|Female with yellow iris|
The black-necked stork (Ephippiorhynchus asiaticus) is a tall long-necked wading bird in the stork family. It is a resident species across South and Southeast Asia with a disjunct population in Australia. It lives in wetland habitats where it forages for a wide range of animal prey. Adult birds of both sexes have a heavy bill and are patterned in white and glossy blacks, but the sexes differ in the colour of the iris. In Australia, it is sometimes called a jabiru although that name refers to a stork species found in the Americas. It is one of the few storks that is strongly territorial when feeding.
The black-necked stork is a large bird, 129–150 cm (51–60 inches) tall having a 230-cm (91-inch) wingspan. The average weight is around 4,100 grams. The plumage patterns are conspicuous with younger birds differing from adults. Adults have a glossy bluish-black iridescent head, neck, secondary flight feathers and tail; a coppery-brown crown; a bright white back and belly; bill black with a slightly concave upper edge; and bright red legs. The sexes are identical but the adult female has a yellow iris while the adult male has it brown. Juveniles younger than six months have a brownish iris; a distinctly smaller and straighter beak; a fluffy appearance; brown head, neck, upper back, wings and tail; a white belly; and dark legs. Juveniles older than six months have a mottled appearance especially on the head and neck where the iridescence is partly developed; dark-brown outer primaries; white inner primaries that forms a shoulder patch when the wings are closed; a heavy beak identical in size to adults but still straighter; and dark to pale-pink legs. Like most storks, the black-necked stork flies with the neck outstretched, not retracted like a heron. In flight it appears spindly and a black bar running through the white wings (the somewhat similar looking migratory black stork has an all black wing) with black neck and tail make it distinctive.
Taxonomy and systematics
First described by John Latham as Mycteria asiatica, this species was later placed in the genus Xenorhynchus based on morphology. Based on behavioural similarities, Kahl suggested the placement of the species in the genus Ephippiorhynchus, which then included a single species, the saddle-billed stork. This placement of both the black-necked stork and saddle-billed stork under the same genera was later supported by osteological and behavioural data, and DNA-DNA hybridisation and cytochrome – b data. The genera Xenorhynchus and Ephippiorhynchus were both erected at the same time, and as first revisor, Kahl selected the latter as the valid genus for the two species. This and the saddle-billed stork Ephippiorhynchus senegalensis are the only stork species that show marked sexual dimorphism in iris colour.
Two subspecies are recognized E. a. asiaticus of the Oriental region and E. a. australis of south New Guinea and Australia. Charles Lucien Bonaparte erected the genus Xenorhynchus in 1855 and placed two species in it, X. indica and X. australis. This treatment was carried on into later works. James Lee Peters in his 1931 work treated them as subspecies. In 1989, McAllan and Bruce again suggested the elevation of the two subspecies into two species: E. asiaticus or the green-necked stork of the Oriental region, and E. australis or the black-necked stork of the Australian and New Guinean region. This recommendation was based on the disjunct distributions and differences in the iridescent colouration of the neck which the authors suggested might reflect different behavioural displays. This recommendation has not been followed and a subsequent study did not find consistent differences in the colours. Analysis of the cytochrome b mitochondrial sequences however showed significant genetic divergence. The genetic distance of a stork presumed to be Ephippiorhynchus asiaticus asiaticus from a confirmed individual of E. a. australis was 2.1%, much greater than the genetic distances between individual storks of the same species. The conservative treatment as two subspecies has been followed in the Australian faunal list by Christidis and Boles.
Distribution and habitat
In India, it is widespread in the west, central highlands, and northern Gangetic plains into the Assam valley, but somewhat rare in peninsular India and Sri Lanka. This distinctive stork is an occasional straggler in southern and eastern Pakistan. It extends into Southeast Asia, through New Guinea and into the northern half of Australia. Compared to other large waterbirds like cranes, spoonbills and other species of storks, black-necked storks are least abundant in locations with a high diversity of waterbird species.
The largest population of this species occurs in Australia, where it is found from the Ashburton River, near Onslow, Western Australia, across northern Australia to north-east New South Wales. It extends inland in the Kimberley area to south of Halls Creek; in the Northern Territory to Hooker Creek and Daly Waters; and in Queensland inland to the Boulia area and the New South Wales border, with some records as far south as the north-west plains of New South Wales, along the coast of Sydney and formerly bred near the Shoalhaven River. It is rare along the south-east extremity of its range, but common throughout the north. An estimated 1800 occur in the Alligator Rivers region of the Northern Territory, with overall numbers during surveys being low in all seasons.
The largest known breeding population occurs in the largely cultivated landscape of south-western Uttar Pradesh in India. Densities of about 0.099 birds per square kilometre have been estimated in this region made up of a mosaic of cultivated fields and wetlands. About six pairs were found to use the 29 square kilometres of the Keoladeo National Park.
In Sri Lanka, the species is a rare breeding resident, with 4–8 breeding pairs in Ruhuna National Park. It is exceedingly rare, and possibly extinct as a breeding bird, in Bangladesh and Thailand.
Black-necked storks forage in a variety of natural and artificial wetland habitats. They frequently use freshwater, natural wetland habitats such as lakes, ponds, marshes, flooded grasslands, oxbow lakes, swamps, rivers and water meadows. Freshwater, artificial wetland habitats used by these storks include flooded fallow and paddy fields, wet wheat fields, irrigation storage ponds and canals, sewage ponds, and dry floodplains. In cultivated areas, they prefer natural wetlands to forage in, though flooded rice paddies are preferentially used during the monsoon, likely due to excessive flooding of lakes and ponds. Nests are usually on trees that are located in secluded parts of large marshes or in cultivated fields as in India.
Behaviour and ecology
This large stork has a dance-like display. A pair stalk up to each other face to face, extending their wings and fluttering the wing tips rapidly and advancing their heads until the meet. They then clatter their bills and walk away. The display lasts for a minute and may be repeated several times.
Nest building in India commences during the peak of the monsoon with most of the nests initiated during September – November, with few new nests built afterwards until January. They nest in large and isolated trees on which they build a platform. The nest is large, as much as 3 to 6 feet across and made up of sticks, branches and lined with rushes, water-plants and sometimes with a mud plaster on the edges. Nests may be reused year after year. The usual clutch is four eggs which are dull white in colour and broad oval in shape, but varies from one to five eggs. The exact incubation period is not known but is expected to be about 30 days. The chicks hatch with white down which is replaced by a darker grey down on the neck within a week. The scapular feathers emerge first followed by the primaries. The young birds make a chack sound followed by a repeated wee-wee-wee calls. Adult birds take turns at the nest and when one returns to relieve the other, they perform a greeting display with open wings and an up and down movement of the head. Food is brought for the young chicks by the adults and regurgitated onto the nest platform. Adults stop feeding the young at the nest and begin to show aggression towards the chicks after they are about 3 or 4 months old. The young birds may stay on nearby for about a year but disperse soon. Typically one to three chicks fledge from successful nests, but up to four chicks fledge in years with high rainfall. The number of stork pairs that succeed in raising chicks, and the average size of fledged broods, are related to monsoonal and post-monsoon rainfall, improving in years with higher rainfall.
At the nest trees, which are typically tall with large boles and a wide-canopy, the birds in Bharatpur were found to compete with Indian white-backed vultures sometimes failing to nest due to them. While many wetland birds are flushed by birds of prey, these storks are not usually intimidated and can be quite aggressive to other large water-birds such as herons and cranes. Adults aggressively defend small depressions of deep water against egrets and herons (at Malabanjbanjdju in Kakadu National Park, Australia), and drying wetland patches against waterbirds such as spoonbills and woolly-necked storks (at Dudhwa National Park, Uttar Pradesh, India).
The black-necked stork is a carnivore and its diet includes water-birds such as coots, little grebes, northern shoveller, pheasant-tailed jacana, and a range of aquatic vertebrates including fish, amphibians, reptiles and invertebrates such as crabs and molluscs. They have also been known to prey on the eggs and hatchlings of turtles. In the Chambal River valley they have been observed to locate nests of Kachuga dhongoka buried under sand (presumably by moistness of the freshly covered nest) and prey on the eggs of the turtle. In Australia, they have been seen foraging at night feeding on emerging nestlings of marine turtles. Stomach content analyses of nine storks in Australia showed their diet to contain crabs, molluscs, insects (grasshoppers and beetles), amphibians, reptiles and birds. The storks had also consumed a small piece of plastic, pebbles, cattle dung, and plant material. In well-protected wetlands, both in Australia and India, Black-necked storks feed almost exclusively on fish but in the agriculturally dominated wetlands of India they feed on a wider range of prey that include frogs and molluscs; storks obtained fish in wetlands, frogs from roadside ditches and molluscs from irrigation canals.
They sometimes soar in the heat of the day or rest on their hocks. When disturbed, they may stretch out their necks. Their drinking behaviour involves bending down with open bill and scooping up water with a forward motion followed by raising the bill to swallow water. They sometimes carry water in their bill to chicks at the nest or even during nest building or egg stages.
Like other storks, they are very silent except at nest where they make bill-clattering sounds. The sounds produced are of a low-pitch and resonant and ends with a short sigh. Juveniles fledged from the nests can occasionally call using a mildly-warbling, high-pitched series of whistles, usually accompanied with open, quivering wings. These calls and behaviour are directed at adult birds and are a display to solicit food, particularly in drought years when younger birds are apparently unable to find food on their own easily.
Black-necked storks are largely non-social and are usually seen as single birds, pairs and family groups. Flocks of up to 15 storks have been observed in Australia and India, and appear to form due to local habitat conditions such as drying out of wetlands.
Status and conservation
The black-necked stork is widely scattered and nowhere found in high densities, making it difficult for populations to be reliably estimated. The Sri Lankan population has been estimated to be about 50 birds while the species has become very rare in Thailand, Myanmar, Laos and Cambodia. The may have become extinct in the Sundaic region. The combined South and Southeast Asian population is placed at less than 1000 birds. A 2011 study found the population in south-western Uttar Pradesh to be stable, although population growth rates may decline with an increase in the number of dry years or land use changes that that permanently remove the number of breeding pairs. The Australian population has been optimistically estimated at about 20,000 birds while a more conservative estimate suggests about 10,000 birds. They are threatened by habitat destruction, the draining of shallow wetlands, overfishing, pollution, collision with electricity wires and hunting. Exceedingly few breeding populations with high breeding success are known. It is evaluated as Near Threatened on the IUCN Red List.
The Mir Shikars, traditional bird hunters of Bihar, India had a ritual practice that required a young man to capture a black-necked stork "Loha Sarang" alive before he could marry. A procession would locate a bird and the bridegroom-to-be would try to catch the bird with a limed stick. The cornered bird was a ferocious adversary. The ritual was stopped in the 1920s after a young man was killed in the process. Young birds have been known to be taken from the nest for meat in Assam.
In Australia, an aboriginal creation myth describes the origin of the bill of the "jabiru" from a spear that went through the head of a bird. The Binbinga people often consider the meat of the bird as taboo and eating its meat would cause an unborn child to cause the death of its mother. The jabiru is known as "karinji" and is the totem of a group known as the Karinji people.
The difference in iris colour among the sexes was noted in 1865 by A D Bartlett, the superintendent in charge of the collection at the Zoological Society of London. The similarity in this aspect with the African saddle-billed stork was noted by Bartlett and commented on by J. H. Gurney. Charles Darwin who corresponded with Bartlett was well aware of this and used it as one of the examples of sexual dimorphism among birds. John Gould in his handbook to the birds of Australia noted that the meat of the bird "... has a fishy flavour, too over-powerful to admit of its being eaten by any one but a hungry explorer."
- BirdLife International (2012). "Ephippiorhynchus asiaticus". IUCN Red List of Threatened Species. Version 2013.2. International Union for Conservation of Nature. Retrieved 26 November 2013.
- Birdlife International
- Elliott, A. (1992). "Family Ciconiidae (Storks)". In del Hoyo, J., Elliott, A., & Sargatal, J. Handbook of the Birds of the World 1. Lynx Edicions, Barcelona. p. 463.
- Hancock, J & JA Kushlan & MP Kahl (1992). Storks, Ibises and Spoonbills of the World. Academic Press.
- Sundar KSG & GP Clancy and Shah, N (2006). "Factors affecting formation of flocks of unusual size and composition in Black-necked Storks (Ephippiorhynchus asiaticus) in Australia and India". Emu 106 (3): 253–258. doi:10.1071/MU05014.
- Whistler, Hugh (1949). Popular handbook of Indian birds (4 ed.). Gurney and Jackson, London. pp. 502–503.
- Rasmussen PC & JC Anderton (2005). Birds of South Asia: The Ripley Guide. Volume 2. Smithsonian Institution & Lynx Edicions. pp. 63–64.
- Baker, ECS (1929). The Fauna of British India, Including Ceylon and Burma. Birds. Volume 6 (2 ed.). Taylor and Francis, London. pp. 326–327.
- Peters, J.L. (1931). Check-list of birds of the world. Harvard University Press, Cambridge, Massachusetts. pp. 1–345.
- Kahl,MP (1973). "Comparative ethology of the Ciconiidae. Part 6. The Black-necked, Saddlebill and Jabiru Storks (genera, Xenorhynchus, Ephippiorhynchus and Jabiru". Condor 75 (1): 17–27. doi:10.2307/1366532.
- Wood, DS (1984). "Concordance between classifications of the Ciconiidae based on behavioral and morphological data". Journal of Ornithology 125 (1): 25–37. doi:10.1007/BF01652936.
- Slikas, B. (1997). "Phylogeny of the avian family Ciconiidae (Storks) based on cytochrome b sequences and DNA – DNA hybridisation distances". Molecular Phylogenetics and Evolution 8 (3): 275–300. doi:10.1006/mpev.1997.0431. PMID 9417889.
- Bonaparte, CL (1855). "Comptes Rendus hebdomadaires des séances de l'Académie des Sciences, Paris" 40. p. 721.
- Gray, George Robert (1871). Hand-list of Genera and Species of Birds in the British Museum. Part 3. British Museum. p. 35.
- Sharpe, R B (1899). A hand-list of the genera and species of birds. British Museum. p. 191.
- Peters, JL (1931). Check-list of the birds of the World. Volume 1. Harvard University Press, Cambridge.
- McAllan, I. A. W. & Bruce, M. D. (1989). The birds of New South Wales. A working list. Biocon Research Group, Sydney.
- Christidis, L. & Boles, W. E. (2008). Systematics and taxonomy of Australian birds. CSIRO Publishing, Australia. pp. 105–106. ISBN 0643065113.
- Rahmani, A.R. (1989). "Status of the Black-necked Stork Ephippiorhynchus asiaticus in the Indian subcontinent". Forktail 5: 99–110.
- Maheswaran G & AR Rahmani & MC Coulter (2004). "Recent records of Black-necked Stork Ephippiorhynchus asiaticus in India". Forktail 20: 112–116.
- Abdulali, Humayun (1967). "On the occurrence of the Blacknecked Stork [Xenorhynchus asiaticus (Latham)] in the Bombay Konkan". J. Bombay Nat. Hist. Soc. 64 (2): 367.
- Roberts, T.J. (1991). Birds of Pakistan. Volume 1. Regional studies and non-passeriformes. Oxford University Press, Karachi. pp. 104–105.
- Morton, S. R.; Brennan, K. G. and Armstrong, M. D. (1993). "Distribution and abundance of Brolgas and Black-necked Storks in the Alligator Rivers region, Northern Territory". Emu 93 (2): 88–92. doi:10.1071/MU9930088.
- Sundar, K. S. G. (2004). "Effectiveness of road transects and wetland visits for surveying Black-necked Storks Ephippiorhynchus asiaticus and Sarus Cranes Grus antigone in India". Forktail 21: 27–32.
- Marchant, S. & Higgins, P. J. (ed.). Handbook of Australian, New Zealand and Antarctic Birds. Volume 1. Ratites to Ducks. Oxford University Press, Melbourne.
- Bell, H.L. (1963). "Distribution of the Jabiru in south-eastern Australia". Emu 63 (3): 201–206. doi:10.1071/MU963201.
- Sundar, K. S. G. (2003). "Notes on the breeding biology of the Black-necked Stork Ephippiorhynchus asiaticus in Etawah and Mainpuri districts, India". Forktail 19: 15–20.
- Ishtiaq F; AR Rahmani, MC Coulter and Sàlim Javed (2004). "Nest-site characteristics of Black-necked Stork (Ephippiorhynchus asiaticus) and Woolly-necked Stork (Ciconia episcopus) in Keoladeo National Park, Bharatpur, India". J. Bombay Nat. Hist. Soc. 101 (1): 90–95.
- Santiapillai, C. & Dissanayake, S. R. B. & Alagoda, T. S. B. (1997). "Observations on the Black-necked Stork (Ephippiorhynchus asiaticus) in the Ruhuna National Park, Sri Lanka". Tigerpaper 24: 7–11.
- Khan, M. A. R. (1984). "Conservation of storks and ibises in Bangladesh". Tigerpaper 11: 2–4.
- Round, P.D. & Amget, B. & Jintanugol, J. & Treesucon, U. (1988). "A summary of the larger waterbirds in Thailand". Tigerpaper 15: 1–9.
- Sundar, K. S. G. (2004). "Group size and habitat use by Black-necked Storks Ephippiorhynchus asiaticus in an agriculture-dominated landscape in Uttar Pradesh, India". Bird Conservation International 14 (4): 323–334. doi:10.1017/S0959270904000358.
- Hume, AO (1890). The nests and eggs of Indian birds 2 (2 ed.). R H Porter, London. pp. 265–268.
- McCann, C. (1930). "Nidification of storks". J. Bombay Nat. Hist. Soc. 34 (2): 579–581.
- Ali, S and Ripley, S.D. (1978). Handbook of the birds of India and Pakistan 1 (2 ed.). Oxford University Press. pp. 104–105.
- Sundar, K.S.G. & Deomurari, A. & Bhatia, Y. & Narayanan, S.P. (2007). "Records of Black-necked Stork Ephippiorhynchus asiaticus breeding pairs fledging four chicks". Forktail 23: 161–163.
- Sundar, K.S.G. (2011). "Agricultural intensification, rainfall patterns, and large waterbird breeding success in the extensively cultivated landscape of Uttar Pradesh, India". Biological Conservation 144 (12): 3055–3063. doi:10.1016/j.biocon.2011.09.012.
- Baral,HS (1995). "Black-necked Stork endangered". Newsletter for Birdwatchers 35 (4): 74–75.
- Banerjee,DP; Bavdekar,SP; Paralkar,VK (1990). "Aggressive behaviour of Blacknecked Storks towards Cranes". J. Bombay Nat. Hist. Soc. 87 (1): 140.
- Dorfman, E.J. & Lamont, A. & Dickman, C. R. (2001). "Foraging behaviour and success of Black-necked Storks (Ephippiorhynchus asiaticus) in Australia: implications for management". Emu 101 (2): 145–149. doi:10.1071/MU00008.
- Maheshwaran, G. and Rahmani, A. R. (2001). "Effects of water level changes and wading bird abundance on the foraging behaviour of Black-necked storks Ephippiorhynchus asiaticus in Dudwa National Park, India". J. Biosc. 26 (3): 373–382. doi:10.1007/BF02703747.
- Panday,Jamshed D (1974). "Storks preying on live birds". J. Bombay Nat. Hist. Soc. 71 (1): 141.
- Verma, A. (2003). "Feeding association of Marsh Harrier Circus aeruginosus and Black-necked Storks Ephippiorhynchus asiaticus in Keoladeo National Park (Bharatpur, India)". Aquila. 109–110: 47–50.
- Sundar, K. S. G. and Kaur, J. (2001). "Distribution and nesting sites of the Blacknecked Stork Ephippiorhynchus asiaticus". J. Bombay Nat. Hist. Soc. 98 (2): 276–278.
- Chauhan R & H Andrews (2006). "Black-necked Stork Ephippiorhynchus asiaticus and Sarus Crane Grus antigone depredating eggs of the three-striped roofed turtle Kachuga dhongoka". Forktail 22 (174–175).
- Whiting, S. D. and Guinea, M. L. (1999). "Nocturnal foraging by the Black-necked Stork Ephippiorhynchus asiaticus on sea turtle hatchlings". Emu 99 (2): 145–147. doi:10.1071/MU99017B.
- Clancy, G.P. (2009). Ecology, conservation and management of Black-necked Stork Ephippiorhynchus asiaticus. Unpublished PhD thesis, University of New England, Armidale, New South Wales, Australia.
- Sundar, K.S.G (2011). "Farmland foods: Black-necked Stork Ephippiorhynchus asiaticus prey items in an agricultural landscape". Forktail 27: 98–100.
- Sundar, K.S.G. (2005). "An instance of mortality and notes on behaviour of Black-necked Storks Ephippiorhynchus asiaticus". J. Bombay Nat. Hist. Soc. 102 (1): 99–101.
- Comway, M. (1991). "Notes on the behaviour and food-begging calls of a juvenile Black-necked Stork Xenorhynchus asiaticus". Australian Bird Watcher 14 (1): 29.
- Kumar P & BK Tandan (1971). "The species of Ardeicola (Phthiraptera-Ischnocera) parasitic on the Ciconiidae". Bull. Br. Mus. Nat. Hist. (Ent.) 26 (2): 119–158.
- Wahid, S (1962). "On a new trematode from a black-necked stork, Xenorhynchus asiaticus". J. Helminthol. 36: 211–214. doi:10.1017/S0022149X00022495. PMID 14004399.
- Clancy, G.P. (2010). "Causes of mortality in the Black-necked Stork Ephippiorhynchus asiaticus australis in New South Wales". Australian Field Ornithology 27: 65–75.
- Grubh BR & PB Shekar (1968). "Blacknecked Stork (Xenorhynchus asiaticus) and the marriage of Mirshikars". Newsletter for Birdwatchers 8 (3): 1–2.
- Barman,R; Talukdar,BK (1996). "Nesting of Blacknecked Stork Ephippiorhynchus asiaticus in Panidihing, Assam". Newsletter for Birdwatchers 36 (5): 95.
- "Emu and the Jabiru". Australian Museum. Retrieved 11 June 2010.
- Spencer, Baldwin and Gillen, F. J. (1904). The northern tribes of central Australia. Macmillan and co, London. pp. 197, 614.
- Gurney, J. H. (1865). "A seventh additional list of birds from Natal". The Ibis 7 (3): 263–276. doi:10.1111/j.1474-919X.1865.tb05772.x.
- Darwin, C (1871). The descent of man and selection in relation to sex 2. John Murray, London. p. 129.
- Gould, J (1865). Handbook to the birds of Australia 2. Published by the author. p. 293.
- Maheswaran, G. and Rahmani, A. R. (2002) Foraging behaviour and feeding success of the black-necked stork (Ephippiorhychus asiaticus) in Dudwa National Park, Uttar Pradesh, India. J. Zool. 258: 189–195.
- Maheswaran, G. (1998) Ecology and behaviour of Black-necked Stork (Ephippiorhynchus asiaticus Latham, 1790) in Dudwa National Park, Uttar Pradesh. Ph.D. thesis, Centre of Wildlife and Ornithology, Aligarh Muslim University, Aligarh, India.
- Farah Ishtiaq, Sálim Javed, Malcolm C. Coulter, Asad R. Rahmani 2010 Resource Partitioning in Three Sympatric Species of Storks in Keoladeo National Park, India. Waterbirds 33(1):41–49
- Maheshwaran G & AR Rahmani 2008 Foraging technique and prey-handling time in black-necked stork (Ephippiorhynchus asiaticus) Integrative Zoology 3(4):274–279 doi:10.1111/j.1749-4877.2008.00101.x
|Wikimedia Commons has media related to Ephippiorhynchus asiaticus.|
- Birds in my backyard, Australia
- New South Wales, Australia
- Images and videos
- 3D specimen
- BirdLife Species Factsheet