page_title: Western marsh harrier
section_title: Distribution and ecology
hierarchical_section_title: Western marsh harrier / Distribution and ecology
caption_attribution_description: English: An adult at [Hesarghatta Lake]
context_page_description: The western marsh harrier is a large harrier, a bird of prey from temperate and subtropical western Eurasia and adjacent Africa. It is also known as the Eurasian marsh harrier. The genus name Circus is derived from the Ancient Greek kirkos, referring to a bird of prey named for its circling flight, probably the hen harrier. The specific aeruginosus is Latin for "rusty".
  Formerly, a number of relatives were included in C. aeruginosus, which was then known as "marsh harrier". The related taxa are now generally considered to be separate species: the eastern marsh harrier, the Papuan harrier of eastern Asia and the Wallacea, the swamp harrier of Australasia and the Madagascar marsh harrier of the western Indian Ocean islands.
  The western marsh harrier is often divided into two subspecies, the widely migratory C. a. aeruginosus which is found across most of its range, and C. a. harterti which is resident all-year in north-west Africa.
context_section_description: This species has a wide breeding range from Europe and northwestern Africa to Central Asia and the northern parts of the Middle East. It breeds in almost every country of Europe but is absent from mountainous regions and subarctic Scandinavia. It is rare but increasing in Great Britain where it has spread as far as eastern Scotland. In the Middle East there are populations in Turkey, Iraq, and Iran, while in Central Asia the range extends eastwards as far as north-west China, Mongolia, and the Lake Baikal region of Siberia.
  Most populations of the western marsh harrier are migratory or dispersive. Some birds winter in milder regions of southern and western Europe, while others migrate to the Sahel, Nile basin and Great Lakes region in Africa, or to Arabia, the Indian subcontinent, and Myanmar. The all-year resident subspecies harterti inhabits Morocco, Algeria, and Tunisia.
  Vagrants have reached Iceland, the Azores, Malaysia, and Sumatra. The first documented (but unconfirmed) record for the Americas was one bird reportedly photographed on 4 December 1994 at Chincoteague National Wildlife Refuge in Accomack County, Virginia. Subsequently, there were confirmed records from Guadeloupe (winter of 2002/2003), from Laguna Cartagena National Wildlife Refuge in Puerto Rico (early 2004 and January/February 2006) and in Bermuda (December 2015).
  Like the other marsh harriers, it is strongly associated with wetland areas, especially those rich in common reed (Phragmites australis). It can also be met with in a variety of other open habitats, such as farmland and grassland, particularly where these border marshland. It is a territorial bird in the breeding season, and even in winter it seems less social than other harriers, which often gather in large flocks. But this is probably simply due to habitat preferences, as the marsh harriers are completely allopatric while several of C. aeruginosus grassland and steppe relatives winter in the same regions and assemble at food sources such as locust outbreaks. Still, in Keoladeo National Park of Rajasthan (India) around 100 Eurasian marsh harriers are observed to roost together each November/December; they assemble in tall grassland dominated by Desmostachya bipinnata and vetiver (Chrysopogon zizanioides), but where this is too disturbed by human activity they will use floating carpets of common water hyacinth (Eichhornia crassipes) instead – the choice of such roost sites may be to give early warning of predators, which will conspicuously rustle through the plants if they try to sneak upon the resting birds
  It hunts in typical harrier fashion, gliding low over flat open ground on its search for prey, with its wings held in a shallow V-shape and often with dangling legs.
caption: The female usually is identifiable by the rather dark plumage except the creamy crown, nape, and throat
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