speciesaccounts_lightbelliedbrentgoose2Canadian Light-bellied Brent Goose

Branta bernicla hrota

The East Canadian High Arctic (ECHA) population of Light-bellied Brent Goose breeds in Canada and winters almost entirely in Ireland, with smaller numbers in Britain, the Channel Islands and the north coasts of France and Spain.

It undertakes one of the longest migrations of any Western Palearctic goose population, crossing the Greenland ice-cap, staging at sites in Greenland and Iceland before crossing the North Atlantic to Ireland.

Strangford Lough in Northern Ireland hosts over 75% of the population during the late autumn and is now by far the most important site for this species outside the breeding season.

  • Conservation Status

    Global status (IUCN Red List of Threatened Species)

    African-Eurasian Waterbird Agreement (AEWA)

    European status (European Red List of Birds)

    The Birds Directive (European Commission)

    UK status (Birds of Conservation Concern)

    UK quarry species (Wildlife & Countryside Act 1981)

    * assessed at species level Branta bernicla

    Least Concern*

    A3a; International Single Species Action Plan

    Least Concern (Europe and EU27)*

    Annex II (Part B)

    Amber

    not huntable

    Population Status

    Flyway population size (CSR 6; Wetlands International 2015)

    GB estimate (Musgrove et al. 2011)

    Irish estimate (Crowe & Holt. 2013)

    GB trend (SUKB 2016)

    Breeding success (GSMP survey)

    40,500 individuals

    710  individuals

    36,380 individuals

    Long-term trend (1988/89 – 2013/14): 60% increase
    Ten-year trend (2003/04 – 2013/14): 37% increase

    Marked cyclic fluctuation, varying between <1% and 30%

    Summary statistics

    Annual estimates of the population size, percentage of young (%) and mean brood size (young per successful pair) of East Canadian High Arctic Light-bellied Brent Goose, 2003/04-2014/15; recorded during the All-Ireland Light-bellied Brent Goose Census.

    Autumn Estimate of population size Percentage of young (%) Mean brood size
    2015 37,192 12.0 2.16
    2014 31,985 4.1 2.10
    2013 34,734 0.04 0.83
    2012 41,465 1.9 2.61
    2011 48,002 25.0 2.69
    2010 38,708 3.1 3.36
    2009 39,399 0.7 2.00
    2008 37,996 18.2 3.42
    2007 38,993 25.1 3.28
    2006 31,882 2.2 2.33
    2005 32,088 13.2 3.22
    2004 32,923 21.7 3.43
    2003 28,714 17.9 2.30

     

    References

    Crowe, O. & C. Holt. 2013. Estimates of waterbird numbers wintering in Ireland, 2006/07-2010/11. Irish Birds 9: 545-552

    Musgrove, A.J., G.E. Austin, R.D. Hearn, C.A. Holt, D.A. Stroud & S.R. Wotton. 2011. Overwinter population estimates of British waterbirds. British Birds 104: 364-397.

  • The East Canadian High Arctic population of Light-bellied Brent Goose breeds in the eastern Queen Elizabeth Islands from eastern Melville Island to Devon Island and northern Ellesmere Island. Almost all of these geese winter in Ireland, with much smaller numbers reaching the west coast of Britain, the Channel Islands, and the north coasts of France and Spain. It undertakes one of the longest migrations of any Western Palearctic goose population, crossing the Greenland ice-cap, staging at sites in Greenland and Iceland before crossing the North Atlantic to Ireland.

    flyway map brent_ECHALB

    Flyway of the East Canadian High Arctic Light-bellied Brent Goose

    Strangford Lough in Northern Ireland hosts over 75% of the population during the late autumn and is now by far the most important site. Lough Foyle, on the north coast, has also become increasingly important in recent years as a landfall site. As winter progresses, these geese disperse around the coast of Ireland, favouring sites in the northwest, east, southeast, southwest and west of the country with notably high numbers at Dublin Bay and Wexford Harbour and Slobs. Over 3,000 also disperse thinly along the rocky coastlines of Ireland in the late winter (Robinson et al. 2004).

    It has been suggested that Light-bellied Brent Geese may have relied almost entirely on Zostera during the winter, before a wasting disease caused almost the entire depletion of Zostera in Ireland during the 1930s. Since then, the diet in estuarine and saltmarsh areas has become more cosmopolitan, including algal foods such as Enteromorpha and Ulva, and saltmarsh plants such as Festuca and Puccinella. Inland feeding was first recorded in Ireland and Iceland during the mid 1970s. Feeding on grasslands has increased steadily since then, especially in east and southeast Ireland, with 25% of the population spending a large proportion of its time foraging on managed grasslands. In a few areas, most notably Wexford Slobs, Dungarvan Harbour and Strangford Lough, Light-bellied Brent Geese feed on cereal crops, both waste in autumn stubbles and spring seed, and waste potatoes. Although these food types remain available in early spring, most birds return to the saltmarshes at this time to exploit fresh growth of more natural foods prior to spring migration (Robinson et al. 2004).

    References

    Robinson, J.A., K. Colhoun, G.A. Gudmundsson, D. Boertmann, O.J. Merne, M. O’Briain, A.A. Portig, K. Mackie & H. Boyd. 2004. Light-bellied Brent Goose Branta bernicla hrota (East Canadian High Arctic population) in Canada, Ireland, Iceland, France, Greenland, Scotland, Wales, England, the Channel Islands and Spain 1960/61 – 1999/2000. Waterbird Review Series, The Wildfowl & Wetlands Trust/Joint Nature Conservation Committee, Slimbridge.

     

  • All-Ireland Light Bellied Brent Goose Census

    A complete census of the ECHA Light Bellied Brent Goose population is undertaken twice a year, one in autumn and one in spring. Counters record the number of geese present and the age structure of flocks. The census is organised by the Irish Brent Goose Research Group.

    Results from the census are summarised on the ‘Latest results’ tab.

    Find out more about the All-Ireland Light Bellied Brent Goose Census

  • Results for 2014/15 [added September 2015]

    Abundance

    A total of 31,985 Light-bellied Brent Geese were counted during a near-simultaneous census in the southern part of the wintering range in early November (UK, Ireland, France and Jersey). The current lack of aerial survey coverage in western Iceland means that an unknown number may have been present there, although the census date has been moved to a later date in order to try and minimise this. The total count, whilst possibly an undercount, continues a recent trend of counts falling within the range of 30–40,000 (Figure 1).

    Figure_ECHALB_1_2015Figure 1. Annual census-derived estimates of Canadian Light-bellied Brent Goose population size, 1960-2014. Five-year running mean shown as red line (e.g. mean for 2011 is from population estimates for 2009-2013).

    Breeding success

    The decrease in abundance is supported by the fact that 2014 was another poor breeding season, the third in succession. The population contained an estimated 4.1% young in a sample of almost 14,000 birds aged (Figure 2). The mean brood size was 2.1 young per family unit.

    Figure_ECHALB_2_2015Figure 2. The mean percentage of young (blue columns) and mean brood size (red circles) of East Canadian High Arctic Light-bellied Brent Geese, 1996/97-2014/15.

    Discussion

    Following a period of long-term growth, the Canadian Light-bellied Brent Goose population has shown signs of significant decline over recent years. A peak count of in excess of 48,000 in 2011 was inflated by high productivity (25.0%) in that season, but a series of poor breeding seasons since then (2012–2014 inclusive; mean 2.0%) has undoubtedly contributed to the lower census totals, in the range 30–40,000, during that period.

    However, the lack of an autumn survey in Iceland will inevitably have also contributed to the observed decline, meaning that these census totals are probably also an underestimate of actual population size. Thus, it is currently difficult to estimate population size for Canadian Light-bellied Brent Geese with any certainty. In an effort to minimise the effect of this reduced census coverage, we delayed the census date from the typical mid-October period to early November, in order to maximise the number of birds that had already migrated to Ireland or further south where surveys could be undertaken. Accordingly, the population was more dispersed than is usual for an autumn census and counts were received from a larger number of sites. Coverage was comprehensive throughout Ireland, western Scotland, Wales, western England, Jersey and northern France.

    Acknowledgements

    Thank you to Kendrew Colhoun and the Irish Brent Goose Research Group for providing the update, and to all the counters for their continued support.

  • Previous annual results will be archived here.

    2013/14 Results

    2012/13 Results (including 2011/12 results)

    2010/11 Results

    2009/10 Results

    2008/09 Results

    2007/08 Results

    2006/07 Results

    2005/06 Results

  • Background

    Colour-marking of this population began in 2001 and is overseen by the Irish Brent Goose Research Group. A large number of birds are currently colour-marked with engraved rings on each leg, and this underpins a range of detailed scientific studies also being carried out on this small, but increasing, population. Further details about this work can be found here.

  • Survey results

    Wetland Bird Survey Alerts

    Wetland Bird Survey annual report

    Relevant publications

    AEWA International Single Species Action Plan

    Northern Ireland Species Action Plan

    Robinson, J.A., K. Colhoun, G.A. Gudmundsson, D. Boertmann, O.J. Merne, M. O’Briain, A.A. Portig, K. Mackie & H. Boyd. 2004. Light-bellied Brent Goose Branta bernicla hrota (East Canadian High Arctic population) in Canada, Ireland, Iceland, France, Greenland, Scotland, Wales, England, the Channel Islands and Spain 1960/61 – 1999/2000. Waterbird Review Series, The Wildfowl & Wetlands Trust/Joint Nature Conservation Committee, Slimbridge. Download

    Other relevant material

    BirdLife International Species factsheet

    BirdWatch Ireland species information

    British Trust for Ornithology: BirdFacts

    Irish Brent Goose Research Group

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