Black-necked stork

Australia First described by John Latham as Mycteria asiatica, this species was later placed in the now-defunct genus Xenorhynchus based on morphology. Based on behavioural similarities, M. Philip Kahl 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. 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. ==Description==

in the Northern Territory of Australia The black-necked stork is a large bird, tall having a wingspan. The only published weight for this species was a single specimen at , but this is nearly 35% less than the mean body mass of the closely related and similar sized saddle-billed stork. Therefore, this specimen of black-necked stork could have been at the low end of sizes attainable or perhaps somewhat malnourished. 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 in all aspects except the iris; 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). ==Distribution and habitat==

, in Queensland In India, the species is widespread in the west, central highlands, and northern Gangetic plains extending east into the Assam valley, but rare in peninsular India and Sri Lanka. It extends into Southeast Asia, through New Guinea and into the northern half of Australia. 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. A combination of aerial surveys and ground counts in the middle Fly River floodplain, Papua New Guinea estimated 317 storks as of December 1994 and 249 as of April 1995. The largest known breeding population occurs in the largely agricultural 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 lived in the of Keoladeo National Park. One breeding pair has been observed in Bhagalpur district, western Bihar. 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 no longer breeding 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. Small numbers are also seen in Indian coastal wetland habitats, including in mangrove creeks and marshes. 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. bird nests are usually on trees located in secluded parts of large marshes or in cultivated fields as in India and lowland Nepal. ==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 they 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. Another call is a low high-pitched peeeeeu-peeeeu-peeeeu-peeu whistle of 10-12 notes with a ventriloquistic quality. 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. The number of stork pairs that succeed in raising chicks, and the average size of fledged broods, are strongly related to monsoonal and post-monsoon rainfall, improving in years with more rainfall. 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, darters, little grebes, northern shoveler, pheasant-tailed jacana, In Australia, they sometimes forage 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 Although predominantly diurnal, they may forage at night, and have been known to forage on moonlit nights on sea turtle hatchlings on Australian beaches. They sometimes soar in the heat of the day or rest on their hocks. When disturbed, they may stretch out their necks. Like other storks, they are quite mute 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. Black-necked storks are largely non-social and are usually seen as single birds, pairs and family groups. and a species of endoparasitic trematode, Dissurus xenorhynchi. ==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. They may be extinct in the Sundaic region. The combined South and South-east 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 permanently remove the number of breeding pairs. However, healthy breeding populations are found in unprotected and intensively cultivated agricultural landscapes, especially in south Asia and cattle raising areas in north-east Australia. Suggestions abound in literature regarding black-necked storks requiring undisturbed wetlands, but these appear valid only in areas where hunting of wildlife is common (like in some countries in south-east Asia). Few breeding populations with high breeding success are known primarily due to lack of field work. It is evaluated as least concern on the IUCN Red List. ==In culture==

(c. 1780) made for Lady Impey, probably based on a bird in the menagerie at Calcutta 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 believe eating its meat would result in an unborn child causing 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 Abraham Dee 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." == References ==

• 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. PhD 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 • == External links ==