Data Zone
Justification of Red List category
This species has a restricted linear range and a small population. It is highly tolerant of human presence, and its habitat is not particularly vulnerable to human-induced changes. However, the many dams currently proposed for the Mekong, particularly those on sections where the river has a low gradient, have the potential to disrupt long stretches of its riverine range by flooding the river channel. Its small to moderately small population is therefore projected to undergo a moderately rapid decline over the next three generations and it is thus classified as Near Threatened.
Population justification
A preliminary population estimate of 10,000-19,999 individuals assumes that the species's population is moderately small owing to its highly specialised habitat requirements and restricted distribution. This estimate equates to 6,667-13,333 mature individuals, rounded here to 6,000-15,000 mature individuals.
Trend justification
Moderately rapid declines of 20-29% are suspected to take place in the next three generations (14.1; Bird et al. 2020) owing to the proposed construction of a number of dams (Tyler and de Juana 2020), which will almost certainly impact upon the species's specialised habitat.
Motacilla samveasnae is known, in the breeding season, from a substantial length of the River Mekong and several of its tributaries in Cambodia, extending upstream from Kampi into southern Laos, and there is a record from the non-breeding season in Thailand (occurring patchily further north up the mainstream Mekong, from the confluence of River Mun to at least Chanuman District of the Amnat Charoen province; P. D. Round in litt. 2017). The species was first recorded in Viet Nam in 2002, where it is likely to be a resident breeder (Le Tron Trai and Craik 2008). Albeit, it is no longer sighted at Yok Don National Park, Viet Nam due to changes in water level from dam construction (R. Craik in litt. 2016). In optimal habitats however, linear densities may reach many pairs per kilometre, and its numbers are certainly healthy in Cambodia.
It breeds in riverine "channel mosaic" habitat, typically in broad, lowland rivers, where the streambed is exposed to provide rocky outcrops and bushland, gravel shoals and/or sandbars, tufted grasses and annual dicotyledons. It avoids wooded areas. It will regularly feed within bushes in the water, walking along branches and picking food items from these and from leaves.
It is highly tolerant of human presence, and its habitat is not particularly vulnerable to human-induced changes. However, the many dams currently proposed for the Mekong, particularly those on sections where the river has a low gradient, have the potential to disrupt long stretches of its riverine range by flooding the river channel.
Conservation Actions Underway
Short sections of its habitat occur in several protected areas, but this is unlikely to afford much protection from dam development. Active conservation for this and other riverine wetland species will centre on holistic review and modification of proposals for large dams, and will necessitate international cooperation.
Text account compilers
Fernando, E.
Contributors
Benstead, P., Bird, J., Craik, R., Round, P. & Taylor, J.
Recommended citation
BirdLife International (2024) Species factsheet: Mekong Wagtail Motacilla samveasnae. Downloaded from
https://datazone.birdlife.org/species/factsheet/mekong-wagtail-motacilla-samveasnae 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.