Iceland Greylag Goose
The Iceland Greylag Goose breeds in Iceland and winters almost elusively in Britain, with smaller numbers in Ireland, Norway and the Faeroe Islands. Increasingly, some birds also remain in Iceland over winter.
Early analysis of ringing data confirmed that this population of Greylag Goose was discrete from others in the Western Palearctic, including the British-breeding population. Nowadays, however, there is some overlap between the Icelandic and British birds during the winter, notably in Orkney and Caithness.
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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 (Europe and EU27)
Annex II (Part A)
huntable during the open season
Flyway population size (Wetlands International 2015)
GB estimate (Musgrove et al. 2011)
Irish estimate (Crowe et al. 2008)
GB trend (SUKB 2014)
Breeding success (GSMP survey)
Long-term trend (1987/88 – 2012/13): 13% decrease
Ten-year trend (2002/03 – 2012/13): 16% increase
Proportion of young generally fluctuates between 10% and 25%
Annual estimates of the population size, percentage of young (%) and mean brood size (young per successful pair) of Iceland Greylag Goose, 2003-2015. Data are collected through the Icelandic-breeding Goose Census.
Autumn/winter Estimate of population size Percentage of young (%) Mean brood size 2015 95,403 20.4 2.73 2014 89,668 22.3 2.07 2013 88,577 22.2 2.23 2012 104,632 21.7 2.36 2011 111,558 19.6 1.92 2010 105,191 22.4 2.11 2009 105,947 21.9 2.26 2008 96,651 25.0 2.29 2007 100,630 21.7 2.61 2006 79,228 20.6 1.90 2005 95,664 22.7 2.30 2004 105,870 28.2 2.80 2003 80,802 20.5 2.73
Crowe, O., G.E. Austin, K. Colhoun, P.A. Cranswick, M. Kershaw & A.J. Musgrove. 2008. Estimates and trends of waterbird numbers wintering in Ireland, 1994/95 to 2003/04. Bird Study 55: 66-77.
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 Iceland population of the Greylag Goose was confirmed as being discrete from other Greylag Goose populations in the Western Palearctic, including the British-breeding population, by early analyses of ringing data. There is, however, some overlap between these populations during the winter, notably in Orkney and Caithness. This population breeds in lowland areas of Iceland. Each autumn, birds migrate to spend the winter almost exclusively in Britain. A small number of birds also winter in Ireland and the Faeroe Islands, and others have recently been identified in southern Norway.
Flyway of the Iceland Greylag Goose
Arrival in Britain begins in early autumn, particularly in north and east Scotland. Considerable redistribution used to occur later in the winter, especially to traditional haunts further south within Scotland and to northern England. Important changes in these patterns, however, since the 1970s means this rarely happens nowadays; there has been a clear contraction of range northwards and formerly important sites, especially in southern and central Scotland, have now been abandoned. Consequent increases have been most marked on Orkney, where winter numbers have increased from c. 3,000 in the early 1990s to a peak of over 60,000 in 2010 (Mitchell 2011). From early April, birds begin to leave Britain to return to the southern lowlands and other coastal areas of Iceland (Hearn & Mitchell 2004).
As little traditional winter habitat (coastal Scirpus beds and inland fens and marshes) remains in Britain today, the species has moved inland to feed on arable farmland and improved pastures. Many of these crops are of economic value and this has brought the geese into direct conflict with farmers. Farmers have tolerated geese for many years, but concern and the number of complaints have been growing, particularly where goose numbers are high and increasing, such as Orkney.
Hearn, R.D. & C.R. Mitchell. 2004. Greylag Goose Anser anser (Iceland population) in Britain and Ireland 1960/61 – 1999/2000. Waterbird Review Series, The Wildfowl & Wetlands Trust/Joint Nature Conservation Committee, Slimbridge.
Mitchell, C. 2011. Status and distribution of Icelandic-breeding geese: results of the 2010 international census. Wildfowl & Wetlands Trust Report, Slimbridge.
Icelandic-breeding Goose Census
The Iceland Greylag Goose population is monitored through the Icelandic-breeding Goose Census; an international census undertaken in Britain, Ireland, Iceland, Norway and the Faeroe Islands. The census is undertaken annually and involves coordinated counts carried out in autumn and early winter.
Results from the census are presented in various reports which can be downloaded from the Reports & newsletter page.
Find out more about the Icelandic-breeding Goose Census
GSMP age assessments
The annual breeding success of the Iceland Greylag Goose population is monitored through age assessments that are undertaken annually throughout the autumn and early winter. 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 from these age assessments are presented on the ‘Latest results’ tab, and a summary table can also be found on the ‘Status summary’ tab.
Find out more about age assessments
Results for 2015/16 [August 2016]
The 56th consecutive Icelandic-breeding Goose Census (IGC) took place during late autumn 2015, providing information on the abundance and distribution of Iceland Greylag Geese. Counts were conducted by a network of volunteer observers and professional conservation staff over the weekend of 14/15 November. Coverage in Britain was good, with 119 sites checked. Outside Britain, counts were made at several sites in Ireland, southwest Norway (no counts of Greylag Geese were made in southwest Norway during November, however, 502 birds, the number counted there in January 2016, was used as an estimated count for the November period since the counter considered little movement or addition of birds once the wintering flock had arrived) and Iceland.
The total count in November was 116,330 Greylag Geese (Table 1). Following adjustments for the presence of British Greylag Geese, which is significant in some areas, and the addition of estimated counts (for definitions and methods see full report, Mitchell 2016), a population estimate of 95,403 was derived. This represents an increase of 6.4% compared to 2014/15 (Figure 1), when a population size of 89,668 individuals was estimated.
At the time of the census, 68.4% of the population was present in north Scotland, with most of the remainder in Iceland (24.3%).
Table 1. Regional distribution of Iceland Greylag Geese during November 2014 (nc = not counted).
Region November Iceland 35,000 Southwest Norway 502* Ireland 1,368 North Scotland 73,732 Northeast Scotland 1,537 East Central Scotland 2,719 Southeast Scotland/northeast England 645 Southwest Scotland/northwest England 827 Total Counted 116,330 Adjusted counts -27,665 Estimated counts +6,738 Adjusted total 95,403 Population estimate 95,403
*Count made in January 2016
Figure 1. Annual census-derived estimates of Iceland Greylag Goose population size, 1960-2015. Five-year running mean shown as red line (e.g. mean for 2013 is from population estimates for 2011-2015).
During early December, 2,512 Greylag Geese from 10 flocks were aged at various localities in Caithness. The sample, expressed as a proportion of the 2015 population estimate, was 2.6%. The brood size of 30 families was also determined during this period. Breeding success was slightly below the recent mean, with flocks containing 20.4% young (mean 2005–2014: 22.2% ± 0.71 SE) (Figure 2). The mean brood size of 2.73 goslings per successful pair was slightly higher than the recent ten year mean (mean 2005–2014: 2.27 ± 0.08 SE).
Figure 2. The percentage of young (blue columns) and mean brood size (red circles) of Iceland Greylag Geese, 1960-2015.
The November 2015 count of Iceland Greylag Geese was thought to be reasonably comprehensive with sites being covered throughout most of the winter range. Coverage in Ireland was not complete (compared with an extensive survey carried out there in autumn 2007) and it is possible that the number of geese in Ireland, particularly in Northern Ireland, is greater than reported here. No count was carried out in the Faroes although the number of overwintering Greylag Geese there is currently unknown and those that are present may be residents.
The population estimate of 95,403 geese is slightly higher than that in 2014 and suggests a stabilisation in numbers, although there has been a recent decline from over 100,000 birds (as recently as 2012). Greylag Goose remains a favoured quarry species in Iceland, with 30,000 to 60,000 birds shot there annually (43,000 in 2014; mean 2005-14 42,928) and, as reported last year, there has been a marked increase in the number of Greylag Geese shot in Orkney to reduce the British Greylag Goose population on the archipelago, and it is therefore highly likely that more Iceland migrants are being shot there too.
Orkney continues to hold the bulk of the population during winter. After deducting the number of Greylag Geese thought to be resident on the archipelago, based on a summer survey carried out in August 2015 (Mitchell et al. 2015), and taking account of those shot under a pilot management programme, an estimated 38,101 Iceland birds were thought to be present in November, 17% lower than during the same month in the previous year (45,881). However, the Orkney count is influenced by the timing of the migration of birds from Iceland, and at the time of the November 2015 census, an estimated 35,000 birds still remained in that country, although the majority of these will have left in the weeks following the census and migrated to Orkney to winter. According to the traditional Iceland ‘Christmas’ bird counts, only 2,135 Greylag Geese (2.2% of the November population estimate) were counted in that country in early January 2016. For the first time, three Orkney islands were not counted and estimates, based on the mean count in the previous five years, were provided for Stronsay (5,096), Westray (1,196) and Egilsay (446).
Increasing numbers of British Greylag Geese in core wintering areas for the Iceland migrants, such as Shetland, Orkney, the Moray Firth, Bute and other parts of Scotland and Ireland means that assessing the abundance of the Iceland migrants remains difficult. Where there are reasonable estimates of the abundance of summering Greylag Geese (for example on Orkney) these are subtracted from winter counts. However, up to date information on the abundance of British Greylag Geese south and east of an arbitrary line from Bute east to Aberdeen is largely lacking and, simply as a precaution, any counts obtained through IGC from this area are matched by subtracting that figure (assuming that the majority of birds counted are British). This is unsatisfactory, and is only carried out as a precautionary measure. An analysis of movements of Iceland Greylag Geese based on sightings of individually marked birds in the late 1990s/early 2000s showed that some Iceland migrants moved south within Scotland to winter (Swann et al. 2005). It is not known if this is still the case since ringing of the population stopped in the mid 2000s. It is highly likely that a small proportion of Iceland migrants do still move south to winter in south east Scotland, but since the proportion is unknown, a precautionary approach has been adopted.
Breeding success in the Iceland Greylag Goose population, as measured on the wintering grounds, appeared to be average in 2015 (20.4%), although the figure was based on a small sample size. Due to their later migration and more limited range, age counts were only collected in one region (Caithness in North Scotland) during early December. Monitoring annual breeding success for this population is becoming more difficult because the main wintering areas (Orkney, Caithness and around the Moray Firth) hold ever larger numbers of British Greylag Geese and separating birds from each population is impossible in the field. However, the results from summer counts suggest that the bulk of the birds found in Caithness in winter are from Iceland and it is therefore in this county that age counts were undertaken. The percentage of young in the Iceland bag was 44.2%, slightly lower than the previous ten year average of 47.4% (A. Sigfússon in litt.). The population dynamics of this population merit greater study since the population must sustain one of the highest rates of annual mortality through hunting of any goose population and is balanced, presumably, by particularly high rates of breeding success. The long term dynamics of populations that can sustain such mortality would be of particular interest to those wishing to control the abundance of goose populations.
As ever, thanks are extended to the many IGC counters who provided the basis of the population assessments. Of particular importance is the role of the Local Organisers. G. Gudmundsson and A. Sigfússon provided information from Iceland, Helen Boland from Birdwatch Ireland, Helga Bára Mohr Vang from Faroes and Arne Follestad from Norway.
Mitchell, C. 2015. Status and distribution of Icelandic-breeding geese: results of the 2014 international census. Wildfowl & Wetlands Trust Report, Slimbridge.
Mitchell, C., A. Leitch & E. Meek. 2014. The abundance and distribution of British Greylag Geese in Orkney, August 2014. Wildfowl & Wetlands Trust Report, Slimbridge.
Swann, RL, I.K. Brockway, M. Frederiksen, R.D. Hearn, C. Mitchell & A. Sigfússon. 2005. Within-winter movements and site fidelity of Icelandic Greylag Geese Anser anser. Bird Study 52: 25-36.
Previous annual results will be archived here. Annual Icelandic-breeding Goose Census reports can be found on the Reports & newsletter page.
The colour-marking of Iceland Greylag Geese began in earnest in the early 1990s, when Highland Ringing Group (led by Bob Swann), supported by WWT, began to cannon-net birds and mark them with grey neck collars at Loch Eye, near Tain. This provided the first understanding of how Iceland Greylags moved around the wintering grounds. In 1996, WWT and the Icelandic Institute of Natural History began a five year marking programme, capturing around 1,000 birds (moulting adults and goslings) at breeding and moulting sites in Iceland. Other British ringing groups also contributed to the capture and marking at this time, most notably the Grampian Ringing Group. This collective effort resulted in a large dataset of re-encounters of marked birds, and a number of papers were published using this information, including analyses of winter movements (Swann et al. 2005), and survival rates (Frederiksen et al. 2004).
More recently, fewer birds have been marked, but targeted marking of small numbers continues to take place and sightings of these birds are still sought from bird watchers. Much of this work is focussed on questions about the status of Greylags in certain parts of Britain and Ireland, where there is increasing overlap in winter range between British Greylag Geese and Icelandic birds, making monitoring more difficult, such as Shetland and parts of Ireland.
Sightings of marked Greylag Geese in Britain and Ireland can be submitted to email@example.com.
Frederiksen, M., R.D. Hearn, C. Mitchell, A.Þ. Sigfússon, R.L. Swann & A.D. Fox. 2004. The size and dynamics of Icelandic-breeding goose populations: a reassessment of the evidence. Journal of Applied Ecology 41: 315-334.
Swann, R.L., I.K. Brockway, M. Frederiksen, R.D. Hearn, C. Mitchell & A. Sigfússon. 2005. Within-winter movements and site fidelity of Icelandic Greylag Geese Anser anser. Bird Study 52: 25-36.
Icelandic-breeding Goose Census reports: See the Reports & newsletter page
Hearn, R.D. & C.R. Mitchell. 2004. Greylag Goose Anser anser (Iceland population) in Britain and Ireland 1960/61 – 1999/2000. Waterbird Review Series, The Wildfowl & Wetlands Trust/Joint Nature Conservation Committee, Slimbridge. Download
Mitchell, C. 2012. Mapping the distribution of feeding Pink-footed and Iceland Greylag Geese in Scotland. Wildfowl & Wetlands Trust / Scottish Natural Heritage Report, Slimbridge. Download
Other relevant material
Hunting in Iceland: The numbers of Greylag Geese hunted in Iceland are available here.