speciesaccounts_bewicksswanBewick’s Swan

Cygnus columbianus bewickii

The Northwest European population of Bewick’s Swan winters mainly in Britain, the Netherlands and Germany, with smaller numbers in Denmark, Sweden, Belgium and France. The population breeds at high latitudes in Arctic Russia from the Fenno-Russian border east to the Lena Delta.

There are also two other populations of Bewick’s Swan: an eastern population which breeds in Arctic Russia to the east of the Lena Delta and winters in Japan, China and Korea; and a much smaller population that winters in the Caspian Sea region.

The Northwest European population is a conservation priority, having declined by more than a quarter since the mid 1990s. An AEWA Single Species Action Action Plan was published in 2012 to focus and coordinate conservation efforts.

  • Conservation Status

    Global status (IUCN Red List of Threatened Species) Least Concern*
    African-Eurasian Waterbird Agreement (AEWA) A2; International Single Species Action Plan
    European status (European Red List of Birds) Endangered (Europe and EU27)*
    The Birds Directive (European Commission) Annex I
    UK status (Birds of Conservation Concern) Amber
    UK quarry species (Wildlife & Countryside Act 1981) Schedule 1 (Part 1);  not huntable
    * assessed at species level Tundra Swan Cygnus columbianus

    Population Status

    Flyway population size (CSR 8; Wetlands International 2021) 21,000 individuals
    UK estimate (APEP 4) 4,350 individuals
    GB estimate (Frost et al. 2019) 4,400 individuals
    All-Ireland estimate (Burke et al. 2018) 20 individuals
    UK trend (Frost et al. 2021) 25-year trend (1993/94-2018/19) = 88% decrease
    10-year trend (2008/09-2018/19) = 81% decrease

    Summary statistics

    Table 1. The number of Bewick’s Swans recorded in Britain and Ireland during the International Swan Census, 1984-2020, and the estimate of the size of the Northwest European population (for population level data, see Beekman et al. 2019).

    Census year Number of swans in Britain & Ireland Estimate of NW European population size
    2020 1,290
    2015 4,392 20,149
    2010 7,100* 18,000
    2005 7,216 21,500
    2000 7,597 23,500
    1995 7,563 29,277
    1990 10,758 25,838
    1987 9,166 16,046
    1984 6,239 16,283
    * Previously reported as 7,079. Updated in Beekman et al. 2019

    Table 2. Annual estimates of the percentage of young and mean brood size (young per successful pair) of Bewick’s Swan in Britain (recorded at WWT Welney, Ouse Washes, Nene Washes, WWT Martin Mere, Ribble Estuary and WWT Slimbridge, where age assessments are made annually), 2003/04-2020/21.

    Season Percentage of young (%) Mean brood size
    2020/21 8.9 1.95
    2019/20 8.6 2.1
    2018/19 11.5 1.7
    2017/18 5.2 1.5
    2016/17 16.5 2.0
    2015/16 13.5 1.7
    2014/15 9.7 1.5
    2013/14 14.7 2.1
    2012/13 16.9 1.7
    2011/12 11.5 1.8
    2010/11 10.8 1.7
    2009/10 9.1 1.5
    2008/09 6.4 1.5
    2007/08 4.7 1.4
    2006/07 10.3 1.9
    2005/06 10.9 2.2
    2004/05 9.2 2.0
    2003/04 15.1 2.1
    References

    Beekman, J., K. Koffijberg, J. Wahl, C. Kowallik, C. Hall, K. Devos, P. Clausen, M. Hornman, B. Laubek, L. Luigujõe, M. Wieloch, H. Boland, S. Švažas, L. Nilsson, A. Stipniece, V. Keller, C. Gaudard, P. Shimmings, B-H. Larsen, D. Portolou, A. Degan, T. Langendoen, K.A. Wood & E.C. Rees. 2019. Long-term population trends and shifts in distribution of Bewick’s Swans Cygnus columbianus bewickii wintering in northwest Europe. Wildfowl Special Issue No. 5: 73-102.

    Burke, B., L.J. Lewis, N. Fitzgerald, T. Frost, G.E. Austin & T.D. Tierney. 2018. Estimates of waterbird numbers wintering in Ireland, 20011/12-2015/16. Irish Birds 11: 1-12.

    Frost, T., G.E. Austin, R.D. Hearn, S. McAvoy, A. Robinson, D.A. Stroud, I. Woodward & S.R. Wotton. 2019. Population estimates of wintering waterbirds in Great Britain. British Birds 112: 130-145.

    Frost, T.M., N.A. Calbrade, G.A. Birtles, C. Hall, A.E. Robinson, S.R. Wotton, D.E. Balmer & G.E. Austin. 2021. Waterbirds in the UK 2019/20: The Wetland Bird Survey. BTO, RSPB and JNCC, in association with WWT. British Trust for Ornithology, Thetford.

    Wetlands International. 2021. Waterbird population estimates. Retrieved from http://wpe.wetlands.org/.September 2021.

    Data access

    Bewick’s Swan data for Britain and Ireland presented in Table 1 (Numbers of swans in Britain and Ireland) and Table 2 (Percentage of young/Mean brood size) are licensed under the Open Government Licence 3.0 except where otherwise stated.

    When you use information from this report under the Open Government Licence you must include the following attribution:

    Contains Goose & Swan Monitoring Programme (GSMP) data from “WWT. 2021. Goose & Swan Monitoring Programme: survey results for Bewick’s Swan Cygnus columbianus bewickii. WWT/JNCC/NatureScot, Slimbridge” retrieved from https://monitoring.wwt.org.uk/our-work/goose-swan-monitoring-programme/species-accounts/bewicks-swan/ © copyright and database right 2021. The GSMP is organised by the Wildfowl & Wetlands Trust (WWT) in partnership with the Joint Nature Conservation Committee (JNCC) and NatureScot with fieldwork conducted by volunteers.

  • Northwest European Bewick’s Swans breed at high latitudes in Arctic Russia from the Fenno-Russian border east to the Lena Delta. Birds migrate through the Baltic States to winter primarily in the Netherlands and Britain, with smaller numbers regularly occurring in Germany, Denmark, Belgium and France (Beekman et al. 1985, Rees et al. 1997). Ireland used to also support wintering Bewick’s Swans, but they occur infrequently nowadays as a results of a eastwards shift in winter distribution.

    flyway map bewicks revised_2014

    Flyway of the Northwest European Bewick’s Swan

    The winter distribution of Bewick’s Swan in Britain is highly localised. It has a southerly distribution with the largest flocks in eastern England, especially at the Nene and Ouse Washes. Smaller flocks occur in western England, and relatively small numbers in Wales.

    In Britain, Bewick’s Swans winter on shallow freshwater lakes, marshes or slow-moving rivers, near or adjacent to extensive grasslands liable to flooding. Since the early 1970s, they have taken to foraging on agricultural land, especially on waste root crops, grain stubbles and winter cereals. This switch in diet may be attributed to changes in natural habitat quality imposed by land drainage and land claim and to more extensive planting of arable crops influencing feeding site selection by the birds. Generally, Bewick’s Swans in Britain and Ireland switch from arable foods to natural grasses through the winter. Proportionately, however, arable foods remain the most important over the whole winter period. The increased use of agricultural areas in southeast England may result in some conflict with agricultural interests, particularly on re-seeded grasslands and winter cereals.

    Although this population is protected throughout its range, illegal shooting remains a threat, with 23% of live Bewick’s Swans x-rayed since 2000 found with shotgun pellets embedded in their body tissue (Newth et al. 2011). Shooting has also accounted for the death of 17.3% of dead Bewick’s Swans recovered along their migration route since the 1970s (Newth et al. 2011), and such activity is known to have occurred in the UK (Evans et al. 1973, Brown et al. 1992, Rees & Bowler 2002, Newth et al. 2011). This indicates that illegal shooting remains an issue for Bewick’s Swans, and needs to be addressed at both national and international levels.

    References

    Beekman, J.H., S. Dirksen & T.H. Slagboom. 1985. Population size and breeding success of Bewick’s Swans wintering in Europe in 1983-4. Wildfowl 36: 5-12.

    Brown, M.J., E. Linton & E.C. Rees. 1992. Causes of mortality among wild swans in Britain. Wildfowl 43: 70-79.

    Evans, M.E., N.A. Wood & J. Kear. 1973. Lead shot in Bewick’s Swans. Wildfowl 24: 56-60.

    Newth, J.L., M.J. Brown & E.C. Rees. 2011. Incidence of embedded shotgun pellets in Bewick’s swans Cygnus columbianus bewickii and whooper swans Cygnus cygnus wintering in the UK. Biological Conservation 144: 1630-1637.

    Rees, E.C. & J.M. Bowler. 2002. Tundra Swan (Bewick’s Swan) Cygnus columbianus. In: Wernham, C.V., M.P. Toms, J.H. Marchant, J.A. Clark, G.M. Siriwardena & S.R. Baillie (eds.) The Migration Atlas: Movements of the Birds of Britain and Ireland. Pp. 149-153. T. & A.D. Poyser, London.

    Rees, E.C., J.M. Bowler & J.H. Beekman. 1997. Cygnus columbianus Bewick’s Swan and Whistling Swan. Birds of the Western Palearctic Update 1: 63-74.

  • International Swan Census

    A coordinated, international census of  the Northwest European Bewick’s Swan Population is undertaken every five years, organised by the Swan Specialist Group. Counts in Britain and Ireland are coordinated by WWT (as part of the GSMP) in association with BirdWatch Ireland (I-WeBS) and the Irish Whooper Swan Study Group. The census covers many non-wetland and/or temporarily flooded areas that are not routinely covered by other annual schemes.

    Results from the censuses are presented in various reports and papers. See our Reports & newsletter page.

    A summary of the results from the latest census is presented on the ‘Latest results’ tab.

    Find out more about the International Swan Census

    Wetland Bird Survey and Irish Wetland Bird Survey

    Bewick’s Swan numbers in the UK and Republic of Ireland are monitored annually through the Wetland Bird Survey (WeBS) and the Irish Wetland Bird Survey (I-WeBS), respectively. Although these schemes provide coverage of a high proportion of wintering sites used by Bewick’s Swans, a number of non-wetland or temporally flooded areas are not surveyed, hence a more comprehensive census, that focuses specifically on Bewick’s Swans, is required to estimate total numbers in Britain and Ireland; such a survey is undertaken every five years (see above).

    GSMP age assessments

    The annual breeding success of the Northwest European population of Bewick’s Swan is monitored in Britain through age assessments that are undertaken annually throughout the autumn and early winter. Counters record the number of first-winter birds present within a flock and individual brood sizes (i.e. how many young in each family group).

    Results from these age assessments are presented on the ‘Latest results’ tab, and a summary of annual estimates can also be found on the ‘Status summary’ tab.

    Find out more about age assessments

  • Results from 2020/21 [added September 2021]

    Abundance

    WeBS/I-WeBS

    The abundance of Bewick’s Swans in the UK and the Republic of Ireland in 2019/20 was monitored through the Wetland Bird Survey (WeBS) and the Irish Wetland Bird Survey (I-WeBS), respectively. Results from these schemes are presented in survey reports which are available to download from the schemes’ websites.

    International Swan Census

    The international census of the Northwest European Bewick’s Swan population is carried out every five years. The census is organised overall by the IUCN SSC Swan Specialist Group, and coordinated in Britain and Ireland by WWT in partnership with Birdwatch Ireland and the Irish Whooper Swan Study Group.

    The 9th census was undertaken in January 2020. The census yielded a total of 1,290 Bewick’s Swans in Britain and Ireland, which represents a decline of 70.5% compared with the total recorded in January 2015 (4,392 birds), and is by far the lowest census total to date (Figure 1).

    Figure 1. Number of Bewick’s Swans recorded in Britain and Ireland during the International Swan Census (columns) and the Northwest European population estimate (line; Beekman et al. 2019), 1984–2020.

    A total of 1,278 Bewick’s Swans was recorded in Britain. Swans were recorded at 22 sites in England, from Lancashire to Hampshire (Figure 2). No birds were recorded in Wales or Scotland. The majority of birds (79.8% of the British total) were recorded at two sites: The Ouse Washes, Norfolk/Cambridgeshire (873 birds), and the Nene Washes, Cambridgeshire (147). WWT Slimbridge (Severn Estuary) recorded 89 birds and all other sites held fewer than 50 birds.

    A total of 12 Bewicks’ Swans were recorded in Ireland. Swans were recorded at two sites there (Figure 2), with one site, Wexford Harbour & Slobs (Wexford) holding 11 birds, whilst the other site, Brideswell (Roscommon) held just one bird. No Bewick’s Swans were recorded in Northern Ireland during the census.

    During the census, only the Ouse Washes held numbers exceeding the 1% threshold for international importance (220 individuals, Wetland International 2021), whilst WWT Slimbridge (89 birds) and Ludham Airfield, Norfolk (45 birds), each supported numbers above the national 1% threshold for Britain (44 birds, Woodward et al. 2020). No sites in Ireland supported numbers above the All-Ireland 1% threshold for national importance (20 birds, Burke et al. 2018).

    Figure 2. Number and distribution of Bewick’s Swans recorded in Britain and Ireland during the International Swan Census, January 2020.

    Breeding success

    Bewick’s Swans age assessments were conducted in three regions across England during mid-winter 2020/21 (19–22 January 2021). A relatively high proportion of early arrivals in Britain (i.e. those present in October and November) typically comprise mostly non/failed breeders (Rees et al. 1997), whereas age assessments made in mid-winter can be taken as being more representative of the population as a whole.

    A total of 547 Bewick’s Swans was aged: 462 in East Central England, six in Northwest England and 79 in Southwest England (Table 1). Brood sizes were recorded for 21 families. The number of birds aged in East Central England (the key region for the species in Britain) was lower than in previous years due to fewer birds wintering there during 2020/21: a peak of 657 Bewick’s Swan was recorded at the Ouse/Nene Washes in January 2021 (WWT unpublished data) compared with 1,020 in January 2020.

    Overall, Bewick’s Swan flocks contained 8.8% cygnets, which is notably lower than the previous ten-year average recorded at wintering sites in England (12.1%  1.14 SE 2010/11–2019/2020). The mean brood size of 1.95 young per successful pair was slightly higher than the previous ten-year mean (1.69 ± 0.05 SE, 2010/11–2019/20).

    Table 1. The percentage of young (%) in flocks and mean brood size for Bewick’s Swans at sites in England during the 2020/21 winter (regions defined below).

    Region Total aged Percentage of young (%) Number of broods Mean brood size
    Northwest England 6 (0) Limited data 0 Limited data
    East Central England 462 (45) 9.7 19 (38) 2.00
    Southwest England 79 (3) 3.8 2 (3) 1.50
    Overall  547(48) 8.8 21 (41) 1.95

    *Regions (counties from which data were received in 2020/21):

    • Northwest England: Lancashire (Thurnham Moss)
    • East Central England: Cambridgeshire (WWT Welney, Ouse Washes, Nene Washes), Norfolk (Ouse Washes).
    • Southwest England: Gloucestershire (WWT Slimbridge).

    Age assessments of Bewick’s Swans have been regularly undertaken at and around WWT Centres (WWT Welney/Ouse and Nene Washes, WWT Slimbridge and WWT Martin Mere/Ribble Estuary) since the early 1960s. In 2020/21, the mean percentage of young in flocks assessed for these sites combined was 8.9% (541 birds aged) (Figure 3), which was lower than the previous ten-year mean (11.9 young  1.14 SE). The combined mean brood size of 1.95 cygnets per successful pair for the 21 broods assessed was slightly higher than the previous ten-year mean (1.78  0.07 SE). In recent years, few or no birds have been recorded at the Ribble Estuary and WWT Martin Mere, particularly at the latter site. For years when only a small sample size (<15 birds aged) was assessed at these sites, the data have been excluded from this analysis (i.e. for 2011/12, 2015/16 to 2020/21).

    Figure 3. The percentage young (blue circles), with the rolling five-year mean (red line), and mean brood size (green triangles) for Bewick’s Swans recorded at WWT centres combined (WWT Slimbridge, WWT Welney/Ouse and Nene Washes, and WWT Martin Mere/Ribble Estuary), 2006/07–2020/21. Five year mean values for the percentage of young was calculated for the five years preceding the year in question (e.g. mean presented for 2020/21 is for the 2015/16–2019/20).

    Discussion

    These data indicate that Bewick’s Swans continued to experience relatively poor breeding success in 2020 with flocks containing 8.8% young which is notably lower than the previous ten-year average (11.9%) recorded at wintering sites in England.

    Conditions on the breeding grounds are likely to be important in determining the population’s breeding success, in particular, weather conditions during the short Arctic breeding season (Poorter 1991). However, temperatures in the Pechora Delta (in the vicinity of an important breeding area for the species) in May 2019 averaged 4.6˚C which was higher than the previous five-year average for the area (2.5˚C) (TuTiempo 2021). Therefore, other factors such as predator (e.g. Arctic fox) abundance may have been influential (Wood et al. 2016) and reports from monitoring stations in the breeding grounds in Arctic Russia (Soloviev & Tomkovich 2020) suggests that Arctic fox abundance at some sites were abundant, therefore potentially predating young Bewick’s Swan cygnets. Inter-annual variability in breeding success is sensitive to the combined effects of both intrinsic factors (such as pair bond duration, with more experienced pairs raising more young) and extrinsic factors (such as low temperatures on the breeding grounds and predator pressure) having a negative impact on breeding success (Wood et al. 2016).

    At the time of writing, no data were available on the breeding success of Bewick’s Swans wintering elsewhere along the flyway, so it is uncertain how representative the estimates from Britain are of the population as a whole.

    Results from the January 2020 Bewick’s Swan census suggest that the number of birds wintering in Britain (1,278 birds) has fallen considerably since the previous census in 2015 (4,371). They also highlight a pronounced decline since a period when numbers recorded during the censuses (in 1995 to 2010) remained relatively constant. Furthermore, with just two sites in Ireland reporting 12 birds in total in 2020 (compared with 21 in 2015), it is clear that the Bewick’s Swan is becoming an increasingly scarce bird in Ireland, with numbers having decreased rapidly since the peak of 2,004 birds recorded there during the census in 1990.

    The low numbers of Bewick’s Swans found in Britain and Ireland during the census is likely due to the combined influence of an overall population decline and the so-called short-stopping phenomenon that many wintering waterbirds are now exhibiting, whereby they winter further east within Europe than they once used to (Nuijten et al. 2020).

    At the time of writing, results of the 2020 census from other countries across the flyway are still being collated; given the low numbers recorded in Britain and Ireland, it will be interesting to see how the results compare with those from elsewhere in Europe.

    Overall results from the 2020 International Bewick’s Swan Census will be reported by the SSC.

    Acknowledgements

    As always, our thanks go to the network of dedicated GSMP volunteers for their help with collecting age assessments. Our thanks also go to the many counters who took part in the International Swan Census in Britain and Ireland, including WeBS and I-WeBS counters, and to Birdwatch Ireland and Graham McElwaine Irish Whooper Swan Study Group for coordinating counts across Ireland.

    References

    Beekman, J., K. Koffijberg, J. Wahl, C. Kowallik, C. Hall, K. Devos, P. Clausen, M. Hornman, B. Laubek, L. Luigujõe, M. Wieloch, H. Boland, S. Švažas, L. Nilsson, A. Stipniece, V. Keller, C. Gaudard, A. Degen, P. Shimmings, B-H. Larsen, D. Portolou, T. Langendoen, K.A. Wood & E.C. Rees. 2019. Long-term population trends and shifts in distribution of Bewick’s Swan Cygnus columbianus bewickii wintering in northwest Europe. Wildfowl Special Issue 5: 73–102.

    Burke, B., L.J. Lewis, N. Fitzgerald, T. Frost, G.E. Austin & T.D. Tierney. 2018. Estimates of waterbird numbers wintering in Ireland, 20011/12–2015/16. Irish Birds 11: 1–12.

    Nuijten, RJM., Wood, KA, Haitjema, T, Rees, EC & Nolet, BA. Concurrent shifts in wintering distribution and phenology in migratory swans: Individual and generational effects. Global Change Biology. 2020; 26: 4263– 4275. https://doi.org/10.1111/gcb.15151

    Poorter, E.P.R. 1991. Bewick’s Swans Cygnus columbianus bewickii, an analysis of breeding success and changing resources. Ministerie van Verkeer en Waterstaat, Rijkswaterstaat, Directie Flevoland.

    Rees, E.C., J.S. Kirby & A. Gilburn. 1997. Site selection by swans wintering in Britain; the importance of habitat and geographic location. Ibis 139: 337–352.

    Soloviev, M. & P.S. Tomkovich. 2020. Arctic Birds: an international breeding conditions survey. Online database: http://www.arcticbirds.net/. Accessed 08/06/2021.

    TuTiempo. 2021. http://www.tutiempo.net/en/.Accessed June 2021.

    Wetlands International. 2021. Waterbird population estimates. http://wpe.wetlands.org/. Accessed July 2021.

    Wood, K. A., J.L. Newth, G.M. Hilton, B.A. Nolet & E.C. Rees. 2016. Inter-annual variability and long-term trends in breeding success in a declining population of migratory swans. Journal of Avian Biology. DOI: 10.1111/jav.00819.

    Woodward, I., N. Aebischer, D. Burnell, M. Eaton, T. Frost, C. Hall, D. Stroud & D. Noble. 2020. Population estimates of birds in Great Britain and the United Kingdom. British Birds 113: 60–104.

    Data access

    Bewick’s Swan abundance data for Britain and Ireland presented in this report are licensed under the Open Government Licence 3.0 except where otherwise stated.

    Bewick’s Swan breeding success data for England presented in this report, with the exception of data for 2018/19 and 2019/20 presented in Figure 3 (percentage of young/mean brood size for Bewick’s Swans recorded around WWT centres), are licensed under the Open Government Licence 3.0 except where otherwise stated.

    When you use information from this report under the Open Government Licence you must include the following attribution:

    Contains Goose & Swan Monitoring Programme (GSMP) data from “WWT. 2020. Goose & Swan Monitoring Programme: 2019/20 survey results for Bewick’s Swan Cygnus columbianus  bewickii. WWT/JNCC/NatureScot, Slimbridge” retrieved from https://monitoring.wwt.org.uk/our-work/goose-swan-monitoring-programme/species-accounts/bewicks-swan/ © copyright and database right 2020. The GSMP is organised by the Wildfowl & Wetlands Trust (WWT) in partnership with the Joint Nature Conservation Committee (JNCC) and NatureScot with fieldwork conducted by volunteers.

  • Previous annual results will be archived here. Published results from the International Swan Census can be found on the Reports & newsletter page.

    2019/20 Results

    2018/19 Results

    2017/18 Results

    2016/17 Results

    2015/16 Results 

    2014/15 Results

    2013/14 Results

    2012/13 Results

    2011/12 Results

    2010/11 Results

    2009/10 Results

    2008/09 Results

    2007/08 Results

    2006/07 Results

    2005/06 Results

     

     

  • Background

    Bewick’s Swans have been marked, initially just with metal rings, at WWT Slimbridge since 1961 and until the late 1960s this was the only location in Britain where the species was ringed in any number. During this time the study focused on individual recognition of birds by their unique bill pattern (see WWT’s website for more details).

    Then in 1967, a regular colour-marking programme was introduced that enabled information to be gathered about the birds whilst on migration, at staging sites and at other wintering sites (Mitchell & Ogilvie 1997, Rees & Bowler 1996). Individual birds could then be monitored throughout their lifetime to determine factors affecting their pairing and breeding successes, survival rates and site selection. This information could be used to explain changes in the swans population size and distribution and enabled researchers to identify their ecological needs (Rees 2006). Such detailed information was and still is invaluable in supporting conservation efforts for Bewick’s Swan, a species that has declined by 27% between 1995 and 2005.

    At WWT centres, swans are caught in a specially designed ‘swan pipe’ – a long, netted trap which is baited with food to encourage birds to enter, where they can be caught by dropping a gate to close off the entrance. The first swan pipe was built at WWT Slimbridge in 1969 and, following its success, more were built at WWT Welney in 1980 and at WWT Martin Mere in 1990, extending the colour-marking programme to other parts of Britain (Owen et al. 1986, Rees & Bowler 1996).

    Ringers in the Netherlands started regularly marking Bewick’s Swans in 1985 and more recently birds have been caught and ringed at migratory sites in Germany, Denmark and Estonia and on the breeding grounds in arctic Russia (Rees & Bowler 2002). From 1991 to 2008, WWT joined expeditions with the All-Russian Research Institute for Nature Protection to arctic Russia to study the swans on their breeding grounds.

    Resightings of colour-marked Bewick’s Swans have lead to a number of important discoveries, including:

        • confirmation of the migratory route from the breeding grounds to the wintering grounds: the swans migrate from the breeding grounds along the arctic coast of Russia to the White Sea, head southwest across Karelia to the Gulf of Finland and the Baltic coast, following the northern and southern shores of the Baltic to the wintering grounds in northwest Europe (Rees & Bowler 2002).
        • confirmation that Estonia, the White Sea region and the Pechora Delta are vital staging and breeding areas (Rees & Bowler 2002).
        • evidence that swans wintering in different parts of Britain may have different migratory routes. Swans ringed in northwest England and southwest Scotland (at WWT Martin Mere and WWT Caerlaverock, respectively) have a more northerly distribution than those ringed in southern Britain (at WWT Welney and WWT Slimbridge). Further investigation has shown those birds marked in northwest England are more likely to be reported in Denmark, Germany and Northern Ireland, whilst those ringed in the southwest are more likely to be seen in the Netherlands and other parts of Britain (Rees & Bowler 2002).

    WWT colour-ringing

    Bewick’s Swans are caught and ringed every winter at WWT Slimbridge and WWT Welney. This is undertaken as part of our long-term life-history study on the species. Each bird is fitted with a coloured leg ring, as well as a metal ring, and various body size measurements and samples are taken to assess its condition and health. By catching these birds we have been able to identify issues affecting them, such as illegal shooting and lead poisoning (Newth et al. 2011, Newth et al. 2012). This information helps to inform subsequent conservation measures taken to reduce the scale of these threats.

    Ring combinations used
    White leg rings (black lettering) Yellow leg rings (black lettering) Green leg rings (white lettering)
    Alpha/alpha/alpha APA – TXZ EXJ – ZCZ AAA – AES
    Numeric/numeric/alpha 11A-24S
    Numeric/numeric/numeric 396-910

    If you see any colour-marked Bewick’s Swans with these combinations please send your sightings to colourmarkedwildfowl@wwt.org.uk

    Project partners

    We work with the All-Russian Research Institute for Nature Protection, the Danish Ministry of the Environment, Komi Science Centre, the Museum and Institute of Zoology at the Polish Academy of Sciences, and the University of Groningen.

    References

    Mitchell, C. & M. Ogilvie. 1997. Fifty years of wildfowl ringing by the Wildfowl & Wetlands Trust. Wildfowl 47: 240-247.

    Owen, M., G.L. Atkinson-Willes & D.G. Salmon. 1986. Wildfowl in Great Britain; Second Edition. Cambridge University Press, Cambridge.

    Rees, E.C. 2006. Bewick’s Swan. T. & A.D. Poyser, London.

    Rees, E.C. & J.M. Bowler. 2002. Tundra Swan (Bewick’s Swan) Cygnus columbianus. In: Wernham, C.V., M.P. Toms, J.H. Marchant, J.A. Clark, G.M. Siriwardena & S.R. Baillie (eds.) The Migration Atlas: Movements of the Birds of Britain and Ireland. Pp. 149-153. T. & A.D. Poyser, London.

    Rees, E.C. & J.M. Bowler. 1996. Fifty years of swan research and conservation by the Wildfowl & Wetlands Trust. Wildfowl 47: 248-263.

     

  • Relevant publications

    AEWA International Single Species Action Plan

    Beekman, J., K. Koffijberg, J. Wahl, C. Kowallik, C. Hall, K. Devos, P. Clausen, M. Hornman, B. Laubek, L. Luigujõe, M. Wieloch, H. Boland, S. Švažas, L. Nilsson, A. Stipniece, V. Keller, C. Gaudard, A. Degen, P. Shimmings, B-H. Larsen, D. Portolou, T. Langendoen, K.A. Wood & E.C. Rees. 2019. Long-term population trends and shifts in distribution of Bewick’s Swan Cygnus columbianus bewickii wintering in northwest Europe. Wildfowl Special Issue 5: 73-102. Download

    Kear, J. 2005. Ducks, geese & swans. Oxford University Press.

    Newth, J.L., M.J. Brown & E.C. Rees. 2011. Incidence of embedded shotgun pellets in Bewick’s swans Cygnus columbianus bewickii and whooper swans Cygnus cygnus wintering in the UK. Biological Conservation 144: 1630-1637.

    Rees, E.C. 2006. Bewick’s Swan. T. & A.D. Poyser, London.

    Rees, E.C. & J.H. Beekman. 2010. Northwest European Bewick’s Swan: a population in decline. British Birds 103: 640-650.

    Rees, E.C. & S.B. Rozenfeld. 2020.  Cygnus columbianus Tundra Swan. In V. Keller, S. Herrando, P. Voříšek, M. Franch, M. Kipson, P. Milanelsi, D. Martí, M. Anton, A. Klvaňová, M.V. Kalyakin, H.G. Bauer & R.P.B. Foppen (eds.), European Breeding Bird Atlas 2: Distribution, Abundance and Change, pp. 105. European Bird Census Council & Lynx Edicions, Barcelona, Spain.

    Robinson, J.A., K. Colhoun, J.G. McElwaine & E.C. Rees. 2004. Bewick’s Swan Cygnus columbianus bewickii (Northwest Europe population) in Britain and Ireland 1960/61 – 1999/2000. Waterbird Review Series, The Wildfowl & Wetlands Trust/Joint Nature Conservation Committee, Slimbridge. Download

    Wood, K.A., J.L. Newth, K. Brides, M. Burdekin, A.L. Harrison, S. Heaven, C. Kitchin, L. Marshall, C. Mitchell, J. Ponting, D.K.Scott, J. Smith, W. Tijsen, G.M. Hilton & E.C. Rees. 2018.  Are long-term trends in Bewick’s Swan Cygnus columbianus bewickii numbers driven by changes in winter food resources. Bird Conservation International: 1-18Download

    Other relevant material

    Wetland Survey Report online

    BirdLife International Species factsheet

    British Trust for Ornithology: Bird Facts