always available. References
^ a b
BirdLife International (2013). "Circus cyaneus". IUCN Red List
of Threatened Species. Version 2013.2. International Union for
Conservation of Nature. Retrieved 26 November 2013.
^ Jobling, James A. (2010). The Helm Dictionary of Scientific Bird
Names. London: Christopher Helm. pp. 109, 126.
^ Etherington, Graham J.; Mobley, Jason A. (2016-01-01). "Molecular
phylogeny, morphology and life-history comparisons within Circus
cyaneus reveal the presence of two distinct evolutionary lineages".
Avian Research. 7: 17. doi:10.1186/s40657-016-0052-3.
^ "Hen harrier". RSPB. Retrieved 2016-01-19.
^ a b c d del Hoyo, J.; Elliott, A.; Sargatal, J., eds. (1994).
Handbook of the Birds of the World. Volume 2: New World Vultures to
Guineafowl. Barcelona: Lynx Edicions. ISBN 84-87334-15-6.
^ a b Mullarney, Killian; Svensson, Lars; Zetterstrom, Dan; Grant,
Peter (1999). Collins
Wikimedia Commons has media related to Circus cyaneus.
The Langholm Moor Demonstration Project
Field Guide Page on Flickr
Range in Iran (in Persian)
Ageing and sexing (PDF; 4.3 MB) by Javier Blasco-Zumeta &
Wd: Q25572 ADW: Circus_cyaneus ARKive: circus-cyaneus Avibase: F558C7F96E40C134 eBird: norhar1 EoL: 1049123 EPPO: CIRKCY Fauna Europaea: 96711 GBIF: 2480487 IBC: hen-harrier-circus-cyaneus iNaturalist: 5170 ITIS: 175430 IUCN: 22727733 NCBI: 43466 Species+: