VU
Velvet Scoter Melanitta fusca



Justification

Justification of Red List Category
This species is classified as Vulnerable due to an estimated decline over the past three generations of 30-46%. Recent data indicates that the rate of decline has slowed, although breeding data indicates continuing reductions in Scandinavia, and the trend in the Russian breeding population is unknown. Further information on the rate of decline here, as well as potential shifts in distribution and the drivers of the rapid past decline are needed to inform conservation actions.

Population justification
Population data supplied the to the European Commission (EC) in late 2019 by Member States under Article 12 of the EU Birds Directive totalled 202,000-384,000 individuals. Based on previous estimates (e.g. BirdLife International 2015; Wetlands International 2020), >95% of the global population winters in the Baltic and adjacent NW Europe, so it is reasonable to assume that this is still the case. The population that winters in the Black and Caspian Seas appears to be rapidly disappearing (Paposhvili 2018), most recently estimated at 240-420 individuals (Wetlands International 2020). The total population of Velvet Scoter is now estimated at 210,000-400,000 individuals (BirdLife International in prep.). This is assumed to roughly equate to 141,000-268,000 mature individuals.

Trend justification
An apparent rapid decline of c. 60% was estimated from wintering numbers in the Baltic Sea, which fell from c. 933,000 in 1992-1993 (Skov et al. 2011) to c. 373,000 individuals in 2007-2009. Extrapolation of the data implied that this was equivalent to a decline of c.70% over the past three generations, estimated at 18.6 years (based on a generation length of c. 6.2 years, using methods in Bird et al. [2020]). The Baltic Sea is the most important wintering area in the world for this species, holding c.93% of the global population in 1992-1993. It seemed unlikely that the proportion of the total north-west European wintering population present in the Baltic has dropped from 93% to 37% (see Skov et al. 2011), thus a very rapid decline had probably taken place. Subsequently the wintering numbers appear to have stabilised (BirdLife International in prep., M. Ellermaa in litt. 2020, N. Markones in litt. 2020, S. Nagy in litt. 2020), with recent totals estimated at 202,000-384,000 (BirdLife International in prep.) and 320,000-550,000 (Dagys & Hearn 2018). 

Evidence for rapid declines in the 1990s followed by an apparent stabilisation was also supplied by migration counts in the Baltic, including a long term decline in numbers passing Hanko Bird Observatory, Estonia, in autumn (at a rate of c. 50% over 30 years), which stopped in 1995 (M. Ellermaa in litt. 2012) and numbers have been largely stable since (M. Ellermaa in litt. 2020). Similarly, numbers passing Vyborg (eastern Gulf of Finland) decreased from an average of 130 birds/hour in 1988-1994, to 55 birds/hour in 1995-1999, and 53 birds/hour in 2000-2008, although error margins may be considerable (J. Kontiokorpi in litt. 2012, A. Lehikoinen et alin litt. 2012). Numbers recorded at Söderskär Bird Observatory have also been decreasing since the 1980s (A. Lehikoinen et alin litt. 2012).

The breeding population in the EU is estimated to have declined by approximately 30% over the past three generations (BirdLife International in prep.), and the population in the Caucasus appears close to extinction (Paposhvili 2018). The European Russian breeding population is thought to have declined by 50-80% since 1980 (Krivenko & Vinogradov 2008), which is consistent with the c. 60% decline recorded by Skov et al. (2011), although the recent Russian breeding trend is unknown (Voltzit & Kalyakin 2019).

It is therefore estimated that a very rapid decline occurred between 1992 and 2009, the majority of which likely occurred prior to 2002. Even with rough stability in the wintering population since 2009, a three generation past decline is estimated at 32-46%, but is suspected the rate will fall below 30% in following years. Future decline rates are uncertain but suspected to be moderate to moderately rapid.

Distribution and population

This species breeds in Scandinavia, from Norway and Sweden, into Finland and Estonia, and western Siberian Russia to the River Yenisey, and winters mostly in the Baltic Sea and along the coasts of Western Europe, including Estonia, Poland, Norway, Sweden, Denmark, Germany, United KingdomFrance and Spain (Kear 2005), accounting for the vast majority of the global population (Delany & Scott 2006).Very few make it as far as Ireland (mean of two individuals, BirdLife International in prep.). A variable number are seen inland in winter in central Europe, from Alpine lakes to the Danube; e.g. c. 50 annually in Switzerland (vogelwarte.ch 2020), 101-259 in Italy (although most of these are in the Gulf of Trieste, Adriatic Sea), 3-40 in Bulgaria, 20-43 in Czechia and up to 30 in Slovenia (BirdLife International in prep.). 

An estimated 240-420 birds winter in the Black and Caspian Seas (Wetlands International 2015), a considerable reduction from 1,500 individuals estimated in Delany & Scott (2006) (Paposhvili 2018). A recent survey by WWF-Turkey and Kuzey Doga Association found no evidence that the species continues to breed in Turkey (S. Isfendiyaroglu in litt. 2020), although it may still persist in unsurveyed sites. Aside from Turkey, this population did breed in Armenia, Georgia and Turkmenistan (Kear 2005), but the 25-35 pairs on Lake Tabatskuri, Georgia, may be the final breeding population (Paposhvili 2018): breeding success was low and most pairs did not even attempt to breed. This population appears to be at significant risk of extinction in the near future.

Since surveys in 1992-1993, when the estimate of the north-west European wintering population was updated to c.1 million birds, an apparent rapid decline of c. 60% was detected in the Baltic Sea, with counts in 2007-2009 putting the wintering population at c. 373,000 individuals, down from c.933,000 in 1992-1993 (Skov et al. 2011). Subsequently, numbers in the main wintering areas appear largely stable (BirdLife International in prep., M. Ellermaa in litt. 2020, N. Markones in litt. 2020, S. Nagy in litt. 2020), with recent totals estimated at 202,000-384,000 (BirdLife International in prep.) and 320,000-550,000 (Dagys & Hearn 2018).

The previous reduction is believed to have been a real decline in the species's population, rather than a shift in its geographic distribution, as other data sets corroborate this negative trend. The EU breeding population, while a small portion of the global total (c. 80% breed in Russia), is estimated to be declining at a rate of approximately 30% over the past three generations (BirdLife International in prep), and the population that winters in the Black Sea and Caspian region appears to be suffering a rapid decline on breeding grounds (S. Isfendiyaroglu in litt. 2020, Paposhvili 2018). The trend in Russia is unfortunately unknown, but numbers in Kandalaksha State Nature Reserve, north-western Russia, have declined four-fold since c. 2002 (V. V. Bianki and I. A. Kharitonova in litt. 2012). Obtaining trend estimates for this population is a high priority.

Ecology

The species breeds on wooded coastlines, small freshwater lakes, pools and rivers in northern coniferous forests, wooded Arctic tundra and alpine zones, especially where there are boulder-covered or small rocky islands available for nesting with extensive herbaceous vegetation, shrubs and low trees (Johnsgard 1978, del Hoyo et al. 1992, Snow and Perrins 1998, Kear 2005). The majority of birds winter at sea on shallow inshore coastal waters, especially in estuaries or inlets where there are large mussel-beds (Madge and Burn 1988, del Hoyo et al. 1992, Snow and Perrins 1998). The species may also occur on freshwater lakes and estuaries during migration (Madge and Burn 1988, Kear 2005). Its diet consists predominantly of molluscs, as well as crustaceans, worms, echinoderms, amphipods, isopods, small fish, and (in freshwater habitats) adult and larval insects (del Hoyo et al. 1992, Kear 2005). The species may also consume plant material on its breeding grounds (e.g. leaves and shoots) (Flint et al. 1984, del Hoyo et al. 1992). It mainly forages by diving and may feed at depths of 30-40 m during the winter (del Hoyo et al. 1992). This species is highly migratory and breeds from mid-May onwards in solitary pairs or loose groups, occasionally nesting in association with gull or tern colonies (Madge and Burn 1988, del Hoyo et al. 1992, Kear 2005).

Threats

Through a variety of effects, climate change potentially represents the greatest threat to the species, at present and in the future. Decreasing spring snow cover duration has been linked to declining Scoter populations in North America, likely due to trophic mismatch, and is likely to also affect Siberian populations (Drever et al. 2011). Ocean acidification could lead to declines in molluscs which form a large part of the Velvet Scoter diet (Steinacher et al. 2009, Carboneras et al. 2020). Another major threat is bycatch in fishing gear, occurring particularly in wintering grounds (Dagys & Hearn 2018). Population declines in the Baltic Sea have coincided with heavy bycatch mortality in gillnet fisheries and Velvet Scoters are amongst the most frequent victims as their foraging ecology puts them at high risk of entanglement (Dagys & Žydelis 2002, Žydelis et al. 2009, 2013, Dagys 2017).

Invasive species pose a threat to Velvet Scoters in parts of the range, but the extent of impacts are largely unknown at present (Almquist et al. 2010, Dagys 2017). Predation from introduced American mink Neovison vison may impair populations on Scandinavian islands (Nordstrom et al. 2002), and the Round Goby Neogobius melanostomus feeds on benthic invertebrates and may impact the abundance and distribution of Scoter food supplies.

During moulting and winter aggregations, the species is highly susceptible to oil spills and other marine pollutants (Gorski et al. 1977, del Hoyo et al. 1992, Kear 2005, UICN France 2011) and one catastrophic oil spill occurring in a key moulting or wintering area could affect a large proportion of the global population (Madge & Burn 1988). Velvet Scoter have been found to be susceptible to avian influenza (Melville & Shortridge 2006) and future outbreaks of disease may be expected and could compound observed declines in parts of its range. The species is also hunted in some areas however, this is generally considered to be sustainable, with annual bags estimated to be between 1,600 and 2,800 individuals in Denmark (Bregnballe et al. 2006). Habitat degradation caused by sand-dredging operations, bottom-trawling fisheries and the installation of wind farms causes the loss, degradation or avoidance of feeding areas (Garthe and Huppop 2004, Skov et al. 2011, Dierschke et al. 2016, Dagys & Hearn 2018), while additional habitat degradation on breeding grounds has resulted from human exploitation of natural resources such as marine benthic organisms and shellfish in the taiga and lower tundra regions (Kear 2005).

Conservation actions

Conservation and Research Actions Underway
Listed on Appendix II of the Convention on Migratory Species (Bonn Convention), Appendix III of the Bern Convention and category 1b of the African-Eurasian Migratory Waterbird Agreement. It is also listed on Annex II Part B of the EU Birds Directive, and as such is a potential game species in certain countries. A draft International Single Species Action Plan (SSAP) has been published (Dagys & Hearn 2018), with a final plan scheduled for publication in 2024. Preceding that an EU Management Plan for 2007-2009 was published. Monitoring is taking place across most countries in the range, but is insufficient in Russia, where the majority breed. Many breeding areas in Europe have protected status, as does a significant area of its marine wintering habitat.

Few targeted conservation actions have been implemented to date, although there has been research into methods to reduce fisheries bycatch: high contrast panels and lights are unsuccessful (Field et al. 2019). Experimental removal of American mink Neovison vison, a nest predator, in the outer archipelago of south-west Finland resulted in an increase in Velvet Scoter breeding density (Nordstrom et al. 2002).

Conservation and Research Actions Proposed
The actions listed here are from the Draft SSAP, where further details can be found. Continue to monitor numbers in both its breeding and wintering range. Of particular importance is the regular implementation of a coordinated mid-winter census across the wintering range and establishing monitoring of breeding success and survival at representative sites across the range. Telemetry studies should be developed to understand movements and identify key sites for different life stages through the year. Clarifying the current breeding distribution and ensuring that sites have adequate protection (for the entire duration of the long breeding season) is also a high priority. Carry out research into the causes of the recently detected decline, in particular regular independent monitoring of by-catch in fisheries is needed to assess the population level-impact of this source of mortality. Continue research aimed at tackling the potential causes of mortality in wintering birds, such as drowning in fishing nets. Assess the sustainability of hunting, especially in Russia.
 
Ensure that the potential presence of Velvet Scoters is taken into account during spatial planning for coastal areas and country EEZs, and ensure potential impacts on the species are explicitly considered at the planning stage for coastal and offshore windfarms. Ensure effective enforcement of regulations applying to the discharge of oil and chemicals, and raise awareness of the threatened status of the species amongst statutory bodies responsible for tackling marine pollution. 

Breeding range states should develop and implement national control plans for non-native carnivores, especially mink Mustela vison.

Identification

51-58 cm. Large Melanitta species, distinguished from M. nigra at long range in flight or when flapping wings by obvious white secondaries forming a square wing bar. Male is blackish and has yellow and black bill, peaking at nostrils, and pale eye with white mark underneath; female is medium to dark brown with paler greyish-brown patches between eyes and bill and adjacent to ear coverts. Males of M. deglandi and M. stejnegeri both have more extensive white patch below and behind eye, and more orange-coloured, distinctively peaked bills, as well as less rounded head shape; females of M. fusca are distinguished from these species by more rounded, frontally-peaked head (see Garner et al. 2004).

Acknowledgements

Text account compilers
Martin, R., Hermes, C.

Contributors
Below, A., Bianki, V., Burfield, I., Ellermaa, M., Grishanov, G., Hario, M., Isfendiyaroglu, S., Kharitonov, S., Kharitonova, I., Kondratyev, A., Kontiokorpi, J., Larsson, K., Lehikoinen, A., Lehikoinen, E., Lehtiniemi, T., Meltofte, H., Mikkola-Roos, M., Morkunas, J., Pessa, J., Petersen, I., Pihl, S., Rajasarkka, A., Tiainen, J., Valkama, J., Ashpole, J, Fjagesund, T., Malpas, L., Moreno, R., Palmer-Newton, A., Stuart, A., Symes, A., Taylor, J., Piggott, A. & Staneva, A.


Recommended citation
BirdLife International (2021) Species factsheet: Melanitta fusca. Downloaded from http://www.birdlife.org on 05/03/2021. Recommended citation for factsheets for more than one species: BirdLife International (2021) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 05/03/2021.