Archived 2011-2012 topics: Taxonomic changes in the genus Melanitta, part II: suggestions to list M. fusca as Endangered and M. deglandi as Least Concern, and request for information on M. stejnegeri

Initial deadline for comments: 31 January 2012.

BirdLife species factsheet for White-winged Scoter (prior to the taxonomic change)

White-winged Scoter Melanitta fusca has been split into M. fusca, M. deglandi and M. stejnegeri following a review of recent literature (Livezey 1995, Garner et al. 2004, Sangster et al. 2005, Collinson et al. 2006, AOU 2010) and museum specimens by the BirdLife Taxonomic Working Group. Prior to this taxonomic change, the polytypic species M. fusca was listed as being of Least Concern on the basis that it was not thought to approach the thresholds for Vulnerable under any of the IUCN criteria.

Following the taxonomic change, all three species are still regarded as having extremely large ranges and hence do not approach the thresholds for Vulnerable under the range size criteria (B and D2: EOO of less than 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). Their population sizes are also large (probably >500,000 individuals in M. deglandi, which has the smallest population; Wetlands International 2006), and hence do not approach the thresholds for Vulnerable under the population size criteria (C and D1: fewer than 10,000 mature individuals with a continuing decline estimated to be at least 10% over ten years or three generations, or with a specified population structure).

Therefore, the only relevant criterion is A, which relates to reductions in population size. Until recently, there was little evidence to suggest that any of these taxa were declining sufficiently rapidly to approach the threshold for listing as Vulnerable under criterion A (at least a 30% decline over ten years or three generations, whichever is longer).

M. fusca
This species breeds in Scandinavia and western Siberia to the River Yenisey, and winters mostly in the Baltic Sea and along the coasts of Western Europe (c.1 million birds; Wetlands International 2006), with only an estimated 1,500 birds wintering in the Black Sea and Caucasus (Wetlands International 2006). Since surveys in 1992-1993, when the estimate of the north-west European wintering population of M. fusca was updated to c.1 million birds, an apparent decline of c.60% (3.7% annually) has been 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). Extrapolation of the data implies that this is equivalent to a decline of c.77% over three generations, estimated at 23 years (based on a generation length of c.7.5 years; BirdLife International unpubl. data).

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 seems 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 rapid decline has probably taken place. This is supported by reports of probable declines elsewhere in its range, e.g. in the UK (Holt et al. 2011)

It is possible that the lower numbers recorded in the Baltic (and possibly elsewhere in north-western Europe) relate not to a population decline, but to changes in the species’s winter distribution. In recent decades, many waterfowl species have responded to global climate change by ‘short-stopping’, i.e. taking advantage of warmer conditions to winter closer to northern breeding areas than was previously possible. M. fusca may have been affected by this phenomenon, and there is some evidence for a partial northwards shift in the species’s distribution within the Baltic (Skov et al. 2011). However, this is not capable of explaining the whereabouts of the c.600,000 birds ‘missing’ from the Baltic. It is possible that some birds may now be wintering in the White Sea or Barents Sea off north-western Russia, but there is no evidence for this.

Assuming therefore that the decline recorded in the Baltic is genuine, then globally the species may be declining at a rate of more than 70% over three generations, which would qualify the species for uplisting to Endangered under criterion A. Comments would be welcomed.

M. deglandi
This species breeds in Canada, Alaska and the very north of the contiguous United States, and winters mainly off both the Atlantic and Pacific coasts of North America, reaching farther south than when breeding. Most indices have indicated population declines; however, it has not been possible to reliably estimate the magnitude of the declines (Sea Duck Joint Venture 2003). The species is said to have declined nearly to the point of extirpation in the prairie biome. However, the number of birds formerly occupying this portion of the range cannot be estimated. Data from the US Fish and Wildlife Service–Canadian Wildlife Service breeding waterfowl survey indicate that the combined population of all three scoter species along survey transects in the western boreal forest may have declined by as much as 75% since the 1950s. However, it is not possible to separate trends specific to M. deglandi and the magnitude of the decline for this species cannot be ascertained. Trends have not been apparent in other parts of the species’s breeding range. Mid-winter inventory data do not indicate any trends on the Pacific coast and only weakly show a decline on the Atlantic coast. However, these surveys are said to track scoter populations poorly and all three species are combined in one count (Sea Duck Joint Venture 2003). Contrary to many other studies, analysis of Christmas Bird Count data overall indicates an annual increase of 1.20% between 1965-1966 and 2005-2006 across about half of its range (Butcher and Niven 2007), implying that this species may in fact qualify as Least Concern. Comments would be welcomed.

M. stejnegeri
This species breeds in central and eastern Siberia east of the River Yenisey, and winters along the coasts of East Asia. It is estimated to number 600,000-1,000,000 birds; however, population trends are apparently unknown (Wetlands International 2006). Information is requested on this species’s population trends to assist in the assessment of its threat status against criterion A.

Further information is requested and comments are invited on whether the population of M. fusca is likely to have declined at a rate equivalent to 50-79% over the past three generations, and thus whether it qualifies for listing as Endangered under criterion A. Under the same criterion a decline of at least 30% over three generations would qualify the species for Vulnerable, while a decline approaching 30% (typically 20-29%) would qualify the species for Near Threatened. Comments are also invited on the potential listing of M. deglandi as Least Concern.

References:

American Ornithologists’ Union (2010) Fifty-first Supplement to the American Ornithologists’ Union Check-list of North American Birds. Auk 127: 726-744.

Butcher, G. S. and Niven, D. K. (2007) Combining Data from the Christmas Bird Count and Breeding Bird Survey to Determine the Continental Status and Trends of North American Birds. Ivyland, PA: National Audubon Society.

Collinson, M., Parkin, D. T., Knox, A. G., Sangster, G. and Helbig, A. J. (2006) Species limits within the genus Melanitta, the scoters. British Birds 99: 183-201.

Garner, M., Lewington, I. and Rosenberg, G. (2004) Stejneger’s Scoter in the Western Palearctic and North America. Birding World 17: 337-347.

Holt, C. A., Austin, G. E., Calbrade, N. A., Mellan, H. J., Mitchell, C., Stroud, D. A., Wotton, S. R. and Musgrove, A. J. (2011) Waterbirds in the UK 2009/10: The Wetland Bird Survey. Thetford, UK: BTO/RSPB/JNCC.

Livezey, B. C. (1995) Phylogeny and Evolutionary Ecology of Modern Seaducks (Anatidae: Mergini). Condor 97: 233-255.

Sangster, G., Collinson, J. M., Helbig, A. J., Knox, A. G. and Parkin, D. T. (2005) Taxonomic recommendations for British birds: third report. Ibis 147: 821-826.

Sea Duck Joint Venture (2003) Species status report. http://www.seaduckjv.org/meetseaduck/species_status_summary.pdf

Skov, H., Heinänen, S., Žydelis, R, Bellebaum, J., Bzoma, S., Dagys, M., Durinck, J., Garthe, S., Grishanov, G., Hario, M., Kieckbusch, J. K., Kube, J., Kuresoo, A., Larsson, K., Luigujoe, L., Meissner, W., Nehls, H. W., Nilsson, L., Petersen, I. K., Roos, M. M., Pihl, S., Sonntag, N., Stock, A. and Stipniece, A. (2011) Waterbird Populations and Pressures in the Baltic Sea. TemaNord 2011: 550. Copenhagen, Denmark: Nordic Council of Ministers.

Wetlands International (2006) Waterbird population estimates. Fourth edition. Wageningen, The Netherlands: Wetlands International.

The following input from Dr. Gennady Grishanov was forwarded to us on 30 January 2012: Melanitta fusca Grishanov Jan12

The following letter was received on 31 January 2012: Melanitta fusca Lehikoinen et al. Jan12

Related posts:

  1. Archived 2011-2012 topics: Taxonomic changes in the genus Melanitta, part I: suggestion to list M. nigra as Vulnerable and request for information on M. americana
  2. Archived 2011-2012 topics: Semipalmated Sandpiper (Calidris pusilla): request for information
  3. Archived 2011-2012 topics: Baer’s Pochard (Aythya baeri): request for information
  4. Archived 2011-2012 topics: Orange-breasted Falcon (Falco deiroleucus): request for information
  5. Archived 2011-2012 topics: Hooded Grebe (Podiceps gallardoi): does it qualify as Critically Endangered?
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10 Responses to Archived 2011-2012 topics: Taxonomic changes in the genus Melanitta, part II: suggestions to list M. fusca as Endangered and M. deglandi as Least Concern, and request for information on M. stejnegeri

  1. Ian Burfield says:

    Melanitta fusca is listed as nationally Endangered in the 2011 update of the Red List of the birds of France:

    “France is located on the southern edge of this species’s regular wintering range. It occurs in small groups of several dozen individuals on the French coast between October and April. However, few areas are used regularly, with the most important being focused on the Normandy coast. With fewer than 1000 individuals wintering in total, the national population of this species has been declining since the 1990s. Marine pollution, especially caused by oil, is considered to be one of the main threats to the species, and climate change may also affect its presence in France. For these reasons, it is is classified as nationally Endangered.”

    Source: UICN France, MNHN, LPO, SEOF & ONCFS (2011). La Liste rouge des espèces menacées en France – Chapitre Oiseaux de France métropolitaine. Paris, France. http://www.uicn.fr/IMG/pdf/Liste_rouge_France_Oiseaux_de_metropole.pdf

  2. Breeding population of White-winged Scoter (WwS) has decreased in Finland about 30 % in 10 years (from about 15000 pairs to 10000 pairs; Rassi et al 2010). However, it was listed in 2010 only as Near Threatened (not Vulnerable, which should had been triggered according generation length criterium).

    In autumn monitoring (full seasons) 2004 and 2009, in Põõsaspea Cape, there was no decreasing trend in abundance of passing WwS (n = 52300 and 60500). The differences in reproduction success of those years didn’t explain the differences in numbers (poor reproduction in both years, Ellerma & al 2010).

    There has been long term decreasing autumn trend of migrating WwS in Hanko Bird Station (Lehikoinen & al 2008), about 50 % in 30 years. But decrease stopped about 1995. No trend was observed in springs. However, Hanko is at very border of Russian WwS population flyway and sample size per year is very small.

    Breeding population of Estonia had very negative trend between 1970-1990. No trend was observed 1991-2007 (400-700 pairs, Elts & al 2008). However data is with low quality for latter trend. The WwS is not red listed there (review in 2008).

    After all, that big recent collapse of WwS according Skov et al (2011) has not that well confirmed by data presented above. I can prove it wrong neither. However seems, that there was maybe reason to red list the WwS already in 1990′es.

    References
    - Ellermaa, M., Pettay, T. & Könönen, J. 2010: Autumn migration in Põõsaspea Cape in 2009. Hirundo 23:21-46.
    - Elts, J. & al 2009: Eesti lindude staatus, pesitsusaegne ja talvine arvukus 2003–2008. – Hirundo 22:3-31.
    - Lehikoinen, A. (toim.), Ekroos, J., Jaatinen, K., Lehikoinen, P., Lindén, A., Piha, M., Vattulainen, A. & Vähätalo, A. 2008: Lintukantojen kehitys Hangon lintuasemalla 1979–2007. Bird population trends based on the data of Hanko Bird Observatory (Finland) during 1979–2007. — Tringa 35: 146–209.
    -Rassi, P., Hyvärinen, E., Juslén, A. & Mannerkoski, I. (eds.) 2010: The 2010 Red List of Finnish Species. – Ministry of the Environment
    Finnish Environment Institute.

  3. Nial Moores says:

    Asian Waterbird Census data would likely provide the most-informed insights into the distribution and abundance of “Snub-nosed Scoter” M. stejnegeri (what English name will be used?) overwintering in East Asia.

    Within the Republic of Korea (ROK), there are no robust, long-term datasets which can be used to identify national population trends. However, an analysis of soft data contained within historical literature (Moores 2011) suggests that M. stejnegeri has probably declined since the time of Gore & Won (1971). They described the species as a “Common winter visitor on the east and south coasts; rare on the west coast”. During the present century, the species appears to be uncommon and rather local, and probably decreasing (at least locally). An increase in coverage of areas used by the species in the ROK during the annual land-based midwinter bird census (conducted under the auspices of the Ministry of Environment since 1999) likely contributed towards an increased number of M. stejnegeri recorded during the past decade (only 135 in 2000 and 1072 in 2010: MOE Census 2000, 2010), in contrast to the lower number of American Scoter recorded the same years. However, in 2000-2001 >1000 were present several km offshore from the Nakdong Estuary (feeding close to floating mariculture platforms) and were left unrecorded by MOE Census 2000. This flock was either much reduced in size or was no longer extant by 2010 (Birds Korea unpublished data). Medium-sized flocks elsewhere in the south-east and along the east coast also appeared to be much reduced in number in 2009-2011 compared with 2000 & 2001 (Birds Korea unpublished data). In the ROK part of the Yellow Sea, including along the west coast, the species also appears to be local, with most records from close to 37°N, within 5km of land. The highest count made during a total of 150 journeys on high-speed vessels of opportunity along three transects between 2000 and 2010, was only of 20 along the northern transect (north of 37°N), with zero recorded along either the central transect (close to 35°N) or the southern transect (34°N) (Moores 2011). A peak of 53 was recorded during monthly counts of seabirds from Socheong Island (37° 45′ N, 124° 44′ E) in 2009/2010, suggesting that substantial numbers might overwinter along presumably largely inaccessible rocky coasts of the closely-adjacent DPRK. However, to date our data do not yet support the suggestion that the species winters “extremely commonly” along the west coast of Korea (Pihl & Fox 2005).

    References
    Gore, M. & Won P-O. 1971. The Birds of Korea. Published by the Royal Asiatic Society.
    Ministry of Environment (MOE). 2000, 2010. Winter Bird Census (in Korean).
    .Moores, N. 2011. The Distribution, Abundance and Conservation of the Avian Biodiversity of Yellow Sea habitats in the Republic of Korea. Doctoral thesis, University of Newcastle, Australia.
    Pihl, S. & T. Fox. Velvet Scoter Melanitta fusca. Pp. 715-719 in Kear (ed.), Ducks, Geese and Swans. Volume 2: Species Accounts (Carinia to Mergus). Bird Families of the World. Oxford University Press.

  4. Jari Kontiokorpi says:

    General from Vyborg, view my comment in Long-tailed Duck.
    http://www.birdlife.org/globally-threatened-bird-forums/2011/11/long-tailed-duck-clangula-hyemalis-uplist-to-endangered/

    Velvet Scoter use normally more southeastern route than Vyborg Bay, the migration route on the edge of whether seems much seen in the figures. For comparison In Repino near St Petersburg (almost 100 km ESE from Vyborg), we saw 1992-2001 in 211 hours in average 630 Velvet Scoter/observed hour (N=133000), in Vyborg 1988-2008 in 2400 hours in average 79 ind./observed hour. Best Velvet Scoter number in one day in Repino was 48000 (16.5.95), in Vyborg 13000 (9.5.1993). Unfortunately observation in Repino has been too limited; in fact only 1994-95 observation was quite regular.

    In Vyborg Velvet Scoter´s amounts have been decreasing: in 1988-94 we counted in average 130 ind./observed hour, in 1995-99 55 and 2000-2008 53 ind. (N=190 000), but in this case we must remember that the margin of error can be big.

    • Jari’s data confirms my suspection above (January 11), that the collapse of White-winged (Velvet) Scoter happened already by 1995 and redlisting is maybe 15 years late.

  5. It seems that distribution shift could have taken place not only in wintering areas and migration routes, but also on breeding grounds. In mid 90-ies Velvet Scoter was only noticed as rare summer visitor to Kolguev island (Barentz Sea), with no known breeding records (Morozov, Syroechkovsky, 2004). Since 2006 we have it as a regular breeding species, with good density of broods (2/10 sq.km) in their favorite habitats.

  6. Joe Taylor says:

    The following comments by Dr. Sergei P. Kharitonov were forwarded to us on 30 January 2012:

    Two extensive tundra areas were monitored in the western half of Taimyr: 1) in 2004, 2007, 2010 at the central Taimyr we surveyed near 400 km of the Agapa River streams, from the southernmost Red-breasted Goose colony (70.11N, 86.15E) up to the river mouth (71.26N., 89.13E); 2) in 2000-2007 at the northern Taimyr, Medusa Bay area we monitored 380 sq. km area near the Willem Barents Station (73.23N, 80.32E), including lower streams of the Lemberova, Maximovka and Efremova Rivers and part of the Kara Sea coast.

    1) In the north-west Taimyr, Medusa Bay area only Long-tailed Duck is common staging and breeding bird. Numbers are fluctuating with slight trend to decrease. Years of very low numbers – 2003 and 2007 (flock of several staging birds), usual numbers are – flocks of 10-20 staging birds
    Black Scoter – occasional bird, usually singles very rare can be observed, one time in 2001 flocks of 10 birds was recorded
    Velvet Scoter – occasional bird, singles. In 2003 surprisingly was registered 100 birds, then does not seen in 2004-2007.

    2) Agapa River area – all four duck species are present. Long-tailed duck breeding, it is the most common duck in that area, however numbers ids not high – first hundreds bird per the 400 km river stream.
    Great scoup – numbers is low, several tens of birds per 400 km river stream
    Black Scoter – rear duck, decreasing in numbers over 2004-2010
    Velvet Scoter – rear duck – several tens per 400 km of the Agapa river streams, numbers trend is unclear.

  7. Here are comments for the 2012 IUCN Red List update proposal from the Finnish expert group on birds, which did the evaluation for the last national Red List (2010). Our comments concern four duck species: the Scaup Aythya marila, Long-tailed duck Clangula hyemalis, Velvet scoter Melanitta fusca and Common scoter Melanitta nigra. We have used Finnish breeding censuses (nest counts and breeding atlas) and migration counts as sources of conclusions. We must point out that the migration count analyses are quite harsh, since there was not enough time for detailed analyses. Nevertheless, we believe that the trends that they show indicate real changes in the population sizes, but we should not put too much weight on the exact magnitude of change especially in the uncommon Scaup and Velvet scoter.

    Best wishes,

    Antti Below, Finnish Forest and Park Service, Metsähallitus
    Martti Hario, Finnish Game and Fisheries Institute
    Aleksi Lehikoinen, Finnish Museum of Natural History
    Esa Lehikoinen, University of Turku
    Markku Mikkola-Roos, Finnish Environment Institute
    Jorma Pessa, Centre for Economic Development, Transport and the Environment, Oulu
    Ari Rajasärkkä, Finnish Forest and Park Service, Metsähallitus
    Teemu Lehtiniemi, BirdLife Finland
    Juha Tiainen, Finnish Game and Fisheries Institute
    Jari Valkama, Finnish Museum of Natural History

    Melanitta fusca (IUCN recommendation EN)
    The Finnish breeding population along the Baltic coast about halved during 1986–2010 (annual population growth rate 0.96, Hario & Rintala 2011). The total estimated population size in the coastal areas in 2010 was 5200 pairs. There is also a small breeding population (less than 1000 pairs) in northern Finland, but it has not been monitored as well as the coastal one. However, both areas show a decrease in distribution between the 1970s–1980s’ and the 2000s’ atlases (572 and 471 grids, respectively).
    The migration numbers along the migration flyway of the Gulf of Finland have dropped. Migration in the eastern Gulf of Finland (Vyborg) has been declining by about 65% during the last two decades, i.e. from a mean of 130 individuals/observation hour in 1988–1994 (n = 762 hours) to 53 ind./hour in 2000–2008 (n = 628 hours) (total n = 190 000 birds).
    The smaller data sets comes from the Söderskär station (site description see Hario et al. 2009, numbers unpublished), which is situated north from the main migration route of Velvet scoters. Nevertheless, numbers have been decreasing since 1980s.

    Both the Finnish breeding data and the Finnish–Russian migration data support the declining population trend and unfavourable population status.

    References:
    Hario, M. & Rintala, J. 2011: Population trends of the archipelago birds along the Finnish coasts during 1986-2010. Linnut-vuosikirja 2010: 40-51.
    Valkama, J., Vepsäläinen, V. & Lehikoinen, A. 2011: The Third Finnish Breeding Bird Atlas. – Finnish Museum of Natural History and Ministry of Environment. http://atlas3.lintuatlas.fi/results/species/velvet%20scoter

  8. Joe Taylor says:

    The following comments by Dr. Vitaly V. Bianki and Irina A. Kharitonova were forwarded on 30 January 2012:

    Study area: Kandalaksha State Nature Reserve, head of Kandalaksha Bay, the White Sea.

    Melanitta fusca. Breeding and moulting. For the recent decade the numbers decreased about four-fold, breeding as well as moulting birds.

  9. Tim Bowman (U.S. Fish and Wildlife Service) has provided the following information:

    Indices of scoter abundance obtained during the North American Breeding Waterfowl Survey combine all scoters into a single group, but the long term (1950s to present) trend is decidedly downward in the survey strata where white-winged scoters and surf scoters predominate, primarily in western Canada and Alaska. The western North America wintering population is roughly estimated at 100,000 – 200,000 birds. In eastern North America, the wintering population is estimated at about 40,000 – 50,000 birds, but there is little information on long-term trends due to lack of comprehensive surveys and lumping of scoters into a single group, which precludes single-species assessments. Data from the eastern survey area of the North American Breeding Waterfowl Survey suggest that scoter numbers have been stable since 1990, when that area was added to the survey.
    No reliable (long term, large scale) winter surveys of sea ducks have been conducted on the Atlantic coast or in the Great Lakes that allow analysis of trends for wintering populations. On the Pacific coast, winter survey data from Puget Sound, Washington indicates a steady decline in the combined-scoter index since the mid-1990s, including a 36% decline in white-winged scoters between the survey periods 1999-2001 and 2008-2010.
    Christmas Bird Count data for scoters are probably unreliable because these species occur largely offshore where a large proportion may not be seen by shore-based observers, so those data should be viewed with caution.
    Because the North American population of white-winged scoter is widespread and abundant, and does not meet the criteria for Critically Endangered, Endangered, Vulnerable, or Near Threatened, we recommend this species be listed as Least Concern.

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