Archived 2011-2012 topics: River Lapwing (Vanellus duvaucelii): request for information

Initial deadline for comments: 31 January 2012 [note that this has been moved back by about two months].

BirdLife species factsheet for River Lapwing

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.

References:

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.

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5 Responses to Archived 2011-2012 topics: River Lapwing (Vanellus duvaucelii): request for information

  1. Joe Taylor says:

    The following wording, regarding the species’s status in Cambodia, has been extracted from a document sent by Frédéric Goes on 14 October 2011:

    At Risk in Laos / Endangered in Thailand / Threatened in Cambodia. The population subsisting in the large rivers of the northeast and the upper Cambodian Mekong is unparalleled regionally, as few river stretches in Indochina and none in Thailand retain more than a few tens of birds (Timmins 2008) . . . In addition to the beam of human-related threats common to the riverine-nesting bird community . . . the recently-built hydroelectric dams on the Vietnamese part of the Sesan seem to inevitably seal the fate of this formerly healthy population. The Sesan and in a lesser measure the Sekong populations have little chance of escaping extinction in the coming 10 years. High rate of breeding failure is the main cause behind this decline (Claassen 2004). The upper Cambodian Mekong populations have so far been under less pressure from human activities and dam impacts. However, failure to effectively protect the habitat from degradation, encroachment and disturbance, and multiple hydro-electric dam projects would also result in a precipitous decline of these populations within 10-20 years. In absence of rapid conservation action, the Mekong population will soon face an accelerating rate of decline too. The species has still a healthy population, but under pressure from multiple threats and is particularly vulnerable, qualifying the species as Threatened in Cambodia. A review of its status is recommended in 5 years. The official decision to build any of the three dams in the lower Mekong (in southern Laos or northern Cambodia) would immediately qualify the species as Critical in Cambodia.

  2. Joe Taylor says:

    The following comments were sent by Richard Thewlis on 15 November 2011:

    I don’t have anything significant to add. The impact of hydroelectric projects in Laos on Lao and Cambodian populations is worrying, and probably inevitable, sadly. Again Frederic Goes comments are v helpful.

  3. Joe Taylor says:

    The following comments were sent by Will Duckworth on 24 November 2011:

    Still numerous in Lao but probably doomed on all the tributaries. The prospects of the Mekong mainstream population will be clearer after a survey there in the next few months’ time. This will cover much of the same area as covered by Duckworth et al. (2002). there have been no records on the new, massive, Nakai (Nam Theun 2) reservoir despite reasonable search effort, and any hopes that this is because it is still only a couple of years old may be dashed by the lack of records from the venerable Nam Ngum 12 reservoir (40 years old). I find it difficult to believe that there could be anywhere with really healthy populations, given that dogs, boatmen, children and so on are ubiquitous throughout its range.

  4. Simon Mahood says:

    I recorded 9 of these birds on the Sangu river in south-east Bangladesh in December 2011. It was not possible to survey the whole river so there might have been a few more, but the population there is not significant, and subject to ongoing hunting. Furthermore there is no evidence that the species successfully breeds in the area, sandbars are small and very busy with people, dogs, crows etc. As far as I know these are the only birds in Bangladesh.

  5. Praveen J says:

    Though it is believed that this species occurs in low densities, “This species generally occurs at low densities throughout most of its range (Li et al. 2009)”, it seems to congregate in high numbers in appropriate localities. During an ornithological expedition to Rajasthan, Dipu Karuthedathu, Vinay Das, Sachin Shurpali and self recorded 30+ River Lapwings at Dholpur in Rajasthan-Madhya Pradesh border (India) on the banks of River Chambal – famed for Indian Skimmers and Gharial Crocs. All the sightings were within a small area of less than a hectare – and the lapwings flocked on the sandy beds of the river where an alternate bridge was being constructed, despite high human disturbances. Hence, the species seems to be tolerant to human disturbance in degraded habitats.

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