• Summary
• Text account
• Data table and detailed info
• Distribution map
• Reference and further resources

Justification of Red List category
This species has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <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). Despite the fact that the population trend appears to be decreasing, the decline is not believed to be sufficiently rapid to approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size is extremely large, and hence does not approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.

Population justification
The global population is estimated to number c.3,600,000-4,500,000 individuals (Wetlands International 2015). The European population is estimated at 295,000-639,000 males, which equates to 590,000-1,280,000 mature individuals (BirdLife International 2015).

Trend justification
The overall population trend is decreasing, although some populations have unknown trends (Wetlands International 2015). The European population trend is estimated to be stable (BirdLife International 2015).

This species breeds in the Arctic regions of North America and Eurasia. It is migratory, wintering pelagically off central-western South America, in the Arabian Sea, and from central Indonesia to western Melanesia (del Hoyo et al. 1996).

Behaviour This species is fully migratory and travels over land on both broad and narrow fronts (del Hoyo et al. 1996) using favoured lakes as staging points on route (Hayman et al. 1986). It breeds from late-May to August (Hayman et al. 1986) in solitary pairs, occasionally forming loose colonies where suitable habitat is restricted (del Hoyo et al. 1996). The species leaves the breeding grounds between late-June and early-September (Hayman et al. 1986), migrating in gregarious flocks and wintering at sea in flocks of 20-100 (del Hoyo et al. 1996). Habitat Breeding The species breeds in the Arctic on coastal and inland tundra, forest tundra and alpine tundra near lakes, pools (del Hoyo et al. 1996), ponds, lagoons, streams or other permanent water-bodies (Johnsgard 1981) with marshy margins overgrown with grass, sedge or moss (Johnsgard 1981, del Hoyo et al. 1996) in freshwater marshes and bogs (Hayman et al. 1986). It may also frequent coastal moorland, flood-plains and islets in large rivers, and in Iceland it commonly nests on sparsely vegetated lava deserts (del Hoyo et al. 1996). Non-breeding On passage the species frequents inland saline and hypersaline lakes (del Hoyo et al. 1996) as well as reservoirs, sewage-ponds and coastal marshes (Hayman et al. 1986). During the winter it is largely pelagic however, foraging at sea in upwelling zones and marine areas with a high abundance of plankton (del Hoyo et al. 1996). Diet Breeding In its breeding range its diet consists of insects (especially adult and larval Diptera, beetles, caddisflies, ants and Hemiptera) and other small invertebrates (e.g. snails, crustaceans and annelid worms) (del Hoyo et al. 1996), larval amphibians (tadpoles) (Johnsgard 1981) and seeds (del Hoyo et al. 1996). Non-breeding On passage the species may take larval brine-flies (Ephydra spp.) from saline lakes, but when feeding pelagically during the winter it feeds on zooplankton (e.g. euphausiids and calanoid copepods) and other floating planktonic particles (del Hoyo et al. 1996). Breeding site The nest is a shallow scrape on bare ground or amongst sparse vegetation (del Hoyo et al. 1996) in sedge thickets or damp, grassy or hummocky areas close to water (Flint et al. 1984). Management information In the UK management regimes to benefit the species include increasing the area of open water in mires by digging small pools, controlling water-levels and providing tussocky vegetation suitable for nesting (through grazing by ponies and cattle) (O'Brien et al. 1997).

The species faces ongoing changes to habitat caused by increasing temperatures and impact of climate change (Huntley et al. 2007). The population of Red-necked Phalaropes in the Bay of Fundy, Canada, dropped from 2,000,000-3,000,000 birds in the late 1970s to early 1980s to virtual absence by 1989 (Nisbet and Veit 2015). This is thought to have been caused by the effect of 1982/83 El Niño Southern Oscillation (ENSO) event on the population’s wintering area off Ecuador and Peru, likely due to a change in currents reducing the availability of their plankton prey (Nisbet and Veit 2015). A similar, albeit less extreme, decline was observed in many other Red-necked Phalarope populations both in Europe and the Americas (Nisbet and Veit 2015). This implies the species may be adversely affected by the predicted increase in ENSO events (Timmermann et al. 1999). Habitat destruction, including from peat extraction could also impact the species during its breeding stage. Coastal dredging could also reduce available habitat and prey while at sea (O'Brien et al. 1997). It is vulnerable to invasive alien predators (Biodiversity in Sweden 2012), as well as human disturbance on its breeding grounds.

Conservation Actions Underway
The following information refers to the species's European range only: This species is found on Annex I of the EU Birds Directive.

Conservation Actions Proposed
The following information refers to the species's European range only: Key areas of habitat should be protected from alteration and disturbance. Control of alien predators may be necessary in some areas.

Text account compilers
Miller, E., Stuart, A., Calvert, R., Butchart, S., Ekstrom, J., Ashpole, J, Martin, R.

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Recommended citation
BirdLife International (2024) Species factsheet: Red-necked Phalarope Phalaropus lobatus. Downloaded from https://datazone.birdlife.org/species/factsheet/red-necked-phalarope-phalaropus-lobatus 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.