|পূৰ্ণবয়স্ক মতা (সন্মুখত), পোৱালি (মতা ডবাশেনৰ কাষত) আৰু পূৰ্ণবয়স্ক মাইকী (পিছফালে) ডবাশেন|
|বৰ্গ:||Falconiformes (but see there)|
|Dark green: present all year|
Light green: nesting only
Blue: wintering only
The Western Marsh-harrier is 43 to 54 cm in length, and has a wingspan of 115 to 130 cm and a weight of 400 to 650 g in males and 500 to 800 g in females. It is a large, bulky harrier with fairly broad wings, and has a strong and peculiar sexual dichromatism. The male's plumage is mostly a cryptic reddish-brown with lighter yellowish streaks, which are particularly prominent on the breast. The head and shoulders are mostly pale greyish-yellowish. Whether from the side or below, flying males appear characteristically three-colored brown-grey-black. The legs, feet, irides and the cere of the black bill are yellow.
The female is almost entirely chocolate-brown. The top of the head, the throat and the shoulders have of a conspicuously lighter yellowish colour; this can be clearly delimited and very contrasting, or (particularly in worn plumage) be more washed-out, resembling the male's head colors. But the eye area of the female is always darker, making the light eye stand out, while the male's head is altogether not very contrastingly colored and the female lacks the grey wing-patch and tail. Juveniles are similar to females, but usually have less yellow, particularly on the shoulders.
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.
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.
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
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.
The start of the breeding season varies from mid-March to early May. Western Marsh-harrier males often pair with two and occasionally three females. Pair bonds usually last for a single breeding season, but some pairs remain together for several years.
The ground nest is made of sticks, reeds and grasses. It is usually built in a reedbed, but the species will also nest in arable fields. There are between three and eight eggs in a normal clutch. The eggs are oval in shape and white in colour, with a bluish or greenish tinge when recently laid. The eggs are incubated for 31–38 days and the young birds fledge after 35–40 days.[উদ্ধৃতিৰ প্ৰয়োজন]
স্থিতি তথা সংৰক্ষণ[সম্পাদনা কৰক]
The Western Marsh-harrier declined in many areas between the 19th and the late 20th centuries due to persecution, habitat destruction and excessive pesticide use. It is a now a protected species in many countries. Its numbers are rising again in many places, most notably perhaps in Great Britain, where a single breeding female was left in 1971, whereas today over 200 pairs are present.
It still faces a number of threats, including the shooting of birds migrating through the Mediterranean region. They are vulnerable to disturbance during the breeding season and also liable to lead shot poisoning. Still, the threats to this bird have been largely averted and it is today classified as Species of Least Concern by the IUCN.
- BirdLife International (2012). "Circus aeruginosus". IUCN Red List of Threatened Species. Version 2012.1. International Union for Conservation of Nature. http://www.iucnredlist.org/apps/redlist/details/106003399। আহৰণ কৰা হৈছে: 16 July 2012.
- N.N. Dutta et al, Annals of Biological Research, 2011, 2 (5):374-384
- "আৰ্কাইভ কপি". Archived from the original on 2012-02-19. https://web.archive.org/web/20120219015953/http://www.rbbp.org.uk/downloads/rbbp-report-2008.pdf। আহৰণ কৰা হৈছে: 2013-05-12.
- Clarke et al. (1998)
লগতে চাওক[সম্পাদনা কৰক]
- American Ornithologists' Union (AOU) (2000): Forty-second supplement to the American Ornithologists' Union Check-list of North American Birds. Auk 117(3): 847–858. DOI: 10.1642/0004-8038(2000)117[0847:FSSTTA]2.0.CO;2 PDF fulltext
- Banks, Richard C.; Cicero, Carla; Dunn, Jon L.; Kratter, Andrew W.; Rasmussen, Pamela C.; Remsen, J.V. Jr.; Rising, James D. & Stotz, Douglas F. (2005): Forty-sixth supplement to the American Ornithologists' Union Check-list of North American Birds. Auk 122(3): 1026–1031. DOI: 10.1642/0004-8038(2005)122[1026:FSTTAO]2.0.CO;2 PDF fulltext
- Clarke, R.; Prakash, V.; Clark, W.S.; Ramesh, N. & Scott, D. (1998): World record count of roosting harriers Circus in Blackbuck National Park, Velavadar, Gujarat, north-west India. Forktail 14: 70-71. PDF fulltext
- Merkord, Christopher L.; Rodríguez, Rafy & Faaborg, John (2006): Second and third records of Western Marsh-Harrier (Circus aeruginosus) for the Western Hemisphere in Puerto Rico. Journal of Caribbean Ornithology 19(1): 42-44. PDF fulltext Archived 2007-10-09 at the Wayback Machine
- Verma, Ashok (2002): A large roost of Eurasian Marsh Harriers Circus aeruginosus at Keoladeo National Park, Bharatpur, India. Forktail 18: 150-151. PDF fulltext
- Clarke, Roger (1995): The Marsh Harrier. Hamlyn, London.
- Forsman, Dick (1999): The Raptors of Europe and The Middle East: a Handbook of Field Identification. T & A D Poyser, London.
- Snow, David W. & Perrins, Christopher M. (eds.) (1998): The Birds of the Western Palearctic (Concise ed., Vol. 1). Oxford University Press. ISBN 0-19-854099-X
বাহ্যিক সংযোগ[সম্পাদনা কৰক]
|ৱিকিমিডিয়া কমন্সত ডবাশেন সম্পৰ্কীয় মিডিয়া ফাইল আছে।|
- RSPB - Marsh harrier
- Birds of Britain - Marsh Harrier Archived 2007-02-10 at the Wayback Machine
- (Western Marsh Harrier = ) European Marsh Harrier - Species text in The Atlas of Southern African Birds
- Internet Bird Colloection Videos
- Oiseaux Text, map, photos.
- Ageing and sexing (PDF; 5.7 MB) by Javier Blasco-Zumeta & Gerd-Michael Heinze