Archived 2020 topic: Velvet Scoter (Melanitta fusca) – reclassify from Vulnerable to Near Threatened

Please note: This discussion topic is one of a set about species that are endemic or nearly endemic to the European Union (EU), and whose status in the EU therefore effectively determines their global status. To ensure consistency between the 2020 global and EU Red List assessments of these species, this set of topics is being fast-tracked through BirdLife’s Globally Threatened Bird Forums to inform decisions on the EU (and global) status of relevant species, which must be finalised and communicated to the European Commission by mid-April 2020. Topics on other species will be posted on the Forums shortly, for discussion later in the spring, as per usual. The results of the 2020 global Red List update for birds will be published by IUCN and BirdLife in early December.

Velvet Scoter Melanitta fusca breeds in Fennoscandia and Russia, east to the River Yenisey and south to Kazakhstan, with isolated populations in the Caucasus; it winters in the Baltic Sea and coastal NW Europe, with some in the Black and Caspian Seas (Carboneras et al. 2020). It is currently listed as Vulnerable under Criteria A2+3+4 (past, future and present declines), because when last assessed its population was thought to be declining at a rate exceeding 30% over three generations (22.5 years, based on a generation length estimated by BirdLife at that time to be 7.5 years).

Globally, it has an extremely large extent of occurrence in both the breeding season (>14 million km2) and in winter (>9,000,000 km2), and hence does not approach the thresholds for Vulnerable under the range size criteria (B and D2). Its population size is also very large (c. 330,000–550,000 individuals; Wetland International 2020), and hence does not approach the thresholds for Vulnerable under the population size criteria (C and D1). Therefore, the only potentially relevant criterion is A, which relates to reductions in population size. When last assessed, the population was thought to be declining by >30% over three generations, based on trend data compiled for the 2015 European Red List (BirdLife International 2015). Many of those data related to the observed reduction in numbers wintering in the Baltic Sea between 1992–3 and 2007–9 (Skov et al. 2011). That assessment was informed by a discussion on this Forum in 2015, when the species’s status was reclassified from Endangered to Vulnerable because its rate of population decline had slowed.

In late 2019, all 28 EU Member States were obliged to complete their second 6-yearly report to the European Commission (EC) under Article 12 of the EU Birds Directive, including their latest information on the sizes and trends of the populations and ranges of all naturally occurring wild bird species. Under an EC contract to evaluate the EU population status of each species, BirdLife has now analysed these new data, which indicate that this species’s wintering population is no longer declining. Trends were assessed over 18.6 years, based on an improved estimate of the species’s generation length (6.2 years; Bird et al. 2020), which supersedes the value used previously.

From a global Red List perspective, the trend of the European wintering population is paramount, since >99% of the global population winters in Europe, and >90% in the EU (BirdLife International 2015). The new winter data reported by EU Member States (totalling 202,000–384,000 individuals) suggest that the population has not only ceased to decline since c. 2007, but has even started to recover from earlier declines and expanded its range in several key countries, especially in the Baltic. Specifically, since c. 2007, Poland (59%) has reported stability, Germany (25%) a large increase (>250%), Denmark (6%) a large increase (400%), and Sweden (2%) a large increase (c. 2000%). Estonia and the United Kingdom have reported short-term declines, while Lithuania and Latvia have reported uncertain/unknown trends – but >90% of the European wintering population is reported as stable, fluctuating or increasing, and the overall trend is increasing.

This new population estimate excludes birds wintering outside the EU, such as in Norway and certain parts of SE Europe and the Caucasus. However, 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. As with some other duck species (Pavón‐Jordán et al. 2018), it is possible that climate change has induced a change in the winter distribution range, allowing some birds to winter farther north and east, such as in the northern Gulf of Bothnia or even the White Sea, which are currently poorly monitored (I.K. Petersen & R. Hearn verbally 2020). However, it is also possible that the c. 60% decline recorded between 1992–3 and 2007–9 (Skov et al. 2011) was driven by a decline in the core Russian breeding population. 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).

During 2016-2017, a Species Action Plan (SAP) for the conservation of Velvet Scoter was developed, through a working group involving experts and stakeholders from across its global range (Dagys & Hearn 2018). The aim of the SAP is restore the Western Siberia & Northern Europe/NW Europe population to a favourable conservation status, by significantly reducing negative anthropogenic impacts on survival and breeding success, and understanding the drivers of decline by 2028. Threats considered most likely to have driven the decline include bycatch of wintering birds in fishing gear, accidental and diffused oil pollution, hunting, predation by non-native species, construction of windfarms and other marine infrastructure developments, disturbance and climate change. Much work remains to be done to implement the SAP and to properly restore the species. The effectiveness of those efforts would be best assessed by more regular internationally coordinated surveys of wintering Velvet Scoters (and other waterbirds), covering as wide a geographical area as possible. Such surveys would not only map their distribution and estimate their numbers and trends, but also detect possible range shifts caused by the effects of climate change. Better monitoring in more northerly breeding areas, particularly in Russia, is also desirable (Dagys & Hearn 2018).

The apparent cessation and partial reversal of declines in the wintering population suggest that whichever factors drove the earlier decline may no longer be having such a negative impact on the species. However, the population remains heavily depleted and far below the levels in the early 1990s, when numbers in and around the Baltic were estimated at around 1,000,000 individuals (Durinck et al. 1994; Scott & Rose 1996). In the EU, M. fusca breeds only in Finland (59%), Sweden (40%) and Estonia (<1%). The new data reveal that the total EU breeding population is relatively small (c. 11,000–24,000 pairs), but declining at a rate of around 30% over three generations, thereby highlighting that the species still faces problems in at least some parts of its breeding range.

Although the species’s Baltic wintering population probably declined by c. 60% between 1992–3 and 2007–9 (Skov et al. 2011), the temporal pattern of that decline is not known, and it is unclear when the decline ceased and the population stabilised, before starting to recover. However, the 18.6 year (three generation length) trend period relevant to this species means that trends since c. 2000 must be considered under Criterion A2 (past declines). That year fell roughly halfway between the two Baltic survey periods, so in the absence of any other information, it seems reasonable to infer that roughly half (i.e. c. 30%) of the recorded decline took place after 2001. The overall increase recorded since 2001 has partially offset that decline, but the ongoing decline in the EU breeding population, and uncertainty about the current Russian trend, make it reasonable to infer that the overall decline over the last three generations (c. 2000–2019) may still have approached 30%. This warrants a reclassification of the species’s status, from Vulnerable to Near Threatened under Criterion A2b (past declines). It is not possible to invoke Criteria A3 and A4, as the species is no longer declining.

Relevant comments and information on this fast-track topic are welcome by 8 April 2020, please.

Please note that this forum topic is not designed to be a general discussion about the ecology of the species, but rather a discussion of the species’s Red List status. Therefore, please ensure your comments are relevant to the species’s Red List status and the information requested. By submitting a comment, you confirm that you agree to the BirdLife Forums’ Comment Policy.

References

Bird, J.P., Martin, R., Akçakaya, H.R., Gilroy, J., Burfield, I.J., Garnett, S., Symes, A., Taylor, J., Şekercioğlu, Ç.H. & Butchart, S.H. (2020). Generation lengths of the world’s birds and their implications for extinction risk. Conservation Biology. https://doi.org/10.1111/cobi.13486

BirdLife International (2015) European Red List of Birds: Velvet Scoter Melanitta fusca. http://datazone.birdlife.org/userfiles/file/Species/erlob/summarypdfs/22724836_melanitta_fusca.pdf

Carboneras, C., Kirwan, G.M. & Sharpe, C.J. (2020) Velvet Scoter (Melanitta fusca). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. https://www.hbw.com/node/52922

Dagys, M. and Hearn, R. (compilers) (2018) International Single Species Action Plan for the Conservation of the Velvet Scoter (Melanitta fusca): Western Siberia & Northern Europe/NW Europe population. AEWA Technical Series No. XX, Bonn, Germany. http://www.trackingactionplans.org/SAPTT/downloadDocuments/openDocument?idDocument=35

Durinck, J., Skov, H., Jensen, F.P. and Pihl, S. (1994) Important Marine Areas for Wintering Birds in the Baltic Sea. EU DG XI research contract no. 2242/90-09-01. Ornis Consult report.

Krivenko, V.G. and Vinogradov, V.G. (2008) Ptitsy vodnoi sredy i ritmy klimata Severnoi Evrazii (Birds of the Aquatic Environment and Climate Rhythms of Northern Eurasia), Moscow: Nauka.

Pavón‐Jordán, D., Clausen, P., Dagys, M., Devos, K., Encarnaçao, V., Fox, A.D., Frost, T., Gaudard, C., Hornman, M., Keller, V. and Langendoen, T., 2019. Habitat‐and species‐mediated short‐and long‐term distributional changes in waterbird abundance linked to variation in European winter weather. Diversity and Distributions25(2), pp.225-239.

Scott, D.A. and Rose, P.M. (1996) Atlas of Anatidae populations in Africa and western Eurasia. Wetlands International.

Skov, H. et al. (2011) Waterbird populations and pressures in the Baltic Sea (Vol. 550). Nordic Council of Ministers.

Voltzit & Kalyakin (2019) Database of the project on Atlas of Breeding Birds of European Russia. Wetlands International (2020) Waterbird Population Estimates: wpe.wetlands.org

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14 Responses to Archived 2020 topic: Velvet Scoter (Melanitta fusca) – reclassify from Vulnerable to Near Threatened

  1. In Cape Põõsaspea, NW-Estonia the autumn 2019 total of Velvet Scoters Melanitta fusca was 9 % lower than in 2014 (74244 vs 67387 on passage), mainly because of lower breeding success in 2019. The number of adult males was similar to that of 2014 when modelled. The autumn totals have been rather stable over last 15 years. (Ellermaa & Lindén 2020, manuscript submitted). In Põõsaspea, more or less only breeders of Western Russia occur. The population of Baltic Sea is suffering, but other guys will comment on that I suppose.

  2. Daniel Bengtsson says:

    The proposal for the Swedish Red List is going the opposite way, i.e. from NT to VU (same as Finland?). The Swedish breeding population decline is estimated to 32% over three generations (21 years). The number of reproductive individuals is estimated to 14 200 (+- 2000). The decline is believed to depend on the quality of habitat (negatively effected by eutrofication of the Baltic Sea) and reduction in number of reproductive individuals (oil spills and increased mortality from e.g. boats and American mink, possibly also shortage of tiamine).

  3. I wonder how the trend was calculated over three generations and based on what data. If we take the generation length recommended by BirdLife – 7.5 years, it will be about 23 years, so the trend should be calculated for the period of 1996-2019 and for 6.2 years 2000-2019. What we have is the estimate for the early 1990s – 1,000,000 individuals (Durinck et al. 1994, Delany & Scott 2006), then we have the estimate for 2007-2009: 450,000–500,000 individuals (Wetlands International 2016) and currently 330,000-550,000 (Wetland International 2020). The justification for lowering the status to NT is not fully clear to me.
    I don’t think we have good data from 1995-2000, but we can do a simple calculation. Therefore, if we do not know the numbers at a given moment (e.g. in 1996 or in 2000), we can estimate it based on data from the beginning of 1990 and 2007-2009 assuming a stable downward trend in this period. Then it turns out that in 1996 the number can be estimated at 820,000, and 2000 at 700,000 individuals. It follows that the decrease in numbers in these time windows was 47% (1996-2019) and 37% (2000-2019). So, both taking into account the length of generation 7.5 and 6.2 years, the decline still qualifies this species in the VU category.

  4. Nele Markones says:

    I agree that the recent trends in the most important wintering areas can be summarized as stable or increasing but these refer to a shorter period (12 years). It’s critical to get a good idea on the declines before that to judge whether the overall rate of change for the last 3 generation lengths exceeds 30% or not. Based on the details you give, it is not possible for me to follow your assumptions. It would be helpful if you could provide precise values for the calculations in your last paragraph since that seems to be the most critical part here. The assumed 30% decline after 2000 refers to a reference value outside your 3 generation length period. It is unclear which value you take as the baseline for 2000.
    Besides, 2000 might not be the correct staring point for your assessment period.
    The new population estimates from the recent Art 12 BD refer to a mean for 2011-2016 (not for 2019).

  5. Sureyya Isfendiyaroglu says:

    Although this would have a minor impact on the global assessment. The tiny breeding population in Turkey, which was part of the Caucasus Population, had been surveyed by WWF-Turkey and Kuzey Doga Association. No evidence of breeding was found in Turkey and the species was reported to have gone extinct in Turkey, in Turkish Breeding Bird Atlas Report. The number of wintering individuals in Black sea, have dropped dramatically in the last two decade. I don’t think the rest of this tiny population’s doing fine.

  6. Julius Morkunas says:

    In Lithuania Velvet Scoter in coastal areas up to 20m depth is still declining. Basically major threat is bycatach in gillnet fishery. Last year the species was put to Lithuanian Red List together with Long-tailed Duck.

  7. Velvet Scoter, like few other species in this group, is highly mobile during the non-breeding period, both in terms of differences between seasons and displacements during one winter season. Therefore, we should carefully check trends in individual countries in different time windows. For example, the trend in Poland (the country where most of the species’ population winters) was downward for the period 2011-2017 (Chylarecki et al. 2018). The German national increasing trend reported for the Art 12 report refers to 2004-2016 – so the increases in German waters (and the Danish and probably also Swedish) can be fully explained by the parallel declines in Polish waters and thus a distribution shift and not a true increase.

  8. Yann Rouxel says:

    A brief on the UK population too – hopefully it helps:

    UK population is very small in comparison to the Baltic context (only about 3,400 individuals according to Frost et al. 2019 and Woodward et al. 2020), and only non-breeding.
    Frost et al. (2019) estimated a slight increase in the wintering population for the period 2012/13 to 2016/17; though the reason for such change is estimated to be “improved knowledge or more accurate data”, not necessarily a genuine change [https://app.bto.org/webs-reporting/]. This is also limited given the very short period considered, largely influenced by a peak in records in 2015/16. Current record (2018/19) is similar (or lower) to what was observed a decade ago. Over three generations (approximately since 2000 till now), the trend is quite unclear with two peaks of the population index in 2002/03 (especially) and in 2015/16, while the rest of the time 2006-to-2015 and recent years (from 2017) are showing a more stagnating low trend (or even decreasing if last years’ decrease continues). Finally, important to note that only inshore data (observed from shore) are included in the WeBS UK index (i.e. no offshore data from e.g. aerial surveys), thus data gap still might exists.
    Nonetheless, a recent review on the risk of extinction of birds in Great Britain (UK minus Northern Ireland), listed Velvet Scoter as Vulnerable using IUCN criteria (Stanbury et al. 2017). Also, a climate change risk assessment for waterbirds species in the UK, projected for the Velvet Scoter population (Non-breeding) to experience a “Moderate decline” in the future (Burton et al. 2020).
    I am not an expert in population trends and assessments, but it seems that there is no clear increase of the non-breeding population in the UK, at best is stagnating, and could even be decreasing (if the recent years trend is confirmed) and with the additional effect of climate change over the next decades. At least for the UK context, and similarly to the Baltic experts, I believe the species still should be listed as Vulnerable (but again I am not an expert and maybe this falls under IUCN red list requirements still).

    [thanks to the Wildfowl & Wetlands Trust which pointed me to the relevant studies and refs.]
    – Frost, T., Austin, G., Hearn, R., McAvoy, S., Robinson, A., Stroud, D., … & Wotton, S. (2019). Population estimates of wintering waterbirds in Great Britain. British Birds, 112, 130-145.
    – Woodward, I., Aebischer, N., Burnell, D., Eaton, M., Frost, T., Hall, C., Stroud, D.A. & Noble, D. (2020). Population estimates of birds in Great Britain and the United Kingdom. British Birds 113: 69–104.
    – Stanbury, A., Brown, A., Eaton, M., Aebischer, N., Gillings, S., Hearn, R., … & Gregory, R. (2017). The risk of extinction for birds in Great Britain. British Birds, 110(9), 502-517.
    – Burton, N.H.K., Austin, G.E., Frost, T.M. and Pearce-Higgins, J.W. (2020) Impacts of climate change on UK’s coastal and marine waterbirds. MCCIP Science Review 2020, 400–420.

  9. Nele Markones says:

    I support Dominik’s comments. It is reasonable to assume that the past population reduction over the 3 generation period exceeds 30%.
    If I understood the last paragraph of the discussion correctly, it was assumed that half of the 60% reduction between 1992–3 and 2007–9 had taken place after 2000. If so, that would correspond to a decline of ~43% in the period 2000-2007/9 (the 30% refer to the initial baseline value of 1.000.000 from 1992-3). The following strong increases in wintering numbers in recent years were reported by countries with lower shares of the Baltic Sea wintering population (DK, DE and SE) and were opposed by continuing declines in Lithuania and Poland (hosting >60% of the wintering numbers) as we have now learnt from Julius and Dominik. It is thus rather unrealistic that the previous strong declines have actually been offset.
    Comparing the assumed estimate for 2000 of ~700.000 wintering birds in the Baltic Sea (see Dominik’s first post and following the assumptions in the last paragraph of the discussion, see above) with the new winter data reported by EU Member States (totalling 202,000–384,000 individuals), the deduced reduction over the 3 generation length amounts to 45-70%.

  10. Szabolcs Nagy says:

    Population estimates from off-shore winter surveys should be interpreted with great caution and it is not really justified to compare them on face value (as in Skov et al., 2011) and the subsequent WPE and CSR assessments of Wetlands International. The validity of calculating population trends from national trends for fixed periods is also doubtful especially for wintering birds whose distribution can shift to a large extent to year-to-year. Just take the 400% increase reported for Sweden in the Article 12 report. If you go back to the source (Nilsson and Haas, 2016, but also in Haas and Nilsson, 2018), you will see a decline between 1970 to 2011 and then a sudden jump, which is probably not linked to a recovery of the population (as that level of increase would be biologically impossible), but to changes in weather conditions and the associated shift in distribution. Therefore, it is better to base the assessment of trends on annual indices at international level produced by Wetlands International (2017) or HELCOM (2017). The former, reports a large decline between c. 1997 and 2015, but most of the years are imputed. However, this trend is very much influenced by missing data from Lithuania. If we exclude the data from Lithuania, the trend is uncertain with a declining tendency until 2010, followed by some suspiciously rapid recovery. If I look at the result of the Baltic Sea trend analysis (HELCOM, 2017), a similar pattern emerges a large decline between the mid-1990s and early 2000s, followed by a gradual recovery, qualifying for a moderate decline. As nearly 80% of the breeding population breeds in Russia with an unknown trend, I would concur with the proposal to classify the species as NT.

    • Nele Markones says:

      Absolutely right, the evaluation of population trends of species like Velvet Scoters should ideally be based on synchronized large-scale assessments rather than separate national assessments.
      However when it comes to assessments based on land-based waterbird counts, it has to be noted that Velvet Scoters is one of the species that is (at least in some regions) not covered well by coastal counts due to the species concentrating in offshore waters far from the coast. E.g. in Germany, 99% of wintering Velvet Scoters occur outside the IWC survey area (FTZ, Kiel University, unpublished). In this case, weather conditions can have a strong effect on results of waterbird counts like you mentioned.
      The preliminary HELCOM 2017 assessment referred to here was predominantly based on mid-January IWC counts. At the subsequent evaluation of the assessment, the HELCOM bird experts expressed their concern about the reliability of these results for offshore species. The meeting decided to exclude those species from the final HELCOM HOLAS II assessment, which do not occur in representative proportions in coastal waters and thus cannot be reliably assessed with IWC data only (ICES 2018). The species mentioned include Velvet Scoter alongside other seaducks, grebes and divers.
      To be complete, the national trends derived by Poland (hosting the majority of Velvet Scoters, negative trend until 2017) are based on annual offshore line transect counts covering the concentration areas of Velvet Scoters. In the same period, numbers in Germany (also based on regular offshore line transect surveys) increased but increases here do not offset the reductions in PL (reduction by 50.000 ind. between the two Art 12 reports vs. increase of 28.000 in DE).

  11. Red List Team (BirdLife International) says:

    The following comment is posted on behalf of Jula Selmani (National Agency of Protected Areas, Albania):

    Velvet Scooter, is a rare winter visitor in Albania due to the species normal range of occurrence. We consider this species to be excluded from evaluation for the National RedList of Albania.

  12. Red List Team (BirdLife International) says:

    Many thanks to everyone who has contributed to this discussion over the past 10 days. We realise that the window for consultation was short (and is now closed), and greatly appreciate the time and effort invested by so many people in commenting, especially during this unprecedented time globally. The volume and variety of responses received on this (and other) species means that it will take us several more days to digest, analyse and interpret everything. We will however do so as quickly as possible, posting our considered conclusions on this species’s status on this page in a final contribution by mid-April.

    Thank you once again, and Happy Easter.

    BirdLife Red List Team

  13. Red List Team (BirdLife International) says:

    Following careful review and consideration of the existing available information, as well as the new information and valuable views shared through the consultation above, we have now reached a decision on the status of this species for both the 2020 global Red List and the EU Red List of birds. Our conclusion is that this species should be precautionarily classified as Vulnerable (A2abcde) – retaining its current classification, rather than being reclassified as Near Threatened as originally proposed.

    This decision takes into account the uncertainty around the precise spatio-temporal trend of the species’s population, and acknowledges the possibility that it may have declined by more than 30% over the last three generations. It also reflects the mobility of the species and the fact that its winter distribution appears to have shifted in recent years (possibly due to climate change), potentially exaggerating the extent of the perceived recent stabilisation and potentially the start of a recovery. The recent decline of the small EU breeding population, and the unknown trend of the large Russian breeding population, provide further justification for taking a precautionary approach. However, we are not persuaded that there is sufficient evidence to continue invoking an ongoing or future overall decline exceeding 30% over three generations – hence, we are not retaining A3 or A4 at the Vulnerable level (although they could be invoked at the lower level of Near Threatened).

    In acknowledging this uncertainty, we encourage relevant parties to collaborate on more regular internationally coordinated winter surveys of this and other species in and around the Baltic, with the aim of reaching broad consensus on an overall population estimate and trend in time for the next round of Article 12 reporting in 2025. Such collaboration would increase the amount of reliable information available on this species, and thereby help to inform its conservation and management (through the implementation of the Species Action Plan), as well as future status assessments.

    Many thanks once again to everyone who contributed to the discussion above and helped to inform this outcome. The 2020 Red List update for birds including this assessment will be published on the BirdLife and IUCN websites in December.

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