|Scientific Name:||Polysticta stelleri|
|Species Authority:||(Pallas, 1769)|
|Red List Category & Criteria:||Vulnerable A2bcd+3bcd+4bcd ver 3.1|
|Contributor(s):||Artukhin, Y., Burfield, I., Dau, C., Laing, K., Pihl, S., Solovyeva, D., Stehn, H., Stehn, R. & Martin, K.|
|Facilitator/Compiler(s):||Butchart, S., Derhé, M., Ekstrom, J., Gilroy, J., Harding, M., Temple, H., Anderson, O.|
This species is listed as Vulnerable because it is undergoing a rapid population reduction, particularly in the key Alaskan populations. Further studies are needed to determine the causes of these declines, and whether some populations may have shifted to unsurveyed areas within the range.
|Range Description:||Polysticta stelleri breeds between the Kolyma Delta and the Yamal Peninsula, Russia, and on the Arctic plain of Alaska, USA (C. Dau in litt. 1999, Frederickson 2001). A remnant population breeds in western Alaska. Non-breeding populations summer in Novaya Zemlya, Russia, northern Norway and adjacent Russian waters, and south-west Alaska (C. Dau in litt. 1999). Birds breeding east of the Khatanga Gulf, Russia, winter in the Bering Sea. Small numbers winter in northern Japan. Birds breeding west of the Khatanga Gulf winter in the north-east Atlantic Ocean and the Baltic Sea. The total current population estimate is 110,000-125,000 individuals. Wintering populations in Europe were estimated at 7,700-20,800 individuals in 2000 (BirdLife International 2004), but this did not include all Russian populations: the total for Europe and Russia is estimated at 23,060-36,160 individuals. In Europe, marked declines have been noted in recent years, with numbers falling by an estimated 13% per annum in the Baltic between 1994 until 2003 and by 8% per annum in Norway between 1985 and 2003 (I. Burfield in litt. 2005; Žydelis et al. 2006). Estimates of birds wintering in Alaska declined from 137,904 in 1992 to 74,369 individuals in 2011 (Larned 2012), which was 9% below the 1992-2010 mean. The decline rate is equivalent to 2.3% per year; however, a higher frequency of optimally-timed counts in early years of the survey likely resulted in a slight negative trend bias of unknown magnitude (Larned 2012). The poorly known population wintering in east Asia may have declined by 20-40% to c.20,000-25,000 birds (R. A. Stehn in litt. to Anseriformes Draft Action Plan), including 10,000-15,000 birds recently estimated to winter in the Russian Far East (D. Solovieva in litt. 2005). The number of eiders wintering on Bering Island, in the Commander Islands near Kamchatka, Russia, declined from estimates of 10,000 in the 1960s (Marakov 1965) to between 3,356-4,994 in 2005, 2006 and 2007 (Y. Artukhin, per K. Laing in litt. 2007, Belobrov and Artukhin 2008). It is possible that some of these declines reflect population redistribution to unknown areas. It has been speculated that declines in the Baltic could result from the population shifting to waters around the Kola Peninsula, Russia (Žydelis et al. 2006), although a survey of parts of this area in 2003 did not reveal sufficiently large numbers to confirm this (Krasnov et al. 2004).|
Native:Estonia; Finland; Japan; Latvia; Lithuania; Norway; Poland; Russian Federation; Sweden; United States
Vagrant:Belgium; China; Denmark; France; Germany; Greenland; Iceland; Netherlands; Svalbard and Jan Mayen; United Kingdom
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||Various population estimates include: c.10,000-15,000 wintering individuals in north Norway and the south-east Baltic (based on a count of 4,297 off Kola Peninsula in April 2003 [Krasnov et al. 2004], 2,250 in the south Baltic in 2003 [Zydelis et al. 2006] and c.2,000-4,000 individuals wintering off Norway [unpublished information supplied by Wetlands International Specialist Groups to Wetlands International 2006]); c.100,000-110,000 wintering individuals in the north Pacific (counts in north America declined from 137,904 in 1992 to 77,329 in 2003, to 74,369 in 2011, forming basis of 2003 north American population estimate of 90,000-95,000 individuals [K. Laing in litt. 2005 to Wetlands International 2006]; however, the population has since declined to 74,369 individuals in 2011 [Larned 2012]); c.20,000 migrating individuals through the Kamchatka Peninsula in spring (Gerasimov and Gerasimov 2003) and c.100-10,000 breeding pairs and c.50-1,000 wintering individuals in Russia (Brazil 2009).|
|Habitat and Ecology:||Behaviour This species is migratory (del Hoyo et al. 1992). It begins to breed in June, nesting sometimes in single pairs in very low densities (roughly one pair per 100 acres was recorded on the Kashunuk River in the 1960s) (Johnsgard 1978), but occasionally in small colonies of up to 60+ nests (Kear 2005). Around the time of hatching, males gather in large flocks off the coast near the breeding ground (Johnsgard 1978). Shortly after hatching the female moves her brood to the coast where they form 'herds' (Johnsgard 1978). The species migrates up to 3000km to its moulting sites (Johnsgard 1978, Kear 2005), where it becomes flightless for a period, before some continue migration to more distant wintering sites (Petersen et al. 2006). The timing of the moult migration appears to be highly variable, occurring sometimes as early as August, but in some years not until November, in which case the moult occurs prior to arrival (Johnsgard 1978). On the moulting grounds it forms flocks that may exceed 50,000 birds (Kear 2005, Laubhan and Metzner 1999). Congregations of a similar size also occur also in the spring when pair formation occurs prior to departure for the breeding grounds (Kear 2005). Spring migration commences in March in east Asia (Kear 2005), and elsewhere it begins in April, usually peaking in May (Kear 2005). Arrivals on the breeding grounds begin in early June (Kear 2005). Some small flocks remain throughout the summer in the wintering quarters at Varangerfjiord (Kear 2005). Habitat Breeding This species regularly breeds several kilometres inland (Kear 2005). It inhabits pools of various shapes and sizes in areas that characterise flat coastal belt within open tundra (Kear 2005). In the Lena Delta and Barrow areas it favours moss-lichen polygonal tundra (Kear 2005). It forages in areas of fresh, saline or brackish water, and tidal flats (Johnsgard 1978). Following hatching all birds move to coastal habitats (Johnsgard 1978). Non-breeding It winters mostly at sea, along low-lying rocky coasts, frequenting bays and river mouths (del Hoyo et al. 1992). It forages in water that is less than 10m deep (Madge and Burn 1988), and particularly favours areas where freshwater streams enter the sea (Madge and Burn 1988). Diet It feeds chiefly on molluscs, crustaceans and other marine invertebrates (del Hoyo et al. 1992). During the breeding season, some freshwater prey is taken including chironomid and caddisfly larvae (Johnsgard 1978). During moult, bivalve molluscs are the primary food source (Petersen 1981). Breeding site Nests are built on small hummocks or in depressions between hummocks, usually within a few metres of a tundra pond, and are often well-concealed by grass (Johnsgard 1978). The nests are deep and lined with lichens, grass and down (Kear 2005).|
|Systems:||Terrestrial; Freshwater; Marine|
Subsistence hunting has been ongoing in Alaska since the late 19th century, and may have affected breeding populations here. Over-hunting in Siberia and in other breeding areas may be impacting the population. Studies at Barrow indicate that the species is subject to lead poisoning from the historical (and probably ongoing, but illegal since a nationwide ban in 1991 [Morse 2009]) use of lead shot. Disease and water pollution may impact eiders in their wintering area in south-west Alaska. Eiders breeding in Russia are subject to human subsistence harvest and exposure to lead shot. Males are subject to particular hunting pressure as they arrive on moulting grounds before females (Morse 2009). Declines of wintering birds on Bering Island, Russia appear to be greater on the west coast near the only village on the island; new protective zones are being proposed there (Y. Artukhin per K. Laing in litt. 2007). Nest predation by mammalian and avian predators (e.g. Arctic Fox Alopex lagopus, Snowy Owl Nyctea scandiaca and Pomarine Jaeger Stercorarius pomarinus) appears to be a threat on Alaskan breeding grounds; no nesting was observed on breeding grounds near Barrow between 2001 and 2004, but nesting has since occurred with some success following the inception of fox control in 2005 (Safine 2011). Increasing human habitation of Arctic regions has increased the range and numbers of Ravens and some large gulls, leading to a greater risk of predation (Kear 2005). Recent dramatic changes in Arctic sea ice extent and thickness north of Alaska and Russia may affect eiders in unknown ways. Habitat loss also occurs through prospecting for, and the exploitation of, natural resources such as oil and gas (Kear 2005). The increasing traffic of tankers carrying oil from Arctic areas imposes the risk of contamination following spills (Kear 2005). It is not currently clear which of these many factors is driving the overall decline (K. Laing in litt. 2004, Žydelis et al. 2006). There are concerns in Alaska that a road-building project approved by the United States Congress in 2009 may impact the species (Morse 2009).
Conservation Actions Underway
A European action plan was published in 2000, and the US Fish and Wildlife Service successfully proposed the critical habitat designation of 4,528 km2 of coastal habitat for the conservation of this species (Anon. 2001). It is a protected species in both Russia and the USA. Work has begun in Russia to conduct waterfowl population and subsistence harvest surveys (K. Laing in litt. 2004). A captive breeding and research programme (including 50 years of banding data) is underway in Alaska (Alaska SeaLife Center 2004). New protective zones are being proposed around wintering sites on Bearing Island (Y. Artukhin per K. Laing in litt. 2007), including additional protected zones of the Komandorskiy Reserve (Belobrov and Artukhin 2008). CMS Appendix I and II. Conservation Actions Proposed
Survey breeding and wintering grounds (particularly surrounding the Kola Peninsula, Russia) to determine population size and trends. Determine causes of current declines. Work to mitigate threats such as lead poisoning. Ensure subsistence harvest is sustainable. Support and extend the captive breeding programme to support future reintroductions and supplementation.
|Citation:||BirdLife International 2013. Polysticta stelleri. The IUCN Red List of Threatened Species. Version 2015.2. <www.iucnredlist.org>. Downloaded on 04 August 2015.|
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