The large-billed reed warbler (''Acrocephalus orinus'') is an
Old World warbler
Old World warblers are a large group of birds formerly grouped together in the bird family Sylviidae. The family held over 400 species in over 70 genera, and were the source of much taxonomic confusion. Two families were split out initially, the ci ...
in the genus ''
Acrocephalus''. The species has been dubbed as "the world's least known bird". It was known from a single specimen collected in India in 1867 and rediscovered in the wild in
Thailand
Thailand ( ), historically known as Siam () and officially the Kingdom of Thailand, is a country in Southeast Asia, located at the centre of the Indochinese Peninsula, spanning , with a population of almost 70 million. The country is bo ...
in 2006. The identity of the bird caught in Thailand was established by matching
DNA sequences extracted from
feather
Feathers are epidermal growths that form a distinctive outer covering, or plumage, on both avian (bird) and some non-avian dinosaurs and other archosaurs. They are the most complex integumentary structures found in vertebrates and a premier ...
s; the bird was released. After the rediscovery in the wild a second specimen was discovered amid ''
Acrocephalus dumetorum
__NOTOC__
Blyth's reed warbler (''Acrocephalus dumetorum'') is an Old World warbler in the genus '' Acrocephalus''. It breeds in the Palearctic and easternmost Europe. It is migratory, wintering in Bangladesh, India and Sri Lanka. It is one of th ...
'' specimens in the collections of the
Natural History Museum at Tring
The Natural History Museum at Tring was the private museum of Lionel Walter, 2nd Baron Rothschild; today it is under the control of the Natural History Museum, London. It houses one of the finest collections of stuffed mammals, birds, reptiles ...
. A breeding area was found in
Afghanistan
Afghanistan, officially the Islamic Emirate of Afghanistan,; prs, امارت اسلامی افغانستان is a landlocked country located at the crossroads of Central Asia and South Asia. Referred to as the Heart of Asia, it is bordere ...
in 2009 and studies in 2011 pointed to its breeding in
Kazakhstan
Kazakhstan, officially the Republic of Kazakhstan, is a transcontinental country located mainly in Central Asia and partly in Eastern Europe. It borders Russia to the north and west, China to the east, Kyrgyzstan to the southeast, Uzbeki ...
and
Tajikistan
Tajikistan (, ; tg, Тоҷикистон, Tojikiston; russian: Таджикистан, Tadzhikistan), officially the Republic of Tajikistan ( tg, Ҷумҳурии Тоҷикистон, Jumhurii Tojikiston), is a landlocked country in Centr ...
. One bird was found in the Baikka Wetland in
Srimangal
Sreemangal ( bn, শ্রীমঙ্গল, Srimongol) is an upazila of Moulvibazar District in the Sylhet Division of Bangladesh. It is located at the southwest of the district, and borders the Habiganj District to the west and the Indian state ...
,
Bangladesh
Bangladesh (}, ), officially the People's Republic of Bangladesh, is a country in South Asia. It is the eighth-most populous country in the world, with a population exceeding 165 million people in an area of . Bangladesh is among the mos ...
on 7 December 2011.
["Rare Bird in Baikka Wetland", Daily Prothom Alo](_blank)
Description
This species has the upper plumage and visible portions of wings and tail olive-brown while the underside is pale creamy with the underwing and axillaries paler.
The length is about with the tail being and the wing long. The tarsus is while the bill from
gape
The beak, bill, or rostrum is an external anatomical structure found mostly in birds, but also in turtles, non-avian dinosaurs and a few mammals. A beak is used for eating, preening, manipulating objects, killing prey, fighting, probing for food, ...
is . The first primary measures while the second is intermediate in length between the ninth and tenth. The closed tail appears graduated with the difference between the longest and shortest feathers being . The type specimen was obtained in the
Sutlej
The Sutlej or Satluj River () is the longest of the five rivers that flow through the historic crossroads region of Punjab in northern India and Pakistan. The Sutlej River is also known as ''Satadru''. It is the easternmost tributary of the Ind ...
valley ("Sukedje valley") not far from Rampur.
The upper mandible is dark, but the cutting edges and entire lower mandible are pale. The tarsi, toes and claws appear pale brown. The hind claw is longer than in ''
A. dumetorum''. The tips of the tail feathers are pointed and more acutely lanceolate than in ''
A. dumetorum'' or ''
A. concinens''. The primary tips are broad and rather squarer. Recent observers note that it has a habit of fanning out its tail open as it forages.
The specimens from Afghanistan and Kazakhstan suggest that they breed in Central Asia and moult indicates that they migrate along the Himalayas to winter in northern India and Southeast Asia. Sequence variation points to a stable or shrinking population structure.
History
It was first collected by
Allan Octavian Hume
Allan Octavian Hume, CB ICS (4 June 1829 – 31 July 1912) was a British civil servant, political reformer, ornithologist and botanist who worked in British India. He was the founder of the Indian National Congress. A notable ornithologist, Hum ...
in the
Sutlej Valley
The Sutlej or Satluj River () is the longest of the five rivers that flow through the historic crossroads region of Punjab in northern India and Pakistan. The Sutlej River is also known as ''Satadru''. It is the easternmost tributary of the Ind ...
near Rampur,
Himachal Pradesh
Himachal Pradesh (; ; "Snow-laden Mountain Province") is a state in the northern part of India. Situated in the Western Himalayas, it is one of the thirteen mountain states and is characterized by an extreme landscape featuring several peaks ...
,
India
India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the so ...
on 13 November 1867. This specimen (BMNH registration no. 1886.7.8. 1742) was first provisionally described as ''Phyllopneuste macrorhyncha'' (
Hume, 1869) but the name was changed two years later to ''Acrocephalus macrorhynchus'' (Hume, 1871).
H C Oberholser, however, pointed out in 1905 that this was unacceptable because a specimen from Egypt described by
von Müller in 1853 as ''Calamoherpe macrorhyncha'' turned out to be ''Acrocephalus stentoreus''; ''Acrocephalus macrorhynchus'' was abandoned in favour of ''A. orinus''. The identity of the species was in question and until 2002 was considered as a synonym of the
clamorous reed warbler
The clamorous reed warbler (''Acrocephalus stentoreus'') is an Old World warbler in the genus '' Acrocephalus''. It breeds from Egypt eastwards through Pakistan, Afghanistan and northernmost India to south China and southeast Asia. ''A. s. meridi ...
(''A. stentoreus''). Some others considered it an aberrant Blyth's reed warbler. A recent re-check of the morphology and the
mtDNA
Mitochondrial DNA (mtDNA or mDNA) is the DNA located in mitochondria, cellular organelles within eukaryotic cells that convert chemical energy from food into a form that cells can use, such as adenosine triphosphate (ATP). Mitochondrial DNA ...
suggested that it was a distinct species. An additional ten new specimens in collections were identified in 2008. These included specimens collected by
John Biddulph
Colonel John Biddulph (25 July 1840 – 24 December 1921) was a British soldier, author and naturalist who served in the government of British India.
Biddulph was born in 1840, and was the third son of Robert Biddulph. He was educated at Wes ...
from Gilgit and
W N Koelz from Zebak.
Rediscovery
On 27 March 2006 a living specimen was caught at the
in
Phetchaburi
Phetchaburi ( th, เพชรบุรี, ) or Phet Buri () is a town (''thesaban mueang'') in southern Thailand, capital of Phetchaburi Province. In Thai, Phetchaburi means "city of diamonds" (''buri'' meaning "city" in Sanskrit). It is approx ...
,
Thailand
Thailand ( ), historically known as Siam () and officially the Kingdom of Thailand, is a country in Southeast Asia, located at the centre of the Indochinese Peninsula, spanning , with a population of almost 70 million. The country is bo ...
by ornithologist Philip Round of
Mahidol University
Mahidol University (Mahidol), an autonomous research institution in Thailand, had its origin in the establishment of Siriraj Hospital in 1888. Mahidol had an acceptance rate for Medicine of 0.4% as of the 2016 academic year.
Becoming the Univers ...
. The bird was
ringed and two feathers were extracted; DNA from them was found to match the DNA of the 1867 specimen.
Based on the short and rounded wings, earlier studies had suggested that the species was likely to be a short-distant migrant or a resident. The rediscoveries of a second museum specimen from a different location and the wild specimen from Thailand suggest that this may not be so.
Some field identifications from West Bengal and central India were subsequently reported based on behaviour, but captured specimens did not appear to match the species.
A breeding site of the large-billed reed warbler, ''Acrocephalus orinus'', was discovered in the
Wakhan Corridor
The Wakhan Corridor ( ps, واخان دهلېز, translit=wāxān dahléz, fa, دالان واخان, translit=dâlân vâxân) is a narrow strip of territory in Badakhshan Province of Afghanistan, extending to Xinjiang in China and separatin ...
of the
Pamir Pamir may refer to:
Geographical features
* Pamir Mountains, a mountain range in Central Asia
** Pamir-Alay, a mountain system in Tajikistan, Kyrgyzstan and Uzbekistan, part of the Pamir Mountains
*A pamir (valley) is a high plateau or valley surro ...
of north-eastern
Afghanistan
Afghanistan, officially the Islamic Emirate of Afghanistan,; prs, امارت اسلامی افغانستان is a landlocked country located at the crossroads of Central Asia and South Asia. Referred to as the Heart of Asia, it is bordere ...
by researcher Robert Timmins of the
Wildlife Conservation Society
The Wildlife Conservation Society (WCS) is a non-governmental organization headquartered at the Bronx Zoo in New York City, that aims to conserve the world's largest wild places in 14 priority regions. Founded in 1895 as the New York Zoological ...
, who was studying avian communities in the Pamir Mountains. He came across a small brown warbler and recorded its song. Dr. Timmins did not realize the importance of his discovery until he visited a Natural History Museum in Tring, England. There he examined a specimen of a large-billed reed warbler, which looked identical to the bird he had seen and recorded.
A team of ornithologists, including Afghan scientists of the
Wildlife Conservation Society
The Wildlife Conservation Society (WCS) is a non-governmental organization headquartered at the Bronx Zoo in New York City, that aims to conserve the world's largest wild places in 14 priority regions. Founded in 1895 as the New York Zoological ...
, confirmed his discovery by capturing, sampling and releasing almost 20 specimens of the bird in 2009, the largest number ever recorded, using a combination of field observations, museum specimens, DNA sequencing, and also the first known audio recording of the species that were already made in 2008.
A study by Russian ornithologists in 2011 indicated that the species had been misidentified as ''A. dumetorum'' in museum collections and that the species may be breeding in Tajikistan, Kyrgyzstan, eastern Uzbekistan and south-eastern Kazakhstan. Nests were found in 2011 in the
Panj river
The Panj (russian: Пяндж; fa, رودخانه پنج) (; tg, Панҷ, پنج), traditionally known as the Ochus River and also known as ''Pyandzh'' (derived from its Russian name "Пяндж"), is a tributary of the Amu Darya. The river ...
valley, Tajikistan.
References
External links
Identification notesPhotographsLarge-billed reed warblers incubating clutches, photos by P.V. Kvartalnov
{{Taxonbar, from=Q1359295
large-billed reed warbler
The large-billed reed warbler (''Acrocephalus orinus'') is an Old World warbler in the genus '' Acrocephalus''. The species has been dubbed as "the world's least known bird". It was known from a single specimen collected in India in 1867 and redi ...
Birds of Afghanistan
Birds of Central Asia
Birds of North India
Birds of South Asia
Birds of Southeast Asia
large-billed reed warbler
The large-billed reed warbler (''Acrocephalus orinus'') is an Old World warbler in the genus '' Acrocephalus''. The species has been dubbed as "the world's least known bird". It was known from a single specimen collected in India in 1867 and redi ...
large-billed reed warbler
The large-billed reed warbler (''Acrocephalus orinus'') is an Old World warbler in the genus '' Acrocephalus''. The species has been dubbed as "the world's least known bird". It was known from a single specimen collected in India in 1867 and redi ...
Srimangal Upazila