Jerdon's Babbler
Encyclopedia
Jerdon's Babbler is an endangered passerine bird
from South Asia
. Formerly placed in the Timaliidae family
– hence the common name "babbler" –, the genus
Chrysomma
and its relatives are actually closer to the typical warbler
s and parrotbill
s in the Sylviidae
.
Measuring 16–17 cm in length, it is quite intermediate in habitus
between certain typical warbler
s (Sylvia) and the parrotbill
s (Paradoxornis). Like these, it is a drab bird with a long tail used to balance when creeping through the vegetation; its bill is thicker than in Sylvia but not as heavy as in Paradoxornis. Buff
y chestnut brown above and a slightly lighter yellowish-brown on the belly, its lore
s are pale greyish, as are the throat and breast. The tail and a wing patch are redder than the rest of the upperside. The legs and feet are dark, the bill is greyish-horn colored above and pale below; the eyes' irides
are yellowish-brown and a thin nude ring of greenish-yellow skin surrounds the eye.
The sexes are alike; young birds have a more orange hue to the upperside plumage, and the lower bill is pink. Differences between subspecies
are slight, with the central population essentially have richer chestnut brown and darker grey colours.
Its relative, the Yellow-eyed "Babbler"
(C. sinense), looks like a brighter version of the same but has somewhat more vivid colors, with white replacing grey in the plumage, an additional white supercilium
, yellowish legs, feet and irides, and an orange-yellow eye-ring.
The song is a weak 4- to 8-note warbling chi-chi-chi-chew-chew-chew, tew-tew-tew-tew chew or ih-ih-ih-ih chew chitit chew i'wwiuu, with a drawn-out end note and sometimes starting with a chatter of itch, itit or tchew. Birds sing usually in the early morning and in the evening, perching upright on a reed, with the head slightly elevated. Calls include a short tic or tsik, sometimes extended into a series ts-ts-tsik which may end in a plaintinve tew.
are recognized, based mainly on their allopatric ranges:
1862
s and around oxbow lake
s. Pairs or families of these birds, occasionally small flocks of 1-2 dozen, move about quietly in dense stands of grass
es and reeds
that grow several meters high, usually avoiding lower growth and shrubland. A typical foraging
technique involves perching nearly horizontally
on a reed stem, picking up a leaf sheath with the bill, and quickly tearing off the leaf and its base sheet to expose small arthropod
s and other invertebrate
s. The tearing of dry leaves produces a subdued crackling sound that can sometimes be heard from some dozens of meters away.
Plants dominating its favorite habitat are typically tall reeds several meters in height. C. a. scindicum is usually found in association with Hardy Sugarcane (S. arundinaceum) and Kans Grass
(S. spontaneum), while C. a. griseigularis is also found in Munja (S. munja) stands, and in the east of its range in Ravennagrass (S. ravennae) and perhaps S. procerum. Prime habitat also contains a generous amount of Common Reed (Phragmites australis) or Khagra Reed (P. karka), as well as Typha reedmaces (e.g. Typha angusta). On the other hand, sugarcane plantings or other single-species
reedbeds as well as lower growth are not very attractive to the species. Other plants, typically grass
es, are found to a lesser extent in the bird's haunts. They include such species as satintails (Imperata, e.g. Cogongrass I. cylindrica), Giant Cane (Arundo donax), Vetiver
or khus (Cymbopogon zizanioides), Desmostachya bipinnata
, Narenga porphyrocoma and Themeda arundinacea.
by the IUCN, being nowhere common and at least in Assam
(where it is perhaps most numerous) its numbers are declining. The nominate subspecies from Myanmar
might be extinct already. It was last seen in July 1941 in habitat fragments at Myitkyo, with the last specimen taken in 1914 or perhaps as late as the mid-1930s. Due to the inaccessibility of its range and consequent lack of fieldwork, it might conceivably still exist however. Likewise, the continuing existence of this species
in Bangladesh
is uncertain. The subspecies griseigularis is the only one known to occur in protected area
s, namely the Dibru-Saikhowa, Kaziranga and Manas National Park
s in Assam, and the Chitwan National Park and Sukla Phanta Wildlife Reserve
of Nepal
. Its presence in the latter country was not documented until 1989/1990. Subspecies scindicum is known to be rare and has been declining throughout recent decades. At present, the only place where it is seen fairly often is the Rohri Canal south of Khairpur.
Altogether, less than 10,000 adult birds are believed to remain. Its threat category is VU
A2c+3c+4c. This means that its population has declined by an estimated 30% and is expected to continue to do so for another decade at least. The reasons are not fully understood, but the population reduction is probably related to habitat destruction
by drainage
and damming of wetlands for agriculture and flood control
, and these threats are not expected to cease anytime soon. In 1933 it was stated that to attract the birds there ought to be
but in our time, such habitat is extremely rare.
Sustainable cutting of reedbeds, which yield material for human use, is apparently tolerated by C. altirostre. Large flocks of the species are found in partially cut or burned reedbeds, thus if large-scale clear-cutting is avoided, human use of reeds may in fact improve habitat
quality by preventing the simultaneous aging and decay
of wide stretches of habitat. As a rule-of-thumb, as long as a healthy population of Phragmites
reeds persists, the birds are likely to persist too.
Passerine
A passerine is a bird of the order Passeriformes, which includes more than half of all bird species. Sometimes known as perching birds or, less accurately, as songbirds, the passerines form one of the most diverse terrestrial vertebrate orders: with over 5,000 identified species, it has roughly...
from South Asia
South Asia
South Asia, also known as Southern Asia, is the southern region of the Asian continent, which comprises the sub-Himalayan countries and, for some authorities , also includes the adjoining countries to the west and the east...
. Formerly placed in the Timaliidae family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
– hence the common name "babbler" –, the genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
Chrysomma
Chrysomma
Chrysomma is a songbird genus. Long believed to be Timaliidae , they are actually quite closely related to the typical warblers and even closer to the parrotbills, and therefore a member of the family Sylviidae.Species are:...
and its relatives are actually closer to the typical warbler
Typical warbler
The typical warblers are small birds belonging to the genus Sylvia in the "Old World warbler" family Sylviidae. There are 28 species currently included in the genus, including five species formerly treated in the genus Parisoma, a treatment which left Sylvia paraphyletic...
s and parrotbill
Parrotbill
The parrotbills are a group of peculiar birds native to East and Southeast Asia, though feral populations are known from elsewhere. They are generally small, long-tailed birds which inhabit reedbeds and similar habitat. They feed mainly on seeds, e.g. of grasses, to which their bill, as the name...
s in the Sylviidae
Sylviidae
Sylviidae is a family of passerine birds that was part of an assemblage known as the Old World warblers. The family was formerly a wastebin taxon with over 400 species of bird in over 70 genera. The family was poorly defined with many characteristics shared with other families...
.
Description
Morphology (biology)
In biology, morphology is a branch of bioscience dealing with the study of the form and structure of organisms and their specific structural features....
between certain typical warbler
Typical warbler
The typical warblers are small birds belonging to the genus Sylvia in the "Old World warbler" family Sylviidae. There are 28 species currently included in the genus, including five species formerly treated in the genus Parisoma, a treatment which left Sylvia paraphyletic...
s (Sylvia) and the parrotbill
Parrotbill
The parrotbills are a group of peculiar birds native to East and Southeast Asia, though feral populations are known from elsewhere. They are generally small, long-tailed birds which inhabit reedbeds and similar habitat. They feed mainly on seeds, e.g. of grasses, to which their bill, as the name...
s (Paradoxornis). Like these, it is a drab bird with a long tail used to balance when creeping through the vegetation; its bill is thicker than in Sylvia but not as heavy as in Paradoxornis. Buff
Buff (colour)
Buff is a pale yellow-brown colour that got its name from the colour of buff leather.Displayed on the right is the colour buff.EtymologyAccording to the Oxford English Dictionary, buff as a descriptor of a colour was first used in the London Gazette of 1686, describing a uniform to be "A Red Coat...
y chestnut brown above and a slightly lighter yellowish-brown on the belly, its lore
Lore (anatomy)
The Lore is the region between the eye and bill on the side of a bird's head. This region is sometimes featherless, and the skin may be tinted, as in many species of the cormorant family. This area, which is directly in front of the eye, features a "loral stripe" in many bird species including the...
s are pale greyish, as are the throat and breast. The tail and a wing patch are redder than the rest of the upperside. The legs and feet are dark, the bill is greyish-horn colored above and pale below; the eyes' irides
Iris (anatomy)
The iris is a thin, circular structure in the eye, responsible for controlling the diameter and size of the pupils and thus the amount of light reaching the retina. "Eye color" is the color of the iris, which can be green, blue, or brown. In some cases it can be hazel , grey, violet, or even pink...
are yellowish-brown and a thin nude ring of greenish-yellow skin surrounds the eye.
The sexes are alike; young birds have a more orange hue to the upperside plumage, and the lower bill is pink. Differences between subspecies
Subspecies
Subspecies in biological classification, is either a taxonomic rank subordinate to species, ora taxonomic unit in that rank . A subspecies cannot be recognized in isolation: a species will either be recognized as having no subspecies at all or two or more, never just one...
are slight, with the central population essentially have richer chestnut brown and darker grey colours.
Its relative, the Yellow-eyed "Babbler"
Yellow-eyed Babbler
The Yellow-eyed Babbler Chrysomma sinense is a passerine bird species found in open grass and scrub in south Asia. Its common name refers to its traditional placement with the Old World babbler family Timaliidae...
(C. sinense), looks like a brighter version of the same but has somewhat more vivid colors, with white replacing grey in the plumage, an additional white supercilium
Supercilium
The supercilium is a plumage feature found on the heads of some bird species. It is a stripe which runs from the base of the bird's beak above its eye, finishing somewhere towards the rear of the bird's head. Also known as an "eyebrow", it is distinct from the eyestripe, which is a line which runs...
, yellowish legs, feet and irides, and an orange-yellow eye-ring.
The song is a weak 4- to 8-note warbling chi-chi-chi-chew-chew-chew, tew-tew-tew-tew chew or ih-ih-ih-ih chew chitit chew i'wwiuu, with a drawn-out end note and sometimes starting with a chatter of itch, itit or tchew. Birds sing usually in the early morning and in the evening, perching upright on a reed, with the head slightly elevated. Calls include a short tic or tsik, sometimes extended into a series ts-ts-tsik which may end in a plaintinve tew.
Subspecies and range
Three subspeciesSubspecies
Subspecies in biological classification, is either a taxonomic rank subordinate to species, ora taxonomic unit in that rank . A subspecies cannot be recognized in isolation: a species will either be recognized as having no subspecies at all or two or more, never just one...
are recognized, based mainly on their allopatric ranges:
Myanmar Jerdon's "Babbler
Chrysomma altirostre altirostre JerdonThomas C. Jerdon
Thomas Caverhill Jerdon was a British physician, zoologist and botanist. He is best remembered for his pioneering works on the ornithology of India...
1862
- Described above.
- FloodplainFloodplainA floodplain, or flood plain, is a flat or nearly flat land adjacent a stream or river that stretches from the banks of its channel to the base of the enclosing valley walls and experiences flooding during periods of high discharge...
s of the Irrawaddy River from BhamoBhamoBhamo is a city of Kachin State in northernmost part of Myanmar, located 186 km south from the capital city of Myitkyina. It is on the Ayeyarwady River. It lies within 65 km of the border with Yunnan Province, China. The population consists of Chinese and Shan, with Kachin peoples in...
to BagoBago, MyanmarBago ; , ; Pha-Kho พะโค; formerly Pegu, is a city and the capital of Bago Division in Myanmar . It is located from Yangon.-History:...
and up the Sittaung River nearly to TaungooTaungoo-Administration:*Taungoo District Peace and Development Council - List of Six Townships*Taungoo Township Peace and Development Council*Taungoo Ward Peace and Development Council - 22 Wards*Taungoo Municipal*District and Township Immigration Dept...
in MyanmarMyanmarBurma , officially the Republic of the Union of Myanmar , is a country in Southeast Asia. Burma is bordered by China on the northeast, Laos on the east, Thailand on the southeast, Bangladesh on the west, India on the northwest, the Bay of Bengal to the southwest, and the Andaman Sea on the south....
. Possibly extinct. The type specimen of the nominate subspecies – and thus the entire species – was collected on an island in the Ayeyarwady off ThayetmyoThayetmyoThayet or Thayetmyo is a city in Thayet District of Magway Region in central Burma . It is a port on the right bank of the Irrawaddy River, across and just south of Allanmyo, between Pyay and Magway. Thayet is the administrative seat of both Thayet District and Thayet Township...
.
Terai Jerdon's Babbler
Chrysomma altirostre griseigularis- Darker and richer in colour overall, more reddish above, lores blackish. Stronger grey hue on throat and breast.
- Sub-Himalayan TeraiTeraiThe Terai is a belt of marshy grasslands, savannas, and forests located south of the outer foothills of the Himalaya, the Siwalik Hills, and north of the Indo-Gangetic Plain of the Ganges, Brahmaputra and their tributaries. The Terai belongs to the Terai-Duar savanna and grasslands ecoregion...
, from western NepalNepalNepal , officially the Federal Democratic Republic of Nepal, is a landlocked sovereign state located in South Asia. It is located in the Himalayas and bordered to the north by the People's Republic of China, and to the south, east, and west by the Republic of India...
and perhaps BhutanBhutanBhutan , officially the Kingdom of Bhutan, is a landlocked state in South Asia, located at the eastern end of the Himalayas and bordered to the south, east and west by the Republic of India and to the north by the People's Republic of China...
to the Dooars and Brahmaputra floodplain of IndiaIndiaIndia , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...
, Cachar and the Naga HillsNaga hillsNaga hills, reaching a height of around 3825 metres, lie on the border of India and Burma . These hills are part of a complex mountain system, and the parts of the mountain ranges inside the Indian state of Nagaland and the Burmese region of Sagaing are called the Naga Hills.In British India, the...
; possibly also the Surma RiverSurma RiverThe Surma River is a major river in Bangladesh, part of the Surma-Meghna River System. It starts when the Barak River from northeast India divides at the Bangladesh border into the Surma and the Kushiyara rivers. It ends in Kishoreganj District, above Bhairab Bazar, where the two rivers rejoin to...
valley and HaorHaorA haor is a wetland ecosystem in the north eastern part of Bangladesh which physically is a bowl or saucer shaped shallow depression, also known as a backswamp...
basin in BangladeshBangladeshBangladesh , officially the People's Republic of Bangladesh is a sovereign state located in South Asia. It is bordered by India on all sides except for a small border with Burma to the far southeast and by the Bay of Bengal to the south...
, where it used to occur. A NHMNatural History MuseumThe Natural History Museum is one of three large museums on Exhibition Road, South Kensington, London, England . Its main frontage is on Cromwell Road...
specimen is supposedly from Bhamo in the Kachin StateKachin StateKachin State , is the northernmost state of Burma. It is bordered by China to the north and east; Shan State to the south; and Sagaing Division and India to the west. It lies between north latitude 23° 27' and 28° 25' longitude 96° 0' and 98° 44'. The area of Kachin State is . The capital of the...
of Myanmar, but may just as well be mislabelled. - The Sukla Phanta Wildlife ReserveSukla Phanta Wildlife ReserveSukla Phanta Wildlife Reserve is a protected area in the Terai of the Far-Western Region, Nepal, covering of open grassland, forests, riverbeds and tropical wetlands at an altitude of . It was gazetted in 1973 as Royal Sukla Phanta Wildlife Reserve...
in NepalNepalNepal , officially the Federal Democratic Republic of Nepal, is a landlocked sovereign state located in South Asia. It is located in the Himalayas and bordered to the north by the People's Republic of China, and to the south, east, and west by the Republic of India...
represents the western limit of its distribution.
Sind Jerdon's Babbler
Chrysomma altirostre scindicum- Resembles altirostre.
- Indus basinDrainage basinA drainage basin is an extent or an area of land where surface water from rain and melting snow or ice converges to a single point, usually the exit of the basin, where the waters join another waterbody, such as a river, lake, reservoir, estuary, wetland, sea, or ocean...
of PakistanPakistanPakistan , officially the Islamic Republic of Pakistan is a sovereign state in South Asia. It has a coastline along the Arabian Sea and the Gulf of Oman in the south and is bordered by Afghanistan and Iran in the west, India in the east and China in the far northeast. In the north, Tajikistan...
, where recorded from a few disjunctDisjunctThe term disjunct can refer to:* disjunct * disjunct or quincunx in astrology, an aspect made when two planets are 150 degrees, or five signs apart...
areas: - SangharSanghar DistrictSanghar District is one of the largest districts of Sindh province, Pakistan. It is located in the centre of Sindh and is bounded to the east by India. The district capital, Sanghar, is itself a small city roughly east-south-east of the city of Nawabshah and the same distance north of Mirpur...
, TharparkarTharparkar DistrictTharparkar District is one of twenty three districts of Sindh province in Pakistan. It is headquarters is at Mithi. It has the lowest Human Development Index of all districts in Sindh.-Demography:...
and Umerkot DistrictUmerkot DistrictUmerkot District or Umarkot District is a district of Sindh province, Pakistan.-History:After the 1843 invasion by Charles Napier, Sindh was divided into provinces and was assigned a Zamindars, also known as Wadaras, to collect taxes for the British....
s of SE SindhSindhSindh historically referred to as Ba'ab-ul-Islam , is one of the four provinces of Pakistan and historically is home to the Sindhi people. It is also locally known as the "Mehran". Though Muslims form the largest religious group in Sindh, a good number of Christians, Zoroastrians and Hindus can...
Province. Population possibly extinct. - DaduDadu DistrictDadu is a district of Sindh Province, Pakistan.Dadu district was created in 1933 by the British Indian administration by merging Kotri and Kohistan tehsils from Karachi district and Mehar, Khairpur Nathan Shah, Dadu, Johi and Sehwan tehsils from Larkana district. The population of the district is...
, KhairpurKhairpur DistrictKhairpur District is a district in the Sindh province of Pakistan. The district has an area of 15,910 square kilometres and is headquartered at the city of Khairpur.-Location:...
, LarkanaLarkana DistrictLarkana or Larkano is a district of Sindh province of Pakistan. According to the 1998 census of Pakistan, it had a population of 1,927,066 of which 28.70% were urban. Its main city is Larkana...
, Shaheed Benazeerabad District, ShikarpurShikarpur DistrictShikarpur district is a district in the Sindh province of Pakistan. The city of Shikarpur is the capital. It is spread over an area of 2,512 km2, according to the 1998 census of Pakistan it had a population of 880,438 of which 23.51% were urban....
and Sukkur DistrictSukkur DistrictSukkur district is a district in Sindh Province in Pakistan. It is divided into 4 administrative strata , namely; Sukkur City, Rohri, Saleh Pat and Pano Aqil. Among them Sukkur city and new Sukkur are urban centre while Pano Aqil is famous for having one of largest military cantonment of the country...
s of NC Sindh Province, approximately from SukkurSukkurSukkur, or Sakharu , formerly Aror and Bakar, is the third largest city of Sindh province, situated on the west bank of Indus River in Pakistan in Sukkur District. However, the word Sakharu in Sindhi means "superior", which the spelling of the city's name in Sindhi suggests is the origin of the...
(where the type specimen of scindicum was collected) to NawabshahNawabshahNawabshah , or Shaheed Benazirabad, is a district in the Sindh province of Pakistan. It is headquarter of Shaheed Benazir Abad District...
. - Dera Ghazi KhanDera Ghazi Khan DistrictDera Ghazi Khan is a district in the Punjab province of Pakistan. The district covers an area of 5,306 m² and it is a long narrow strip of country, 198 m...
, Dera Ismail KhanDera Ismail Khan DistrictDera Ismail Khan is one of the 24 districts in the Khyber Pakhtunkhwa province of Pakistan. The capital of the district is the town of Dera Ismail Khan...
, MianwaliMianwali DistrictMianwali is a district in the northwest of Punjab province, Pakistan. It borders eight districts: Attock District in the north, Chakwal District in the northeast, Khushab District in the east, and Bhakkar District in the south, while Lakki Marwat lies to the west, Kohat and Karak districts to the...
and Muzaffargarh DistrictMuzaffargarh DistrictMuzaffargarh is a district in the south of the Punjab province of Pakistan. It is part of Saraiki Waseb. It is spread over an area of 8,249 km². Muzaffargarh District lies in the strip between the rivers Chenab and Indus, which pass along the Eastern and Western boundaries respectively of...
s between S North-West Frontier and SW PunjabPunjab (Pakistan)Punjab is the most populous province of Pakistan, with approximately 45% of the country's total population. Forming most of the Punjab region, the province is bordered by Kashmir to the north-east, the Indian states of Punjab and Rajasthan to the east, the Pakistani province of Sindh to the...
Provinces. Old records specifically from near Bhamb, JampurJampurJampur is a small city located at 29°38'32" N , 70°35'45"E in Rajanpur District, south of Dera Ghazi Khan, in the centre of Pakistan. It comprises an area of about 8-10 square kilometres and has a population of almost 1,20,000.-History:...
and Khanwah. Recent records exist from the Dera Ismail KhanDera Ismail KhanDera Ismail Khan is a city in Khyber-Pakhtunkhwa Province, Pakistan. It is situated on the west bank of the Indus River, west of Lahore and northwest of Multan. The city is the capital of the district and tehsil of the same name. In Pakistan, its name is often abbreviated to D. I...
area, Dhap ShumaliDhap ShumaliDhap Shumali is a town and union council in Dera Ismail Khan District of Khyber-Pakhtunkhwa....
, Taunsa BarrageTaunsa BarrageTaunsa Barrage is a barrage on the River Indus in the Muzaffargarh District of Punjab province of Pakistan. It is situated 20 km southeast of Taunsa Sharif....
and Chashma Barrage (the northernmost known site for this subspecies)
Ecology
It is presumably an all-year resident and inhabits dense growth near water, often in the floodplainFloodplain
A floodplain, or flood plain, is a flat or nearly flat land adjacent a stream or river that stretches from the banks of its channel to the base of the enclosing valley walls and experiences flooding during periods of high discharge...
s and around oxbow lake
Oxbow lake
An oxbow lake is a U-shaped body of water formed when a wide meander from the main stem of a river is cut off to create a lake. This landform is called an oxbow lake for the distinctive curved shape, named after part of a yoke for oxen. In Australia, an oxbow lake is called a billabong, derived...
s. Pairs or families of these birds, occasionally small flocks of 1-2 dozen, move about quietly in dense stands of grass
Grass
Grasses, or more technically graminoids, are monocotyledonous, usually herbaceous plants with narrow leaves growing from the base. They include the "true grasses", of the Poaceae family, as well as the sedges and the rushes . The true grasses include cereals, bamboo and the grasses of lawns ...
es and reeds
Reed bed
Reed beds are natural habitats found in floodplains, waterlogged depressions andestuaries. Reed beds are part of a succession from young reed colonising open water or wet ground through a gradation of increasingly dry ground...
that grow several meters high, usually avoiding lower growth and shrubland. A typical foraging
Foraging
- Definitions and significance of foraging behavior :Foraging is the act of searching for and exploiting food resources. It affects an animal's fitness because it plays an important role in an animal's ability to survive and reproduce...
technique involves perching nearly horizontally
Horizontal plane
In geometry, physics, astronomy, geography, and related sciences, a plane is said to be horizontal at a given point if it is perpendicular to the gradient of the gravity field at that point— in other words, if apparent gravity makes a plumb bob hang perpendicular to the plane at that point.In...
on a reed stem, picking up a leaf sheath with the bill, and quickly tearing off the leaf and its base sheet to expose small arthropod
Arthropod
An arthropod is an invertebrate animal having an exoskeleton , a segmented body, and jointed appendages. Arthropods are members of the phylum Arthropoda , and include the insects, arachnids, crustaceans, and others...
s and other invertebrate
Invertebrate
An invertebrate is an animal without a backbone. The group includes 97% of all animal species – all animals except those in the chordate subphylum Vertebrata .Invertebrates form a paraphyletic group...
s. The tearing of dry leaves produces a subdued crackling sound that can sometimes be heard from some dozens of meters away.
Plants dominating its favorite habitat are typically tall reeds several meters in height. C. a. scindicum is usually found in association with Hardy Sugarcane (S. arundinaceum) and Kans Grass
Kans grass
Kans grass is a grass native to South Asia. It is a perennial grass, growing up to three meters in height, with spreading rhizomatous roots....
(S. spontaneum), while C. a. griseigularis is also found in Munja (S. munja) stands, and in the east of its range in Ravennagrass (S. ravennae) and perhaps S. procerum. Prime habitat also contains a generous amount of Common Reed (Phragmites australis) or Khagra Reed (P. karka), as well as Typha reedmaces (e.g. Typha angusta). On the other hand, sugarcane plantings or other single-species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
reedbeds as well as lower growth are not very attractive to the species. Other plants, typically grass
Grass
Grasses, or more technically graminoids, are monocotyledonous, usually herbaceous plants with narrow leaves growing from the base. They include the "true grasses", of the Poaceae family, as well as the sedges and the rushes . The true grasses include cereals, bamboo and the grasses of lawns ...
es, are found to a lesser extent in the bird's haunts. They include such species as satintails (Imperata, e.g. Cogongrass I. cylindrica), Giant Cane (Arundo donax), Vetiver
Vetiver
Chrysopogon zizanioides, commonly known as vetiver , is a perennial grass of the Poaceae family, native to India. In western and northern India, it is popularly known as khus. Vetiver can grow up to 1.5 metres high and form clumps as wide. The stems are tall and the leaves are long, thin, and...
or khus (Cymbopogon zizanioides), Desmostachya bipinnata
Desmostachya bipinnata
Desmostachya bipinnata, commonly known in English by the names Halfa grass, Big cordgrass, and Salt reed-grass, is an Old World perennial grass, long known and used in human history...
, Narenga porphyrocoma and Themeda arundinacea.
Conservation status
It is classified as VulnerableVulnerable species
On 30 January 2010, the IUCN Red List of Threatened Species identified 9694 Vulnerable species, subspecies and varieties, stocks and sub-populations.-References:...
by the IUCN, being nowhere common and at least in Assam
Assam
Assam , also, rarely, Assam Valley and formerly the Assam Province , is a northeastern state of India and is one of the most culturally and geographically distinct regions of the country...
(where it is perhaps most numerous) its numbers are declining. The nominate subspecies from Myanmar
Myanmar
Burma , officially the Republic of the Union of Myanmar , is a country in Southeast Asia. Burma is bordered by China on the northeast, Laos on the east, Thailand on the southeast, Bangladesh on the west, India on the northwest, the Bay of Bengal to the southwest, and the Andaman Sea on the south....
might be extinct already. It was last seen in July 1941 in habitat fragments at Myitkyo, with the last specimen taken in 1914 or perhaps as late as the mid-1930s. Due to the inaccessibility of its range and consequent lack of fieldwork, it might conceivably still exist however. Likewise, the continuing existence of this species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
in Bangladesh
Bangladesh
Bangladesh , officially the People's Republic of Bangladesh is a sovereign state located in South Asia. It is bordered by India on all sides except for a small border with Burma to the far southeast and by the Bay of Bengal to the south...
is uncertain. The subspecies griseigularis is the only one known to occur in protected area
Protected area
Protected areas are locations which receive protection because of their recognised natural, ecological and/or cultural values. There are several kinds of protected areas, which vary by level of protection depending on the enabling laws of each country or the regulations of the international...
s, namely the Dibru-Saikhowa, Kaziranga and Manas National Park
Manas National Park
Manas National Park or Manas Wildlife Sanctuary is a Wildlife Sanctuary, UNESCO Natural World Heritage site, a Project Tiger Reserve, an Elephant Reserve and a Biosphere Reserve in Assam, India. Located in the Himalayan foothills, it is contiguous with the Royal Manas National park in Bhutan...
s in Assam, and the Chitwan National Park and Sukla Phanta Wildlife Reserve
Sukla Phanta Wildlife Reserve
Sukla Phanta Wildlife Reserve is a protected area in the Terai of the Far-Western Region, Nepal, covering of open grassland, forests, riverbeds and tropical wetlands at an altitude of . It was gazetted in 1973 as Royal Sukla Phanta Wildlife Reserve...
of Nepal
Nepal
Nepal , officially the Federal Democratic Republic of Nepal, is a landlocked sovereign state located in South Asia. It is located in the Himalayas and bordered to the north by the People's Republic of China, and to the south, east, and west by the Republic of India...
. Its presence in the latter country was not documented until 1989/1990. Subspecies scindicum is known to be rare and has been declining throughout recent decades. At present, the only place where it is seen fairly often is the Rohri Canal south of Khairpur.
Altogether, less than 10,000 adult birds are believed to remain. Its threat category is VU
Vulnerable species
On 30 January 2010, the IUCN Red List of Threatened Species identified 9694 Vulnerable species, subspecies and varieties, stocks and sub-populations.-References:...
A2c+3c+4c. This means that its population has declined by an estimated 30% and is expected to continue to do so for another decade at least. The reasons are not fully understood, but the population reduction is probably related to habitat destruction
Habitat destruction
Habitat destruction is the process in which natural habitat is rendered functionally unable to support the species present. In this process, the organisms that previously used the site are displaced or destroyed, reducing biodiversity. Habitat destruction by human activity mainly for the purpose of...
by drainage
Drainage
Drainage is the natural or artificial removal of surface and sub-surface water from an area. Many agricultural soils need drainage to improve production or to manage water supplies.-Early history:...
and damming of wetlands for agriculture and flood control
Flood control
In communications, flood control is a feature of many communication protocols designed to prevent overwhelming of a destination receiver. Such controls can be implemented either in software or in hardware, and will often request that the message be resent after the receiver has finished...
, and these threats are not expected to cease anytime soon. In 1933 it was stated that to attract the birds there ought to be
"... a regular 'sea of sugarcaneSugarcaneSugarcane refers to any of six to 37 species of tall perennial grasses of the genus Saccharum . Native to the warm temperate to tropical regions of South Asia, they have stout, jointed, fibrous stalks that are rich in sugar, and measure two to six metres tall...
', preferably not less than six feet high."
but in our time, such habitat is extremely rare.
Sustainable cutting of reedbeds, which yield material for human use, is apparently tolerated by C. altirostre. Large flocks of the species are found in partially cut or burned reedbeds, thus if large-scale clear-cutting is avoided, human use of reeds may in fact improve habitat
Habitat
* Habitat , a place where a species lives and grows*Human habitat, a place where humans live, work or play** Space habitat, a space station intended as a permanent settlement...
quality by preventing the simultaneous aging and decay
Ecological succession
Ecological succession, is the phenomenon or process by which a community progressively transforms itself until a stable community is formed. It is a fundamental concept in ecology, and refers to more or less predictable and orderly changes in the composition or structure of an ecological community...
of wide stretches of habitat. As a rule-of-thumb, as long as a healthy population of Phragmites
Phragmites
Phragmites, the Common reed, is a large perennial grass found in wetlands throughout temperate and tropical regions of the world. Phragmites australis is sometimes regarded as the sole species of the genus Phragmites, though some botanists divide Phragmites australis into three or four species...
reeds persists, the birds are likely to persist too.