Data Zone
Justification of Red List category
Overall, this species has undergone a moderately rapid population reduction, which is projected to continue, and it has a moderately small population. It is therefore classed as Near Threatened.
Population justification
There are thought to be 1,000 asiaticus (G. Sundar in litt. 2002, 2006), plus possibly up to 20,000 breeding australis (S. Garnett in litt. 2006), giving perhaps up to 21,000 mature individuals and therefore up to c.31,000 individuals in total. In light of the uncertainty surrounding this figure, a conservative range estimate of 15,000-35,000 individuals is preferred.
Trend justification
It is known that the Asian population has declined and, whilst the timing of this decline is not known, much of it is likely to have occurred during the last 60 years. Trends in Australia have not been properly evaluated; however, this population appears relatively stable. The overall population is estimated to be declining at a slow to moderate rate.
Ephippiorhynchus asiaticus occurs in South Asia, South-East Asia and Oceania. In South Asia it is found in Pakistan (previously frequent in lower Sind, breeding in the Indus delta until the 1970s, now a straggler), Nepal (rare resident and winter visitor to the terai), India (a widespread resident, but now generally rare and local, and may now be absent in many areas in the south [G. Maheswaran in litt. 2003]), Bhutan (likely as a non-breeder), Bangladesh (former resident, now a vagrant), and Sri Lanka (fewer than 50 mature individuals resident, principally in the dry lowlands). In South-East Asia it occurs in Myanmar (formerly a widespread resident, current status unclear but certainly scarce), Thailand (formerly quite widespread, now a rare resident in the peninsula, almost extinct), Laos (previously a widespread non-breeding visitor, probably breeding in the south, but now extremely rare), Cambodia (previously fairly common; regular recent records, with small numbers breeding, but none breeding in Prek Toal in 2013 or 2014 [Visal and Mahood 2015]), and Indonesia (apparently once present in the Sundaic region, but now extinct there; population >650 in south Papua, formerly Irian Jaya). The species was thought to be extinct in Vietnam, with no records since 1987, but in 2003, two individuals were recorded during a survey of Yok Don National Park (Anon. 2003). In Oceania, subspecies E. a. australis it is found in Papua New Guinea (very local, but occasionally not uncommon) and Australia (relatively large and stable population in the north, c. 80 pairs in New South Wales appear to be stable (Clancy 2009, Clancy 2010b, Clancy & Ford 2013, Clancy & Kingsford 2015). In New South Wales, Australia, the range and breeding distribution has not changed greatly since 1990 (Clancy 2010a). The combined South and South-East Asia populations are thought to number fewer than 1,000 individuals (K.S.G. Sundar in litt. 2006). While it is in decline in South Asia, in South-East Asia it has dwindled to the brink of extinction. However, a population of c.29 pairs studied in Uttar Pradesh (India) had high productivity and low mortality and has been judged to be at least stable, if not a source for neighbouring populations (Sundar 2003, 2011a). The districts of south-western Uttar Pradesh are the species stronghold in India (K.S.G. Sundar in litt. 2007). Between 1996 and 2003, the species was judged to be in decline at 32 (54%) of the 59 sites in India where it was recorded (Maheswaran et al. 2004). In Dudwa N.P. the population remains the same even after 20 years when Maheswaran visited the wetlands situated inside Dudwa as recently as May, 2016. Kaziranga N.P. in Assam, India also has a stable population but the species has almost gone extinct inside famous Keoladeo National Park, Bharatpur in Rajasthan, with only one individual sighted by Maheswaran in early 2015 (G. Maheswaran in litt. 2016). It is probably stable in south Papua and Australia, although confirmation of the trend in south Papua is required. A recent estimate places the Australian population at up to 20,000 breeding individuals and secure, although it has been contested that this is unduly optimistic and that the figure may not exceed 10,000. These estimates have been used to extrapolate a global total of c.31,000 individuals (Maheswaran et al. 2004). However, owing to the uncertainty surrounding this estimate, a range of 10,000-21,000 mature individuals is preferred as a conservative estimate of the total breeding population.
It inhabits freshwater marshes and lakes (del Hoyo et al. 1992, Sharma 2007, Clancy & Andren 2010, Clancy 2011), pools in open forest and large rivers (Sharma 2007) and flooded grassland (del Hoyo et al. 1992), up to an altitude of 1,200 m (Sharma 2007). It occasionally uses mangroves and coastal habitats (Santiapillai et al. 1997, Maheswaran et al. 2004, Sharma 2007), such as estuaries and brackish lagoons (Santiapillai et al. 1997, Clancy pers. obs). It also frequents artificial habitats such as reservoirs (Maheswaran et al. 2004), sewage ponds and irrigation stores (del Hoyo et al. 1992, Sundar 2004). Although it shows a preference for natural wetlands throughout the year, it uses similar artificial habitats like rice paddies for a short period of time, particularly during and after the monsoon season, when natural wetlands may become too deep for foraging (Sundar 2004). It will also forage in wet or dry wheat fields and flooded fallow fields, the latter especially in summer when the extent of natural wetlands is reduced (Sundar 2004). In Uttar Pradesh, north-central India the species is common in agricultural landscapes, foraging in flooded rice paddies, irrigation canals and roadside ditches (Sundar 2011b). It is carnivorous (del Hoyo et al. 1992) and has high food requirements (Rahmani 1987, Maheswaran and Rahmani 2002, Maheswaran 2003b), tending to be largely territorial, being recorded in flocks very occasionally (Sundar et al. 2006), and becoming more aggressive as food is depleted (Maheswaran and Rahmani 2001). It feeds in shallow water up to 0.5m deep (Garnett and Crowley 2000) but mostly 0.05 to 0.3 m in New South Wales (Clancy 2011), and takes fish (Garnett and Crowley 2000, Maheswaran and Rahmani 2001, Maheswaran and Rahmani 2002, Clancy 2011), reptiles and frogs (Garnett and Crowley 2000, Clancy 2011), some waterfowl (Verma 2003, Clancy 2011), turtle eggs (Chauhan and Andrews 2006), crabs, molluscs, insects and other arthropods (Ishtiaq et al. 2010, Sundar 2011b, Clancy 2011). It has also been observed feeding on its own dead chicks in Dudwa, N.P. India (Maheswaran & Rahmani 2005). It has been observed using tactile feeding methods (Maheswaran and Rahmani 2001, Maheswaran and Rahmani 2002), although more recent research in New South Wales found visual methods to be most commonly used (Clancy 2011). Foraging occurred most commonly in the morning and late afternoon, with loafing during the middle of the day (Clancy 2011). Prey-handling time increased as prey size increased and fishes of 4-6cm were more frequently taken by adult storks (Maheswaran and Rahmani 2008). It is a territorial breeder (Rahmani 1987, Santiapillai et al. 1997, Sundar 2004, Maheswaran and Rahmani 2005, Clancy & Ford 2013), and pairs stay together during successive seasons, some even after breeding is over (Sundar 2003, Maheswaran 2003b, Clancy pers. obs). Nests are built in old trees (Rahmani 1987) and occasionally on shrubs in wetlands (Clancy & Ford 2011). In India, it starts to nest from August onwards (Bhatt 2006), with earlier breeders in northern India timing their egg laying in September and October to coincide with the end of the monsoon season (Maheswaran 2003a, Sundar 2003). Consequently, breeding success is influenced positively by both the north-east and south-west monsoons (Sundar 2011a). In New South Wales, Australia, eggs are laid from May to August, with fledging occurring between October and January (Sundar et al. 2006, Clancy & Ford 2013). Breeding pairs generally raise one or two chicks and three is not uncommon (Maheswaran and Rahmani 2005), although four and five is rare (Sundar 2003, 2011a, Sundar et al. 2007). Chicks generally stay in natal territories until the subsequent breeding season, although they stay longer if adult birds do not breed in the subsequent year (Sundar 2003), although early dispersal of young was found in New South Wales, Australia, with some birds dispersing within a few months of fledging but others persisting in the territory until at least the next breeding season (Clancy & Ford 2013). Although the process of laying and raising chicks to independence takes up to 12 months, ten out of 25 pairs that bred successfully in one year, were also successful in the subsequent year (Clancy and Ford 2013).
It is threatened by a variety of factors across its range, including drainage of wetlands, felling of nest trees, development, encroachment of agriculture or aquaculture, overfishing, overgrazing, hunting and excessive capture for zoos. Consecutive years of drought can cause declines in the population (del Hoyo et al. Family CICONIIDAE 1992), though one population in western Uttar Pradesh is resilient to dry years as long as these are interspersed with years of normal and above-normal rainfall (Sundar 2011a). In India, the freshwater wetlands that this species relies upon are under great pressure from expanding human populations (Maheswaran et al. 2004). The most frequent threat to the species in this country is fishing (Santiapillai et al. 1997, Maheswaran et al. 2004), which is so intensive in places that even 5-10 cm fishes are taken (Rahmani 1987), followed by the affects of sedimentation on wetland quality (Maheswaran et al. 2004). Illegal conversions of erstwhile community-use wetlands to private fish ponds has severe and large-scale impacts on populations (Sundar et al. 2015). However, deterioration of foraging habitat through the conversion of wetlands into agricultural fields is also a major threat in India (Rahmani 1987, Maheswaran 2003a, Sundar 2004, Sundar 2011a). In the face of wetland conversions, flooded rice paddies have become important and may be promoting the dispersal of young birds and preventing the fragmentation of sub-populations (Sundar 2004). Eggs are taken in at least some parts of India (Maheswaran et al. 2004). Disturbance during the nesting season is a major threat (Rahmani 1987), but at least one population in Uttar Pradesh has very high breeding success despite being in a human-dominated agricultural landscape (Sundar 2011a). Traditional mechanisms of conservation of trees (nesting habitat) and wetlands (foraging habitat) combined with legal provisions, and cultivation using low levels of mechanisation in rural India can provide suitable conditions for this species (Sundar 2011a). Deaths due to collision with electricity wires are occasional in India (Sundar 2005), but are the main cause (c.50%) of deaths of birds of all ages in Australia. Death from apparent natural causes and unknown causes were the next equal highest category. There were only 4 deaths known from collision with wire fences in Australia (Clancy in litt. 2016). Additional threats in Sri Lanka include possible inbreeding in small populations, pesticide poisoning of wetlands and loss of mangroves to increasing salinity levels (Santiapillai et al. 1997). In Australia, the species is thought to be threatened by disturbance and habitat loss, but has not been greatly affected by the intensification of land-use in eastern Australia (Garnett and Crowley 2000, Clancy & Kingsford 2015). Sea-level rise is projected to have a negative impact upon coastal habitats. The frequent formation of mostly female-biased trios in Australia may indicate that the sex ratio of the species is skewed (Sundar et al. 2006). Large remnant trees are being replaced by plantations, particularly in the New South Wales region, and could lead to declines in prime nesting habitat (Clancy and Ford 2011). Agro-industry farming is an ongoing threat with very rapid declines suspected for the minority of populations. This has however now been seen to be untrue for at least one population that has over 30 breeding pairs (G. Sundar in litt. 2016). Drought due to climate change may be a threat, but modelling shows that as long as there are years of normal and above-normal rainfall interspersed with drought years, populations will do well (Sundar 2011a). Improper management of some man-made protected areas in India (for example, Keoladeo National Parin in Rajasthan) has failed to provide adequate environment for this species (G. Maheswaran in litt. 2016).
Conservation Actions Underway
CITES Appendix I. In Australia the species is listed as rare in Queensland and Endangered in New South Wales. It has been upgraded to Schedule I of the Indian Wildlife (Protection) Act, giving it full protection. It is a conservation priority in Cambodia. It occurs in a number of protected areas including several national parks in Australia and India. Studies on the distribution and abundance levels of this species are presently ongoing in South-East Asia and India (K.S.G. Sundar in litt. 2007). An analysis subsequent to these studies is expected to provide improved population estimates. Detailed studies have been carried out in New South Wales, Australia are providing improved population information for that state (Clancy 2010a, Clancy & Andren 2010, Clancy & Ford 2013, Clancy & Kingsford 2015). A long-term monitoring study has been established in India to understand impacts of land use change and rainfall patterns on the species (Sundar 2011a).Conservation Actions Proposed
Protect remaining habitat, especially in South and South-East Asia. Try to mitigate in advance against the loss of habitat to sea-level rise in Australia. Carry out range-wide surveys to accurately determine the total population size and trends. Prevent birds being captured for trade to collections and zoos in Asia. Prevent hunting of the species. Study the importance of flooded rice paddies for dispersal and linkage of sub-populations through genetic and telemetry studies (Sundar 2004, K.S.G. Sundar in litt. 2007). In most areas of the species's range regulate landscape-scale farming practices and development projects to incorporate maintenance and preservation of natural wetlands, and reduce changes in land-use such as conversion to drier crops (Sundar 2004). Carry out long-term research in multiple locations into its breeding biology and behaviour (Maheswaran 2003b, Sundar 2011a). Continue to monitor wetlands in northern Cambodia (using photo-traps) to help understand breeding biology and success (K.S.G. Sundar in litt. 2007). More species-specific (BNS) surveys to be undertaken across its range countries (G. Maheswaran in litt. 2016). Continue to colour band nestlings and research the impact of powerline collisions in Australia (Clancy in litt. 2016).
129-150 cm. A very large and characteristic stork. Adults have bright red legs, white body, extensive black in the wings and tail and notably a glossy iridescent black head and neck with big black bill. Genus Ephippiorhynchus unique among storks in showing sexual dimorphism in colouration: iris dark brown in male and yellow in female. Immature mostly dull brown. Similar spp. Unmistakeable. No similar spp. within the range.
Text account compilers
Benstead, P., Bird, J., Butchart, S., Garnett, S., Pilgrim, J., Taylor, J., Allinson, T, North, A.
Contributors
Garnett, S., Christidis, L., Maheswaran, G., Clancy, G., Sundar, G.
Recommended citation
BirdLife International (2024) Species factsheet: Black-necked Stork Ephippiorhynchus asiaticus. Downloaded from
https://datazone.birdlife.org/species/factsheet/black-necked-stork-ephippiorhynchus-asiaticus on 22/12/2024.
Recommended citation for factsheets for more than one species: BirdLife International (2024) IUCN Red List for birds. Downloaded from
https://datazone.birdlife.org/species/search on 22/12/2024.