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 7; Wetlands International 2015) 80,700 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. 2020) 25-year trend (1992/93-2017/18) = 126% increase
10-year trend (2007/08-2017/18) = 24% increaseSummary statistics
Table 1. Estimates of population size of Greenland Barnacle Goose, 1959-2018; recorded during the International Census of Greenland Barnacle Geese.
Census year Estimate of population size 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, 2004/05-2018/19; recorded on the isles of Islay, Scotland, where data have been collected regularly.
Season Percentage of young (%) Mean brood size 2018/19 1.1 1.01 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.M., N.A. Calbrade, G.A. Birtles, H.J. Mellan, C. Hall, A.E. Robinson,S.R. Wotton, D.E. Balmer & G.E. Austin. 2020. Waterbirds in the UK 2018/19: The Wetland Bird Survey. BTO, RSPB and JNCC, in association with WWT. British Trust for Ornithology, Thetford.
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.
Data access
Greenland Barnacle Goose data presented in Table 1 (Estimate of population 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. 2020. Goose & Swan Monitoring Programme: survey results for Greenland Barnacle Goose Branta bernicla. WWT/JNCC/NatureScot, Slimbridge” retrieved from https://monitoring.wwt.org.uk/our-work/goose-swan-monitoring-programme/species-accounts/greenland-barnacle-goose/ © 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.
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 2019/20 [added October 2020]
Abundance
International Census 2018
A flyway-wide census of Greenland Barnacle Geese took place in March 2018 (Mitchell & Hall 2020). The census was undertaken by WWT in Scotland, funded by NatureScot, and by the National Parks and Wildlife Service in Ireland. A brief summary of the results was presented in the 2017/18 report for Greenland Barnacle Goose: see earlier results tab.
The census yielded a population estimate of 72,162, a 10.5% decrease compared with the previous census in 2013 (80,670) (Figure 1). In Ireland, 16,237 birds were counted, a decrease of 7.2% compared with 2013, whilst a total of 55,424 birds was recorded for Scotland, representing a decrease of 11.5%.
Figure 1. Population estimates of Greenland Barnacle Goose, 1959 – 2018, derived from the International Barnacle Goose Census.
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. A full account of the 2020 census will be available in due course.
This census was carried out every five years but is likely to be ever three years in the future.
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 2019/20. These revealed 32,253 birds in November, 32,017 December, 34,795 in January and 33,202 in March. The mean of these four counts was 33,067 birds which represents a modest 3% increase compared to the winter 2018/19 mean (32,000 geese; Figure 2). The over-winter population there has now decreased by a third in the last four winters, likely as a result of the management culls that are taking place there.
Winter maxima at other key sites include 910 birds on Danna, Argyll (March), 1,146 on Coll, Argyll (March), 5,656 on Tiree (March), 2,579 on Orkney, 8,340 on North Uist (March) and 3,016 on Oronsay (December).
Figure 2. Adopted counts (mean of the winter counts) of Greenland Barnacle Geese on Islay, 2010/11–2019/20.
Breeding success
Breeding success is measured annually on Islay and counts in winter 2019/20 revealed an average breeding season. Just over 5,000 birds were aged and showed that 10.1% were young with a mean brood size of 2.04 young per successful pair (Table 1, Figure 3). On Tiree, a sample of 600 birds held 43 young (7.2%) with a mean brood size of 1.43 young per successful pair.
Table 1. The percentage of young and mean brood size of Greenland Barnacle Geese during winter 2019/20.
Site Number aged Percentage of young (%) Mean brood size Number of broods Islay 5,184 10.1 2.04 169 Tiree 600 7.2 1.43 30 Overall 5,784 9.8 1.95 199 
Figure 3. Percentage young (blue columns) and mean brood size (red circles) of Greenland Barnacle Goose on Islay (where data have been collected regularly), 1961/62–2019/20.
Discussion
The population total of this protected species has declined in the last five years and 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. The culls, carried out by NatureScot, are in response to perceived economic losses to the agriculture industry and are explained in the Islay Sustainable Goose Management Strategy.
Results from age assessments conducted during autumn 2019 on Islay (from where the largest sample is provided) show that the breeding season was above average; the figure of 10.1% young recorded in flocks on Islay being higher than the previous ten-year mean of 7.1% (± 1.57 SE). The long-term mean for the period 1961 to 2019 was 10.7% young. The mean brood size on Islay in 2019 was also slightly higher than average at 2.04 young per successful pair, compared to the previous ten-year mean of 1.77 young (± 0.12 SE). 2019 was however, only the second year when breeding success was higher than 10% young in the last eight years, and followed the worst breeding season since records began in 1959 (1.1% young recorded in 2018).
Acknowledgements
Thanks are extended to Malcolm Ogilvie and John Bowler for providing age counts. NatureScot provided additional counts.
References
Mitchell, C. & C. Hall. 2020. Greenland Barnacle Geese Branta leucopsis in Britain and Ireland: results of the international census, spring 2018. Scottish Natural Heritage Research Report No. 1154.
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
