Data Zone
Justification of Red List Category
This species has a small global population which is threatened by predation plus degradation of its breeding and wintering habitat. It is classified as Near Threatened as there is presently no evidence that a decline is taking place.
Population justification
The population is estimated to number fewer than 10,000 individuals, and so is placed in the band 2,500-9,999 individuals (R. Schlatter in litt. 2002). This equates to 1,667-6,666 mature individuals, rounded here to 1,500-7,000 mature individuals.
Trend justification
The population is suspected to be stable in the absence of evidence for any declines or substantial threats.
Pluvianellus socialis is local and partially resident in the extreme south of Chile and south Argentina, with part of the population wintering north to the Valdés peninsula, south-central Argentina, and sometimes as far as Buenos Aires province (Narosky et al. 1993, Chiurla 1996, Piersma 1996a). The population is estimated to number fewer than 10,000 birds (R. Schlatter in litt. 2002 to Wetlands International), and other estimates suggest it may be considerably smaller. Significant recent concentrations of non-breeding birds have included 145 and 123 on the Gallego and Chico estuaries respectively (Argentina) in 1999 (Ferrari et al. 2003).
It breeds on the open shores of freshwater or brackish lakes and shallow pools, and perhaps sometimes by rivers, in steppe-like regions up to 1,200 m, but generally at lower elevations in the south. Outside the breeding season, it occurs along rivers (Imberti 2003) and on the coast, mostly in sheltered bays, lagoons and river mouths. It feeds primarily on tiny arthropods during the breeding season, with chironomid larvae apparently forming the staple food in winter, when it forages in small flocks (Piersma 1996a).
There are few apparent reasons for its scarcity. However, the destruction and degradation of natural grassland in Patagonia by grazing livestock and introduced herbivores must have had some impact on mainland breeding habitat, and numbers are perhaps limited by the carrying capacity of the hostile environment (Fjeldså 1988, Dinerstein et al. 1995, S. Imberti in litt. 1999). Trampling of nests and chicks by grazing animals is a potential threat which has been observed in Magellanic Oystercatcher (Ferrari et al. 2003). It may be particularly vulnerable to human disturbance and further potential threats in the non-breeding season include predation by feral cats and dogs and the degradation of estuarine habitat due to oil spills, garbage dumping and sewage (Ferrari et al. 2003).
Conservation Actions Underway
CMS Appendix II. In Argentina, it breeds in Tierra del Fuego and Perito Moreno National Parks, and Bosques Petrificados Natural Monument, and it is also found in Magallanes and Laguna de los Cisnes National Reserves, Chile.
18-20 cm. Plump and subtly coloured dove-like wader. Pale grey above, dusky lores. Broad silvery grey breast band, getting darker towards distal end. Paler throat; rest of underparts white. White tail with dusky central rectrices and narrow whitish bar on dark grey wing, visible in flight. Dark bill. Bright red eye and pinker legs. Juvenile with buffy mottling on the grey parts. Similar spp. No other wader with that shape shares its unstreaked plumage pattern. Voice Rather vocal, delivers soft dove-like whistles and other calls. Hints Tame but hard to find. Always on the move in pebble lake-shores. The voice aids in locating it.
Text account compilers
Benstead, P., Butchart, S., Capper, D., Mazar Barnett, J., Sharpe, C J, Symes, A.
Contributors
Imberti, I., Schlatter, R.
Recommended citation
BirdLife International (2023) Species factsheet: Pluvianellus socialis. Downloaded from
http://www.birdlife.org on 01/04/2023.
Recommended citation for factsheets for more than one species: BirdLife International (2023) IUCN Red List for birds. Downloaded from
http://www.birdlife.org on 01/04/2023.
