Initial deadline for comments: 31 January 2012 [note that this has been moved back by about two months].
River Lapwing Vanellus duvaucelii inhabits larger rivers and lakes throughout much of South-East Asia, southern China and the northern Indian Subcontinent (Chandler 2009), preferring wide, slow-moving rivers with sand or gravel bars and islands (Duckworth et al. 1998). It is listed as being of Least Concern because it does not appear to approach the thresholds for Vulnerable under any of the IUCN criteria.
This species has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence of less than 20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). The population trend is not known, but the population is not believed to be decreasing sufficiently rapidly to approach the thresholds under the population trend criterion (at least a 30% decline over ten years or three generations). The population size may be small, but it is not believed to approach the thresholds for Vulnerable under the population size criterion (fewer than 10,000 mature individuals with a continuing decline estimated to be at least 10% over ten years or three generations, or with a specified population structure).
This species generally occurs at low densities throughout most of its range (Li et al. 2009), and there are several threats that are thought to be driving declines. In southern Thailand, the species is threatened by the casual off-take of eggs and chicks, and potentially by future agricultural intensification in some areas (Wells 1999). It is also threatened by incidental disturbance caused by people, livestock and dogs, and is potentially seriously impacted by the multitude of hydroelectric dam projects completed, underway and planned on large rivers in its range, which threaten to alter flow regimes (e.g. Duckworth et al. 1998, Thewlis et al. 1998). The threats of disturbance and hunting are intensified by the tendency for both V. duvaucelii and human settlers to select the same rivers, although the numbers of the species and frequency of villages are inversely correlated, which appears to confirm that there are some negative impacts from human activities (Duckworth et al. 1998).
Thewlis et al. (1998) proposed that V. duvaucelii be considered for uplisting to Near Threatened if the situation in Laos was representative of the majority of its range, as it had undergone recent declines there (Duckworth et al. 1998, Thewlis et al. 1998). Further information on the species is requested from all parts of its range, particularly on its population trends and the severity of threats. If evidence suggests that a decline approaching 30% (typically 20-29%) has occurred over the past three generations, estimated by BirdLife to be c.27 years, the species may be eligible for uplisting to Near Threatened. If evidence points towards a decline of 30% or more over the same time period, it may be considered for uplisting to Vulnerable.
Chandler, R. (2009) Shorebirds of the Northern Hemisphere. London, UK: Christopher Helm.
Duckworth, J. W., Timmins, R. J. and Evans, T. D. (1998) The conservation status of the River Lapwing Vanellus duvaucelii in southern Laos. Biol. Conserv. 84: 215-222.
Li, Z. W. D., Bloem, A., Delany, S., Martakis, G. and Quintero, J. O. (2009) Status of Waterbirds in Asia – Results of the Asian Waterbird Census: 1987-2007. Kuala Lumpur, Malaysia: Wetlands International.
Thewlis, R. M., Timmins, R. J., Evans, T. D. and Duckworth, J. W. (1998) The conservation status of birds in Laos: a review of key species. Bird Conserv. Int. 8 (Suppl.): 1-159.
Wells, D. R. (1999) The Birds of the Thai-Malay Peninsula. Volume One, Non-passerines. London, UK: Academic Press.