Archived 2015 topics: Common Pochard (Aythya ferina) – uplist from Least Concern to Near Threatened or Vulnerable?

Common Pochard Aythya ferina breeds from W Europe eastwards through C Asia (in band at 40–60° N) to SC Siberia and N China to 120° E, and winters south to N & E Africa, India and S & E Asia (Carboneras & Kirwan 2014). It is currently listed as Least Concern, because when last assessed it was not thought to approach the thresholds for Vulnerable under any of the IUCN Red List criteria.

Globally, it has an extremely large range in both the breeding season (>16 million km2) and in winter (>11 million km2), and hence does not approach the thresholds for Vulnerable under the range size criteria (B and D2). Its population size is also extremely large (1,950,000–2,250,000 individuals; Wetlands International 2012), 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. Until recently, the population was thought to be declining slowly, but not 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).

New data collated from across Europe for the European Red List of Birds (BirdLife International 2015) indicate that the species has declined significantly in recent years, and that this decline is ongoing. A combination of official data reported by 27 EU Member States to the European Commission under Article 12 of the EU Birds Directive and comparable data from other European countries, provided by BirdLife Partners and other leading national ornithologists, suggests that both the European breeding and wintering populations have declined overall by around 40% over the last three generations (22.8 years, based on a generation length estimated by BirdLife to be 7.6 years). This corresponds well with the strong declining trends evident in the two main flyway populations using Europe between 1988–2012, based on midwinter counts conducted as part of the International Waterbird Census (Nagy et al. 2014). Consequently, the species is now classified as Vulnerable at European level (BirdLife International 2015).

Based on the latest estimates (Wetlands International 2012), Europe holds between 35% (breeding) and 40% (wintering) of the global population, so these declines are significant. A third flyway population (breeding in W Siberia and wintering in SW Asia) also appears to be declining, although this may at least partly reflect recent variation in monitoring effort (Nagy et al. 2014). No recent information is available about the sizes or trends of the two other flyway populations, which breed in C Asia and winter in S and E Asia, respectively (Wetlands International 2012), and which together are thought to comprise around one third of the global population. Depending on whether these Asian flyway populations are declining, and at what rate, then overall the species may qualify for uplisting to globally Near Threatened or Vulnerable under criterion A.

Comments on this proposal are welcome, along with any data on the current sizes and trends of the Asian flyway populations, and any information about the threats affecting this species across its range.

References

BirdLife International (2015) European Red List of Birds. Luxembourg: Office for Official Publications of the European Communities. http://www.birdlife.org/datazone/info/euroredlist
Carboneras, C. & Kirwan, G.M. (2014). Common Pochard (Aythya ferina). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.) (2014). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. www.hbw.com
Nagy, S., Flink, S., Langendoen, T. (2014) Waterbird trends 1988-2012: Results of trend analyses of data from the International Waterbird Census in the African-Eurasian Flyway. Wetlands International, Ede. http://www.wetlands.org/Portals/0/TRIM%20Report%202014_10_05.pdf
Wetlands International (2012) Waterbird Population Estimates: 5th edition. wpe.wetlands.org

 

Additional data received 9 July 2015

Wetlands International have provided wintering trend data for 1991-2014 from across the global range, taken from the International Waterbird Census Database – please see Word file downloadable from the below link:

Aythya ferina IWC data

 

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20 Responses to Archived 2015 topics: Common Pochard (Aythya ferina) – uplist from Least Concern to Near Threatened or Vulnerable?

  1. Dr Anwaruddin Choudhury says:

    It is also matter of concern. IN NE India, they mainly winter in Assam and Manipurwith passage migrants in Arunachal Pradesh and a few in Tripura. They are normally seen in smaller groups and their number is also relatively lower than Ferruginous ducks, Pintails, Gadwalls, Wigeons, etc. But if their breeding population showed significant decline, apparently wintering numbers would also decline, which may not be visible immediately but in course of time. Hence, upgrading to NT may ensure better conservation attention.

  2. Andy Symes (BirdLife) says:

    Szabolcs Nagy and Tom Langendoen of Wetlands International have provided wintering trend data for 1991-2014 from across the global range, taken from the International Waterbird Census Database.

    Please see the link in the references in the main forum topic.

  3. Wieland Heim says:

    In Russia´s Amur Oblast at the middle stream of Amur river observations of Common Pochard are increasing. It was only known as a vagrant during the 1980´s but is now recorded annually during migration in increasing (but still small) numbers. In 2015 we recorded the species for the first time during breeding season, when 6 males and 1 female were seen 7th of June on a lake south of Muraviovka Park.
    At Khanka Lake in Russia´s Primorye region the first breeding was recorded in 2004.
    However, I can not say if these changes only reflect increasing observer effort.

    Source: http://redbook-amur.ru/5-29.php

  4. Nicola Baccetti says:

    Wintering numbers of both Common Pochard and Greater Scaup have significantly decreased in the 2001-10 decade across Italy, the latter species now regularly occurring just at a single wetland. See the trends in https://www.researchgate.net/publication/270759692_Risultati_dei_censimenti_degli_uccelli_acquatici_svernanti_in_Italia._Distribuzione_stima_e_trend_delle_popolazioni_nel_2001-2010

  5. Dr. Nicky Petkov says:

    For many of the wintering waterbirds there is impact of the very mild and warm winters in the last decades which make the birds to short stop along the flyways and if the monitoring coverage is poor at those countries as it might be in some parts of Russia and Ukraine there might be lack of data. So numbers should not be assessed by countries but rather by flyway populations.

    This is a species which definitely is increasing in distribution and numbers in Bulgaria as breeder and continue to have quite sizable wintering population as well. While doing my research on it during breeding season in Bulgaria and comparing to other diving duck as the Ferruginous Duck I found that Pochard is much more flexible towards ecological changes in wetlands and occupies far more diverse type of wetlands, while Ferruginous Duck was more bound to the specific micro habitats it likes and requires for breeding and changes in the habitat probably impact it quite quickly.

    • Dr. Szabolcs Nagy says:

      Nicky,

      We have analysed the data both by flyways and by smaller groups of countries. The result is the same. We see no evidence of short-stopping in the better monitored parts of Europe. In the Black Sea-Mediterranean flyway, there is indeed an increase in Russia and a contemporary decline in other Black Sea and East Mediterranean countries but this is rather the results of improved monitoring there and does not compensate for the losses. Besides, both BirdLife’s and the Duck SG’s inquiry show also decline in the main European breeding countries while it is increasing in the marginal ones. See http://www.birdlife.org/datazone/userfiles/file/Species/erlob/supplementarypdfs/22680358_aythya_ferina.pdf

      I am rather confident about the trend in Europe. We would need better understand the situation in Asia where IWC data also suggest declines but it has a less comprehensive coverage than in Europe.

      • Nicky Petkov says:

        Szabolcs,

        correct me if wrong, but the C Europe, Black Sea, Mediterranean (non-bre) flyway population which is the largest could the birds there be short stopping in areas in Southern Russia or Ukraine. I had an email exchange with Tom over figures from IWC for Pochard in Burgas area and the high counts there are not related to increase in monitoring efforts or else. The effort has been one and the same in the past 20 years. The only positive relation in this area which holds quite big numbers up to 45 000 birds is mostly related to weather conditions, though have not looked into details of its wintering numbers. When winter is mild we have less of those and when up North there is heavy snowfall and cold spell ducks come in numbers. I would say there is decline in monitoring efforts in key areas like Azov – Sivash (we discussed with you the issues there) in recent years, not sure how good is the coverage in southern Russia though… The species has quite large breeding range and with deficiency in the data from Asia it will be very Europecentered status decision. It is quite plastic in occupying variable types of wetlands for breedings, it has expanded its range in Europe after mid of 1900s and as it seems from one of the messages it is continuing to expand range in some parts. It has definitely increased as breeder in Bulgaria, while winter numbers fluctuate much depending on what type of winter we have each year…. simply saying I have my doubts on the possible lack of data from key areas to make a well informed decision. A NT might be good option as precautionary approach and to try and get better data from other regions.

  6. Andy Symes (BirdLife) says:

    Milan Vogrin provided the following comment:
    In Slovenia for example during last decade it become more common nester then before. However this is not in the main area of this species. During winter, numbers fluctuate but look like that they decline

  7. Michele Sorrenti says:

    Collection of harvest data in Italy shows decline in one northern region and stable-fluctuating trends in other 3 regions. Series from 2003-04 to 2012-2013. Harvest take place mainly in autumn, so this data could reflect numbers of migrant population rather than wintering one. If coverage is good also in Northern Africa then the decline in West Mediterranean is real, as it is in Europe. I think that there are sufficient data for down listing species to NT, as numbers and distribution make the Vulnerable definition a bit excessive in such moment.

  8. Andy Symes (BirdLife) says:

    Raimo Virkkala of the Finnish Environment Institute has provided the following comment:
    “..the uplisting of many other species of which I have knowledge or census data is well-founded and acknowledged here. These include e.g. Common Pochard Aythya ferina, Meadow Pipit Anthus pratensis, Redwing Turdus iliacus and Rustic Bunting Emberiza rustica.”

  9. In Lithuania registered continiously decresing (with 10-30% short-term rate) of the breeding population, mainly because of eutrophication of the lakes, which determine the changes of water plants communities and disapearing of the Chara sp. algae species/communities, which are important for feeding of the species during breeding season. This fact confirms the rapid decline of the breeding population in the regions with intensive agriculture in Lithuania. While in some waterbodies, which are not surrounded with intensive agriculture fields, the population is quite stable.

  10. R.K. Birjit Singh says:

    Common Pochard (Aythya ferina) which was once a very common wintering duck in Loktak Ramsar, Manipur is no more a common waterbird in Loktak and in the entire north-east India. It has been confined to a few pockets during winter in Loktak Lake in Manipur.

  11. Virag Vyas says:

    Common Pochard still is a fairly common winter visitor to Gujarat. It arrives in Nalsarovar in numbers atleast 5000+. It may be even more. Also in several wetlands of Gujarat (Western India)its numbers are quite high and I feel Wetlands of Gujarat are a safe haven for the species.

  12. Richard Hearn says:

    Whilst collating information on the status of Common Pochard in Asia during April 2015 I received the following replies. They paint a rather mixed picture regarding trends, but it seems they largely support the analysis of IWC data.

    Diana Solovyeva (Russia): Real datset for Russia is missed, but recent information indicated increase at Khanka Lake and Torey Lakes.

    Sayam Chowdhury (Bangladesh): The recent AWC counts from two major wetland sites from Bangladesh are attached below. It is difficult to clearly understand the trend since the numbers fluctuate and survey effort were possibly not same every year. However, these do reflect a decreasing population in Bangladesh. Please also consult the old AWC counts which are already published.

    Site;2006;2007;2008;2009;2010;2011;2012;2013;2014
    Hakaluki Haor;856;1,163;10,029;1,304;24;1,938;Not surveyed;Not surveyed;338
    Tanguar Haor;See AWC;See AWC;6,526;10,917;4,057;721;1,388;1,625;Not counted

    Katsumi USHIYAMA (Japan): Here’s one paper documenting a declining trend of Common Pochards wintering in Japan: Population Trends of Common Wintering Waterfowl in Japan: Participatory Monitoring Data from 1996 to 2009
    http://www.bioone.org/doi/abs/10.2326/osj.9.23

    Another survey, Monitoring site 1000, started in 2008 which focuses more on the important sites also shows a declining trend of Common Pochards. There also is a trend that the sex ratio is more biased to males in the northern wintering sites and maybe as a whole also.

    Nial Moores (South Korea): Common Pochard is a winter visitor and migrant through the ROK, with very few birds (35,000 in 2009, a >50% decline between 2002 and 2013, and most of this decline since 2010). I have attached a mini-graphic showing the trend recorded by the Ministry of Environment winter census, with separate lines for sites counted every winter of the census and for sites counted only in later years.

    More anecdotally, based on discussions over the years, it appears that we might be receiving Common Pochard from two directions in winter: from “our” west and from “our” north, perhaps with an increasing proportion of our Pochard now coming from Russia.

    Ma Ming (China): In fact, in China the population size of Common Pochard is little change in the number, which belongs to the common species in migration season, or over-wintering species. We did not feel the change, we/you can refer to the website of Chinese Birding Record or China Bird Report from 2004-2014 (http://www.birdreport.cn/user/index/record).

    Sundev Gombobaatar (Mongolia): According to our assessment of the species in 2011, a critical change of the pochard population in Mongolia has not been reported. If you need detail data and info on the species, we would share regional red list for Mongolian bird published in 2011.

  13. Andy Symes (BirdLife) says:

    Preliminary proposals

    Based on available information, our preliminary proposal for the 2015 Red List would be to treat:

    Common Pochard as Near Threatened under criterion A2+3+4.

    There is now a period for further comments until the final deadline of 31 August, after which the recommended categorisation will be put forward to IUCN.

    The final Red List categories will be published on the BirdLife website in late October and on the IUCN website in November, following further checking of information relevant to the assessments by both BirdLife and IUCN.

  14. I think it is a fairly common species in India. As it is a winter migrant in most parts of India. India, gets a huge number of migratory birds of this species. the status here will be “Least Concern”. But if there are issues in it’s breeding range or other wintering areas the issues should be studied.

  15. Alain Caizergues says:

    It is implicitly assumed that census data currently available are reliable, that is: 1) that “noises” (sampling error, numerous sources of bias…) known to be associated with count data don’t preclude assessing temporal trends correctly, 2) that the true size of the population is correctly estimated and, more importantly, 3) that winter counts actually reflect variations in demographic parameters (rather than variations in spatio-temporal distributions of individuals for example).
    I my opinion none of these points have been seriously addressed yet. Are there standardized protocols available for estimating numbers of ducks in the framework of European monitoring schemes? Which ones? Are they applied in all countries? Are we actually estimating population size or do we aim to assess population trends? Is the current scheme suitable for detecting short-stopping? All such questions need formalized answers. In particular, short-stopping need to be tested properly and not just discarded by saying that the increase observed would be due to increases in sampling effort (one may use stable isotope to do that).
    Our experience in France shows that counts poses problem for monitoring breeding populations especially concerning diving ducks. True numbers of breeder was found to be between 2 and 3 times higher than the estimates derived from counts and these estimates are particularly biased when nesting success is low. Moreover, we estimated that sampling schemes concerning both the wintering and breeding seasons include less than 10% of the total surface of potential habitats of ducks meaning that current estimates of pop size are greatly underestimated.
    Demographic parameters such as adult survival or breeding success (nest or young survival) do not indicate any particular problem (e.g., current estimates of adult survival are comparable to those obtained in the past). Furthermore, the breeding range is extending and both the breeding and wintering populations are stables. Increasing numbers of nesting attempts are reported in North Africa too.
    Rising methodological issues, does not mean, of course, that the “biological/demographic” part of the problem should be neglected. To address the question of the status of diving ducks populations in North-west Europe a Ph. D. thesis will be launched in 2016. In the mean time, our team of statistician is elaborating a method for estimating population trends of ducks. The achievability (in the field) and efficiency of this new strategy of sampling should be assessed during spring 2016.

  16. Over one decade monitoring of Common Pochard from Chilika Lake and Pong Dam since 2001 indicate the heavy decline in the Wintering numbers during the last six years of both Common Pochard and Tufted Duck. Comparing with the early 2000s numbers the decline of Common pochard in recent years shows over 80-90%. The numbers fluctuated between 2001 and 2005 was 60-100,000. Last two years the numbers never exceeded 5000. Pong Dam the maximum number recorded between 2005 and 2011 fluctuated between 4000 and 12,000. Last two years its number never exceeded 2000. However the wintering range was extended almost the southern tip of India. I suggest to put this species can be considered to uplist to endangered criterion,

  17. Instead of recomemnding to uplis to Vulnerable I wrongly entered as endangered. My suggestion is to update from Least concern to Vulnerable

  18. Andy Symes (BirdLife) says:

    Recommended categorisation to be put forward to IUCN

    Based on further information received, we have been able to change the preliminary proposal and revise the recommended classification on the 2015 Red List to Vulnerable (criterion A). IWC wintering data show three-generation declines of >30% (the threshold for classification as VU under criterion A2/A3/A4) in all regions except central Europe, and although there is always some possibility of wintering distribution changing/increasing short-stopping, there appears to be enough evidence to suspect overall declines of >30% in three generations, and therefore listing as Vulnerable. We note also that although the species might be expected to benefit from a reduction in eutrophication, this does not appear to have been the case.

    The final categorisation will be published on the BirdLife website in late October and on the IUCN website in November, following further checking of information relevant to the assessment by BirdLife and IUCN.

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