speciesaccounts_barnaclegooseGreenland Barnacle Goose

 Branta leucopsis

The Greenland Barnacle Goose breeds in northeastern Greenland and winters almost entirely along the west coasts of Scotland and Ireland. The main concentration is found on the isle of Islay, Scotland, which regularly supports over 50% of the population.

Ringing studies have shown that Greenland Barnacle Geese are very faithful to specific wintering sites, with 70% of birds returning to the same site during the following winter.

  • 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)

    Least Concern

    B1

    Least Concern (Europe and EU27)

    Annex I

    Amber

    not huntable, but licensed control occurs in Scotland

    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)

    80,700 individuals

    58,000 individuals

    15,370 individuals

    Long-term trend (1988/89 – 2013/14): 146% increase
    Ten-year trend (2003/04 – 2013/14): 35% increase

    Highly variable, generally 3-13% during 1993-2011

    Summary statistics

    Estimates of population size of Greenland Barnacle Goose, 1959-2013; recorded during the International Census of Greenland Barnacle Geese.

    Census year Estimate of population size
    2013 80,670
    2008 70,501
    2003 56,386
    1999 54,123
    1994 38,012
    1988 34,542
    1983 25,252
    1978 33,815
    1973 24,082
    1966 19,797
    1962 13,990
    1961 13,904
    1959 8,321

    Annual estimates of the percenatage of young (%) and mean brood size (young per successful pair) of Greenland Barnacle Goose, 2004/05-2015/16; recorded on the isles of Islay and Tiree, Scotland.

    Season Percentage of young (%) Mean brood size
    2015/16 5.5 1.48
    2014/15 2.7 1.4
    2013/14 5.6 1.77
    2012/13 6.9 1.74
    2011/12 11.0 2.01
    2010/11 10.4 2.04
    2009/10 3.9 1.76
    2008/09 8.1 1.84
    2007/08 9.8 2.12
    2006/07 3.2 1.16
    2005/06 6.6 1.75
    2004/05 16.1 2.36

     

    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 Greenland population of Barnacle Goose breeds in northeastern Greenland. Migration begins in late August/early September, and birds use stop over sites in southeast Iceland. The geese begin to leave Iceland from late September and by November they have all reached the British and Irish wintering grounds. Ringing studies have shown that Greenland Barnacle Geese are very faithful to specific wintering sites, with 70% of birds returning to the same site during the following winter.

    flyway map barnacle_greenland

    Flyway of the Greenland Barnacle Goose

    The islands off the west and north coasts of Scotland and Ireland (as well as several mainland sites) support the entire population during the winter. The main concentration is on the island of Islay, with 78% of the Scottish total and 56% of the overall population occurring there in 2013 (Mitchell & Hall 2013). As numbers on Islay have steadily increased, some other key sites – notably Coll and Tiree (Inner Hebrides) and South Walls (Orkney) – have also become increasingly important, possibly as a result of an increase in intensively managed grasslands providing more favourable feeding habitat, as well as the establishment of Goose Management Schemes. Some smaller, uninhabited islands are now less used, possibly due to habitat changes possibly brought about by cessation of grazing. There have been some substantial changes in distribution since surveys began in 1957, when the population was equally divided between Islay, the rest of Scotland, and Ireland. Since then, numbers have increased on Islay which, in 2003, held 65% of the total population and 56% in 2013.

    Traditionally, saltmarshes, coastal pastures and islands were selected as favoured feeding areas, but more recently the requirement for short-cropped sward has been met by intensively managed grasslands. The geese feed on grasses, herbs, leaves, stolons and seeds, as well as barley and oat stubbles, spilt grain and undersown grass. Since the mid-twentieth centuray there has been an increase in the use of agricultural fields as feeding grounds. Most conflict occurs on Islay, as well as some of the other inhabited islands off the north and west coast of Scotland. To alleviate these conflicts, Goose Management Schemes are now in operation on Islay and South Walls, Orkney.

    References

    Mitchell, C., A. Walsh, C. Hall & O. Crowe. 2008. Greenland Barnacle Geese Branta leucopsis in Britain and Ireland: results of the international census, spring 2008. Wildfowl & Wetlands Trust, Slimbridge.

    Ogilvie, M.A., D. Boertmann, D. Cabot, O. Merne, S.M. Percival & A. Sigfusson. 1999. Barnacle Goose Branta leucopsis: Greenland. 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.

  • Annual counts and age assessments at key sites

    Due to many Greenland Barnacle Goose wintering sites being remote inaccessible islands, a complete census of the population is not possible every year, as aerial surveys are required to cover such areas. Annual counts are, however, undertaken at several key sites in Scotland. Two comprehensive counts are organised by Scottish Natural Heritage (SNH) on Islay, and monthly counts are also carried out by SNH at South Walls, Orkney. The RSPB undertake at least two counts during the winter on the Inner Herbridean isles of Coll, Tiree, Colonsay and Oronsay.

    Age assessments are also carried out on Islay and Tiree, where counters record the number of young present in flocks as well as individual brood sizes (i.e. the size of family groups).

    Results from these surveys are summarised on the ‘Latest Results’ tab.

    Find out more about age assessments

    International Census of Greenland Barnacle Goose

    A census of the entire Greenland Barnacle Goose population is undertaken every five years. The census covers Ireland and north and west Scotland and involves both ground counts and aerial surveys, the latter covering the inaccessible areas.

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

    Find out more about the International Census of Greenland Barnacle Geese

  • Results from 2015/16 [added August 2016]

    Abundance

    International Census 2013

    The most recent flyway-wide census of Greenland Barnacle Geese took place in March 2013, and included the remote parts of the winter range that need to be checked using a light aircraft. Flyway censuses are carried out once every five years. In Scotland, 226 sites were surveyed, including 190 islands by aerial census, and in Ireland, a further 72 sites were checked. Barnacle Geese were found at 38 sites in Scotland and 31 in Ireland. In total, 80,670 birds were counted, a 14.4% increase on the last complete census conducted in 2008 (70,501 counted). In Scotland, the total was 63,170 birds, an increase of 8.4% since 2008. Islay was the most important site with 44,914 birds – an almost identical count to the one recorded there five years previously. In Ireland, 17,500 birds were counted, an increase of 43% since 2008. The results from this census have been presented in Mitchell & Hall 2013.

    Figure_GBY_1_2015

    Figure 1. The population estimate of Greenland Barnacle Geese counted in Britain and Ireland from 1959 to 2013 (blue circles) based on periodic flyway censuses, shown with the total number counted on Islay (open red circles) at the time of the census.

    Annual counts at key sites

    Each winter, up to four comprehensive counts (where emphasis is placed on obtaining greatest coordinated coverage) are organised on Islay, the most important wintering site for Greenland Barnacle Geese, by Scottish Natural Heritage (SNH). The Islay population size is estimated from the mean of these counts and, in winter 2015/16, this figure was 42,838, 13.5% higher than the previous year (37,758 geese) (Figure 2).

    Figure_GBY_2_2016

    Figure 2. Adopted counts (mean of the winter counts) of Greenland Barnacle Geese on Islay, 2006/07-2015/16.

    Since 2006/07, the difference between the lowest summed counts at the six most important sites in Scotland excluding Islay (Figure 3) (11,289 in 2009/10) and the highest (15,166 in 2013/14) was only 3,877 birds, far fewer than the decrease in the number counted on Islay (of over 7,000 birds) over the same period. This suggests that the decline seen on Islay up to 2014/15 was real and that the birds had not simply moved to other winter resorts in Scotland.  Regular counts from Irish wintering sites are less frequent and there may have been a shift of geese from Islay to Ireland which merits further investigation.

    Figure_GBY_3_2016

    Figure 3. Winter peaks of Greenland Barnacle Geese at Uists, South Walls, Tiree, Coll, Colonsay/Oronsay and Danna, 2006/07-2015/16.

    Breeding success

    Breeding success in the population was assessed on Islay and Tiree. The Islay sample was much the larger (7,531 birds) and sampled flocks held 5.6% young, with a mean brood size of 1.51 young per successful pair (Table 1 and Figure 4). On Tiree, 500 birds were aged and these contained 4.6% young, with a mean brood size of 1.21 young (Table 1).

    Table 1. The percentage of young and mean brood size of Greenland Barnacle Geese during winter 2015/16.

    Site Number aged Percentage of young (%) Mean brood size
    Islay 7,531 5.6 1.51
    Tiree 500 4.6 1.21
    Overall 8,031 5.5 1.48

    Figure_GBY_4_2016

    Figure 4. Percentage young (blue columns) and mean brood size (red circles) of Greenland Barnacle Goose on Islay (where data have been collected regularly), 1961/62–2015/16.

    Discussion

    A small number of key sites in Scotland hold the majority of wintering Greenland Barnacle Geese, with the majority on the Inner Hebridean island of Islay. Combined numbers at the key sites, including Islay, underwent a sustained increase up to 2006/07; however, counts in the following winters indicated an apparent decrease in the size of the Scottish wintering population compared to the peak year. Up to c. 2,000 Greenland Barnacle Geese are shot in Iceland each year (mean 2005–2014; 1,614 birds) and licences to shoot up to 2,400 on Islay have been issued by the Scottish Government in recent years. It may be that this level of mortality, combined with relatively low annual productivity in the last ten years is keeping population growth in Scotland in check, and there may already be signs of a decrease in numbers wintering there. The increase in number on Islay of 13.5% compared to the previous winter is then surprising. However the mean figure (42,838) is influenced by a high count of 48,568 birds in November. Ring-recovery information has shown that November counts on Islay include some passage birds that stop over on Islay during the autumn and move on to winter elsewhere within the range. Excluding the high November count would give an average of 40,928 birds in 2015/16, a smaller increase of 8.4% on the previous winter. The peak count of Greenland Barnacle Geese on the six other important sites (i.e. Uists – Outer Hebrides, Tiree, Coll, Colonsay/Oronsay and Danna – Inner Hebrides; and South Walls on Orkney) declined by 3% from 14,579 to 14,053 suggesting that in 2015/16 more bird may have wintered on Islay than on the others important sites.

    Since a complete census of the entire population is carried out only once every five years, tracking the trend at the seven most important sites in Scotland (i.e. Islay and the six sites mentioned above) was, traditionally, thought to have reflected changes at the population level. However, the large difference in the rate of increase between Scotland (8.4%) and Ireland (43%) since the 2008 census suggests this may no longer be the case, and the annual counts in Scotland only allow us to track changes in the Scottish wintering population (which is approximately three quarters of the total population).

    Results from age assessments conducted during 2015/16 on Islay show that the 2015 breeding season was again poor; the figure of 5.6% young recorded on Islay being slightly lower than the previous ten-year mean of 6.9% (± 1.0 SE). Since 2006, annual breeding success has been below 10% in eight out of the ten years. Mean brood size on Islay in 2015 was also below average at 1.51 young per successful pair, lower than the previous ten-year mean of 1.81 young (± 0.1 SE). The reasons for the decline in breeding success on Islay are not known.

    Acknowledgements

    Thanks are extended to Malcolm Ogilvie and John Bowler for providing age counts. SNH provided additional counts.

    References

    Mitchell, C. & C. Hall. 2013. Greenland Barnacle Geese Branta leucopsis in Britain and Ireland: results of the international census, spring 2013. Wildfowl & Wetlands Trust Report, Slimbridge.

  • Previous annual results will be archived here. Published results from previous international censuses can be found on the Reports & newsletter page.

    2014/15 Results

    2013/14 Results

    2012/13 Results

    2011/12 Results

    2010/11 Results

    2009/10 Results

    2007/08 Results: including 2006/07 breeding success results

    2006/07 Results: including 2005/06 breeding success results

    2005/06 Results

  • Survey results

    International census reports: See the Reports & newsletter page

    Wetland Bird Survey Alerts

    Wetland Bird Survey annual report

    Relevant publications

    Mitchell, C., C. Hall & A. Douse. 2009. Greenland Barnacle Geese in Scotland in 2008. Scottish Birds 29: 99-100.

    Walsh, A.J. & O. Crowe. 2008. Barnacle Geese Branta leucopsis in Ireland, spring 2008. Irish Birds 8: 430-432.

    Other relevant material

    BirdLife International Species factsheet

    British Trust for Ornithology: BirdFacts

    Review of Goose Management Policy in Scotland 2010

    SNH Islay Goose Project

    Hunting in Iceland: The numbers of Greenland Barnacle Geese hunted in Iceland are available here.

gswmp_partners_198px