speciesaccounts_lightbelliedbrentgooseEast Atlantic Light-bellied Brent Goose

Branta bernicla hrota

The East Atlantic population of Light-bellied Brent Goose breeds on Svalbard, Franz Josef Land and northeast Greenland and winters primarily in Denmark and at Lindisfarne, northeast England.

  • 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*

    A1c

    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)

    GB trend (SUKB 2016)

    Breeding success (GSMP survey)

    7,300 individuals

    3,400 individuals

    Long-term trend (1988/89 – 2013/14): 77% increase
    Ten-year trend (2003/04 – 2013/14): 13% decrease

    Marked fluctuations, ranging 5-31%.

    Summary statistics

    Annual estimates of the percentage of young (%) and mean brood size (young per successful pair) of East Atlantic Light-bellied Brent Goose, 2005/06-2013/14; recorded at Lindisfarne, Northumberland.

    Season Percentage of young (%) Mean brood size
    2014/15 6.3
    2013/14 4.2
    2012/13 7.6
    2011/12 4.9
    2010/11 11.6
    2009/10 2.2 1.80
    2008/09 2.0 1.67
    2007/08 13.6 2.24
    2006/07 2.5 2.50
    2005/06 6.5 2.12

     

    Reference

    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 Atlantic population of Light-bellied Brent Goose (also known as the ‘Svalbard/North Greenland’ population) breeds on Svalbard, Franz Josef Land and northeast Greenland and winters primarily in Denmark and at Lindisfarne, northeast England. The geese stop over in Denmark in spring, before embarking on the longest unbroken migration of any Western Palearctic goose, to breeding grounds in the high Arctic that are further north than those of any other goose population. Post-breeding and non-breeding birds moult in the Arctic, before migrating direct to Denmark or England.

    flyway map brent_EALB

    Flyway of the East Atlantic Light-bellied Brent Goose

    Traditionally, the main wintering sites were Mariager & Randers Fjords in Denmark, but Lindisfarne has become increasingly important with numbers increasing from 200 individuals in the 1950s, to over 3,000 in the 2000s and over 4,000 in the early 2010s. Occasionally, during severe weather in Denmark, up to 80% of the population occurs at Lindisfarne. In recent years, they have been arriving at these wintering sites increasingly early, with a corresponding decrease in the use of the previous main autumn staging area in the Danish Wadden Sea (Denny et al. 2004).

    By mid to late winter, most birds have moved from the wintering sites to spring staging areas in Denmark, primarily at Nissum Fjord and increasingly at Agerø and several other sites. At this time the whole population is found in Denmark. Evidence suggests that many may stop over at non-breeding sites in Svalbard before moving to the breeding areas (Denny et al. 2004).

    Until recently, Light-bellied Brent Geese only used what may be regarded as natural habitats, feeding on intertidal and subtidal seagrass (Zostera and Ruppia) and algal (Enteromorpha and Ulva lactuca) beds and saltmarshes. Since 1991, however, they have started feeding on agricultural land at many of their wintering/spring sites, using autumn-sown cereals, pastures and spring-sown cereal seeds. In some areas this has lead to conflicts with agricultural interests (Clausen et al. 1999).

    References

    Clausen, P., J. Madsen, S.M. Percival, G.Q.A. Anderson, K. Koffijberg, F. Mehlum & D. Vangeluwe. 1999. Light-bellied Brent Goose Branta bernicla hrota: Svalbard. In: Madsen, J., G. Cracknell & A.D. Fox (eds.). 1999. Goose populations of the Western Palearctic. A review of status and distribution. Wetlands International Publication no. 48, Wetlands International, Wageningen, The Netherlands/National Environmental Research Institute, Ronde, Denmark.

    Denny, M.J.H., P. Clausen, S.M. Percival, G.Q.A. Anderson, K. Koffiberg & J.A. Robinson. 2004. Light-bellied Brent Goose Branta bernicla hrota (East Atlantic population) in Svalbard, Greenland, Franz Josef Land, Norway, Denmark, the Netherlands and Britain 1960/61 – 2000/01. Waterbird Review Series, The Wildfowl & Wetlands Trust/Joint Nature Conservation Committee, Slimbridge.

     

  • Wetland Bird Survey

    The abundance of the EA Light-bellied Brent Goose population in the UK is monitored through the Wetland Bird Survey (WeBS). The results from the survey are published in an annual report (see the WeBS website for details).

    GSMP age assessments

    Age assessments of EA Light-bellied Brent Geese are undertaken annually at Lindisfarne, Northumberland, with counts carried out between September and March. 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 of the age assessments can be found on the ‘Latest results’ tab.

    Find out more about age assessments

  • Results for 2014/15 [added September 2015]

    Abundance

    The abundance of East Atlantic Light-bellied Brent Geese in the UK during 2014/15 was monitored through the Wetland Bird Survey (WeBS). Results are presented in survey reports that are available on the WeBS website.

    Breeding success

    Age assessments were undertaken at two sites in Britain, Lindisfarne (Northumberland) and Nairn (Highlands), between January and March 2015. A combined total of 107 birds were aged at the sites in January, of which 8.4% were young. The largest sample was taken at Lindisfarne in February, when 249 geese were aged with the flock comprising of 6.4% young (Figure 1). Only 20 geese were aged at Nairn in March, which included one young bird. No brood size data were collected in 2014/15. Taking the two largest samples for each site results in an overall breeding success of 6.3% young amongst flocks in Britain.

    Outside of Britain, a total of 895 birds were aged in Denmark during October, with flocks containing 16.2% young (Figure 1) and a mean brood size of 2.19 young per successful pair (n=19). Combining counts undertaken in Britain in February and March with samples from two Danish sites visited in March revealed a post-winter overall breeding success of 8.9%.

    Figure_EALB_1_2015Figure 1. Percentage of young  (blue columns) and mean brood size (red circles) of East Atlantic Light-bellied Brent Geese in Britain, and the percentage young for the flyway population (blue columns), 2005/06-2014/15.

    Discussion

    Results from age assessments of East Atlantic Light-bellied Brent Geese made in Britain indicate that breeding success was similar to the previous ten-year mean (6.1% young) and slightly higher than the previous year (4.2%).

    Results from counts made elsewhere in the flyway indicate an above average breeding success for the population as a whole in 2014/15 (average of 10% young for 2004/05–2013/14). However, the decline from 16.2% young to 8.9% between October and February/March suggests that almost half the young birds, some 576, may have died over winter. It is, however, known that family groups tend to cluster together soon after the autumn migration and the percentage young may have been overestimated in October or alternatively underestimated in February/March.

    To confirm whether this is the case will require an alternative mortality estimate to be calculated, based on apparent survival rates. This will be done after the October 2015 count, when the number of adults in early autumn will be compared with the previous season’s total population size: the difference will suggest the number of birds that have probably died.

    These mortality estimates are calculated on an annual basis following methods and formulae given in Clausen et al. 1998. In 1998, the average annual recruitment was estimated as 14.5% young, and for 1980/81–1994/95 the estimated mortality rate was 12.7%. This suggested the potential for a 1.8% positive growth rate per annum (Clausen et al. 1998). However, for the period 2005/06–2014/15, the average recruitment rate was 10.3% young and the estimated mortality rate was 10.8%, resulting in a current annual growth rate of -0.5%.

    The lower mortality rate seen in the most recent ten years probably reflects the geese having experienced fewer severe winters compared to previous years; whereas, the reasons for the lower breeding success is not fully understood. However, it may be explained by observed phenological mismatches in Svalbard (Clausen & Clausen 2013) or perhaps increased competition with Barnacle Geese in Svalbard or observed longer flight distances to the breeding grounds. The two latter hypotheses are subject to current research.

    Acknowledgements

    Our thanks go to Preben Clausen and Andrew Craggs for the data and the update, and also to Derek Forshaw, Simon Foster, Henrik Haaning Nielsen, Keld Henriksen, Jens Peder Hounisen and Kevin Clausen for contributing to the age counts.

    References

    Clausen, P., J. Madsen, S.M. Percival, D. O’Connor & G.Q.A. Anderson. 1998. Population Development and Changes in Winter Site Use by The Svalbard Light-Bellied Brent Goose, Branta bernicla hrota 1980–94. Biological Conservation 84: 157–165.

    Clausen, K.K. & P. Clausen. 2013. Earlier Arctic springs cause phenological mismatch in long-distance migrants. Oecologia 173: 1101–1112.

  • Previous annual results will be archived here.

    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

  • Survey results

    Wetland Bird Survey Alerts

    Wetland Bird Survey annual report

    Relevant publications

    Denny, M.J.H., P. Clausen, S.M. Percival, G.Q.A. Anderson, K. Koffiberg & J.A. Robinson. 2004. Light-bellied Brent Goose Branta bernicla hrota (East Atlantic population) in Svalbard, Greenland, Franz Josef Land, Norway, Denmark, the Netherlands and Britain 1960/61 – 2000/01. Waterbird Review Series, The Wildfowl & Wetlands Trust/Joint Nature Conservation Committee, Slimbridge. Download

    Other relevant material

    Blog on migration tracking by Danish researchers

    BirdLife International Species factsheet

    British Trust for Ornithology: BirdFacts

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