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Circus hudsonius

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
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
Great Britain
.

CONTENTS

* 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

DESCRIPTION

Bird
Bird
in flight at an altitude over 12,500 ft in Pangolakha Wildlife Sanctuary in East Sikkim district, India
India
in the month of November

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 flight.

BEHAVIOUR

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. 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
Scilly
, Great Britain
Great Britain
from October 1982 to June 1983.

HUNTING BEHAVIOR

This is a typical harrier, which hunts on long wings held in a shallow V in its low flight during which the bird closely hugs the contours of the land below it. Northern or hen harriers hunt primarily small mammals , as do most harriers. Up to 95% of the diet comprises small mammals.However, birds are hunted with some regularity as well, especially by males. Preferred avian prey include passerines of open country (i.e. sparrows , larks , pipits ), small shorebirds and the young of waterfowl and galliforms . Supplementing the diet occasionally are amphibians (especially frogs ), reptiles and insects (especially orthopterans ). The species has been observed to hunt bats if these are available. Larger prey, such as rabbits and adult ducks are taken sometimes and harriers have been known to subdue these by drowning them in water. Harriers hunt by surprising prey while flying low to the ground in open areas, as they drift low over fields and moors. The harriers circle an area several times listening and looking for prey. Harriers use hearing regularly to find prey, as they have exceptionally good hearing for diurnal raptors, this being the function of their owl -like facial disc. This harrier tends to be a very vocal bird while it glides over its hunting ground.

MORTALITY AND COMPETITION

Little information is available on longevity in hen harriers. The longest lived known bird is 16 years and 5 months. However, adults rarely live more than 8 years. Early mortality mainly results from predation. Predators of eggs and nestlings include raccoons , skunks , badgers , foxes , crows and ravens , dogs and owls . Both parents attack potential predators with alarm calls and striking with talons. Short-eared owls are natural competitors of this species that favor the same prey and habitat, as well as having a similarly broad distribution. Occasionally, both harriers and short-eared owls will harass each other until the victim drops its prey and it can be stolen, a practice known as kleptoparasitism . Most commonly, the harriers are the aggressors pirating prey from owls.

STATUS

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
IUCN Red List
(i.e., declining more than 30% in ten years or three generations). It is therefore classified as "least concern". In the United Kingdom, however, hen harrier populations are in a critical condition, due to habitat loss and illegal killing on grouse moors . In 2012 only 617 pairs remained, representing a fall of 20% from 2004.

RELATIONSHIP WITH HUMANS

In some parts of Europe people believed that seeing a harrier perched on a house was a sign that three people would die. Unlike many raptors, hen harriers have historically been favorably regarded by farmers because they eat predators of quail eggs and mice that damage crops. Harriers are sometimes called "good hawks" because they pose no threat to poultry as some hawks do.

FORESTRY AND HEN HARRIERS

Eggs, Collection