Data Zone
Justification of Red List category
This species is listed as Near Threatened on the basis that it is expected to undergo a moderately rapid population decline over the next three generations owing to human pressures on riverine ecosystems, including the construction of dams. It has already undergone precipitous declines in South-East Asia but its status currently appears more secure in India.
Population justification
The population size has not been estimated here, but the species has been described as locally common (Hume and Kirwan 2017).
Trend justification
Precipitous declines have occurred in parts of South-East Asia, but trends in India, which now probably holds the bulk of the population, are less clear, making analysis of past population trends difficult. Nevertheless, the species is expected to undergo a moderately rapid reduction over the next three generations, as threats, such as dam construction and disturbance, increase in prevalence.
Esacus recurvirostris occurs across a wide range in southern Asia, being found in Iran, Pakistan, India, Sri Lanka, Nepal, Bhutan, Bangladesh, Myanmar, Thailand, Laos, Cambodia, Vietnam and southern China (del Hoyo et al. 1996). Formerly numerous, in Bangladesh there have been hardly any sightings in the last 20 years (P. Thompson in litt. 2013), while in Nepal it has declined in range and population and may now be restricted to the Koshi Barrage area, with the national population now possibly as low as ten individuals (C. Inskipp & H. S. Baral in litt. 2013). The recent status in Myanmar is poorly-known, but it has disappeared from Bagan since 1995 (C. Robson in litt. 2013), although the country still contains large tracts of potentially suitable habitat and in 2005-2007 it was abundant in the river network of the Hukaung Valley (J. W. Duckworth in litt. 2016). In Laos the major losses occurred decades ago but declines have continued (surveys in 1997-2004 found a large population in the Mekong between Vientiane and Louangphabang, but an intensive survey there in 2011-2012 found no birds [Duckworth and Timmins 2013]). There is a lack of recent information from the Mekong south of Vientiane, although the species persisted there in the 1990s (Thewlis et al. 1998, Duckworth et al. 1999), and national extinction in Laos seems likely (J. W. Duckworth in litt. 2016). There has been a recent sighting from Vietnam on coastal sand dunes (Robson et al. 2016, C. Robson in litt. 2016), and this habitat is probably under less pressure than riverine sandbanks in this country (C. Robson in litt. 2016). It remains more numerous on the Indian subcontinent, where it prefers larger rivers but also occurs on still water, but declines are believed to have taken place here too (P. Jayadevan in litt. 2013).
It favours riverbed shingle and rocks, stony banks and mud around large lakes, but sometimes visits nearby grassy flats and also occurs infrequently on coastal beaches and estuaries. It is thought to be largely sedentary, but undergoes local movements forced by rising water levels (del Hoyo et al.1996).
Nest predation by dogs, disturbance by fishermen and domestic animals, and opportunistic harvesting has caused chronically low breeding success of riverine nesting birds throughout South-East Asia (Goes in press). In Nepal the species is seriously threatened by disturbance and the degradation and loss of its riverine habitat. The multitude of hydroelectric dam projects completed, underway and planned on large rivers in its range, which threaten to alter flow regimes and inundate nesting habitat downstream, is now perhaps the most significant threat across much of the range. On the Sesan and Sekong rivers in Cambodia, the species has nearly disappeared (A. Claassen in litt. 2013). This recent precipitous decline on the Sesan is probably due to upstream Vietnamese dams (sudden water level rises inundating nests), and imminent extinction there seems unavoidable, and with further dams planned the fate of the small Sekong population does not seem more promising, even if appropriate conservation actions are implemented (Goes in press). Planned hydro-power dams on the main Mekong channel in southern Laos, at Stung Treng and Sambor (Kratie) would lead to major alteration of flood regimes and river ecology if built, and could arguably lead to regional extinction in the medium term (Goes in press).
Conservation and research actions in place
No targeted conservation actions are known for this species, although some of its habitat is protected.
Conservation and research actions proposed
There is urgent need for nest-protection programmes and monitoring of human activities during the dry season. Carry out regular surveys to monitor population trends throughout its range. Quantify the severity and impact of threats across its range. Carry out awareness-raising activities to alleviate human pressures on riverine ecosystems, and lobby against high-impact dam projects. Increase the area of suitable habitat that receives effective protection. Ensure that the species receives national protection, and where this is already in place, ensure that it is enforced (J. W. Duckworth in litt. 2016).
Text account compilers
Westrip, J., Ekstrom, J., Butchart, S., Symes, A.
Contributors
Duckworth, J.W., Porter, R., Claassen, A., Robson, C., Inskipp, C., Srinivasan, S., Baral, H., Timmins, R.J., Goes, F., Jayadevan, P., Krishnan, A., Thompson, P.
Recommended citation
BirdLife International (2024) Species factsheet: Great Thick-knee Esacus recurvirostris. Downloaded from
https://datazone.birdlife.org/species/factsheet/great-thick-knee-esacus-recurvirostris on 23/12/2024.
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 23/12/2024.