Greenland 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) Least Concern African-Eurasian Waterbird Agreement (AEWA) B1 European status (European Red List of Birds) Least Concern (Europe and EU27) The Birds Directive (European Commission) Annex I UK status (Birds of Conservation Concern) Amber UK quarry species (Wildlife & Countryside Act 1981) not huntable, but licensed control occurs in Scotland Population Status
Flyway population size (CSR 8; Wetlands International 2021) 72,000 individuals UK estimate (APEP 4) 56,000 individuals GB estimate (Frost et al. 2019) 56,000 individuals All-Ireland estimate (Burke et al. 2018) 16,240 individuals UK trend (Frost et al. 2021) 25-year trend (1993/94-2018/19) = 115% increase
10-year trend (2008/09-2018/19) = 23% increaseSummary statistics
Surveys for the International Census of Greenland Barnacle Geese are funded and organised in Ireland by the National Parks & Wildlife Service (NPWS), and in Scotland by NatureScot and WWT.
Table 1. Estimates of population size of Greenland Barnacle Goose, 1959-2020; recorded during the International Census of Greenland Barnacle Geese (e.g. Mitchell & Hall 2020).
Census year Estimate of population size 2020 73,391 2018 72,162 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 Table 2. Annual estimates of the percentage of young (%) and mean brood size (young per successful pair) of Greenland Barnacle Goose, 2004/05-2020/21; recorded on the isles of Islay, Scotland, where data have been collected regularly.
Season Percentage of young (%) Mean brood size 2020/21 9.8 1.92 2019/20 9.8 1.95 2018/19 1.1 1.02 2017/18 5.3 1.92 2016/17 17.9 2.21 2015/16 5.6 1.51 2014/15 2.7 1.40 2013/14 5.5 1.78 2012/13 7.0 1.80 2011/12 11.2 2.10 2010/11 11.2 2.26 2009/10 4.0 1.80 2008/09 8.2 1.86 2007/08 9.8 2.12 2006/07 3.2 1.16 2005/06 6.6 1.76 2004/05 15.9 2.35 References
Burke, B., L.J. Lewis, N. Fitzgerald, T. Frost, G.E. Austin & T.D. Tierney. 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.
Mitchell, C. & C. Hall. 2020. Greenland barnacle geese Branta leucopsis in Britain and Ireland: Results of the International census, spring 2020. NatureScot Research Report.
Wetlands International. 2021. Waterbird population estimates. Retrieved from http://wpe.wetlands.org/ September 2021.
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 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 2020/21 [added September 2021]
Abundance
International Census 2020
The most recent flyway-wide census of Greenland Barnacle Geese took place in March 2020. The census was undertaken by WWT in Scotland, funded by NatureScot, and by the National Parks and Wildlife Service in Ireland. The census was undertaken just before the Covid-19 lockdown period.
The population estimate was 73,391, a 1.7% increase on the last complete census conducted in 2018 (72,162) (Figure 1). In Ireland, 15,256 birds were counted, a decrease of 6.0% since 2018. In Scotland, 189 sites were surveyed, including 157 islands by aerial census and Barnacle Geese were found at 38 sites (Figure 2). A total of 58,135 birds was counted, an increase of 4.0% since 2018.
Islay was the most important site with 33,202 birds counted (Table 1), 4.5% lower than the number recorded there two years previously. Compared to 2018, there were increases in numbers in areas outwith Islay; numbers on Tiree and Coll increased by 5.0% to 6,802 birds, on Colonsay/Oronsay, numbers increased by 27.5% to 2,868 and, on North Uist (mainland), numbers increased by 40.0% to 8,340.
Figure 1. Population estimates of Greenland Barnacle Goose, 1959–2020, derived from the International Barnacle Goose Census.
Figure 2. The distribution of Greenland Barnacle Geese in Scotland recorded during the mid-March 2020 international census.
Table 1. Counts of over 1% of the Scottish total of Greenland Barnacle Geese made during the March 2020 survey (Mitchell & Hall 2020).
Site Area Count in 2018 Count in 2020 % change Islay Argyll 34,750 33,202 -4.5 Tiree Argyll 5,126 5,656 10.3 Oronsay/Colonsay Argyll 2,250 2,868 27.5 Paible/Balemore North Uist 1,442 2,640 83.1 South Walls Orkney 1,460 1,738 19.0 Berneray North Uist 745 1,467 96.9 Coll Argyll 1,266 1,146 -9.5 Grenitote/Sollas/Malaclate North Uist 325 1,076 231.1 Newton North Uist 231 965 317.1 Eilean Mor Argyll 1,1801 915 -22.5 Balranald North Uist 677 910 34.4 South Ronaldsay Orkney 231 737 219.0 1 2018 value is the combined count of 650 at Danna (Argyll) and 530 birds at Luing (Argyll). No Greenland Barnacle Geese were recorded at either site during the 2020 census, but 915 birds were recorded on Eilean Mor, an island just to the south of Danna. It is possible that the Eilean Mor flock comprised birds from both Danna and Luing, due to disturbance at both sites.
Note; a complete census report will be made available by NatureScot in due course.
Annual counts at key sites
On Islay, the most important wintering site in the UK for Greenland Barnacle Geese, four co-ordinated counts were undertaken during winter 2020/21. These revealed 34,381 birds in November, 32,107 December, 37,364 in January and 29,798 in March. The low figure in March 2021 could have been associated with periods of cold weather earlier in the winter driving geese to Ireland or others sites in Scotland. The mean of these four counts was 33,413 birds which represents a modest 1% increase compared to the winter 2019/20 mean (33,067 geese) (Figure 3).
Winter maxima at other key sites include 700 birds on Danna, Argyll (March), 7,416 on Coll & Tiree, Argyll (March) and 2,753 on Colonsay/Oronsay (December).
Figure 3. Adopted counts (mean of the winter counts) of Greenland Barnacle Geese on Islay, 2011/12–2020/21.
Breeding success
Breeding success is measured annually on Islay and counts in winter 2020/21 revealed a below average breeding season. Just over 4,000 birds were aged there of which 9.55% were young, and a mean brood size of 2.05 young per successful pair was recorded (Table 1, Figure 4). The percentage of young recorded on Islay has been over 10% in only three of the last ten years.
On Tiree, a sample of 500 birds held 61 young (12.2%) with a mean brood size of 1.65 young per successful pair (Table 1).
Table 1. The percentage of young and mean brood size of Greenland Barnacle Geese during winter 2020/21.
Site Number aged Percentage of young (%) Mean brood size Number of broods Islay 4,010 9.55 2.05 83 Tiree 500 12.2 1.65 37 Overall 4,510 9.84 1.92 120 
Figure 4. Percentage young (blue columns) and mean brood size (red circles) of Greenland Barnacle Goose on Islay (where data have been collected regularly), 1961/62–2020/21.
Discussion
The population total of this protected species has declined in the last seven years from 80,670 birds in 2013 to 73,391 in 2020. This is probably due to increased mortality through legal hunting in Iceland and the culls on Islay which have increased, at a time when annual reproductive success has been low. Despite the monthly fluctuations in counts, the between year means suggest that winter numbers on Islay have stabilised. The over-winter population there has, however, decreased by a third in the last five winters as a result of the management taking place there. In winter 2020/21 a further 805 Greenland Barnacle Geese were shot on Islay.
Results from age assessments conducted during autumn 2020 on Islay (from where the largest sample is provided) show that the preceding breeding season was again just below the long term average; the figure of 9.55% young recorded in flocks on Islay was, however, higher than the previous ten-year mean of 7.76% (± 1.56 SE). The long term mean for the period 1961 to 2019 was 10.7% young. The mean brood size on Islay in 2020 was slightly higher than average at 2.05 young per successful pair, compared to the previous ten-year mean of 1.8 young (± 0.12 SE).
Acknowledgements
Thanks are extended to Malcolm Ogilvie and John Bowler for providing age counts, and to NatureScot for providing the additional counts.
References
Mitchell, C. & C. Hall. 2020. Greenland barnacle geese Branta leucopsis in Britain and Ireland: Results of the International census, spring 2020. NatureScot Research Report.
Previous annual results will be archived here. Published results from previous international censuses can be found on the Reports & newsletter page.
2007/08 Results: including 2006/07 breeding success results
2006/07 Results: including 2005/06 breeding success results
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
Wetland Bird Survey report online
BirdLife International Species factsheet
British Trust for Ornithology: BirdFacts
Review of Goose Management Policy in Scotland 2010
Hunting in Iceland: The numbers of Greenland Barnacle Geese hunted in Iceland are available here.
SNH Islay Sustainable Goose Management Strategy
SNH Islay Goose Management Scheme
