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 (CSR 6; Wetlands International 2015)
GB estimate (Musgrove et al. 2011)
Irish estimate (Crowe & Holt 2013)
GB trend (SUKB 2016)
Breeding success (GSMP survey)
Long-term trend (1988/89 – 2013/14): 15% decrease
Ten-year trend (2003/04 – 2013/14): 8% 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 2016 90,471 23.5 2.53 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. & 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 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 2016/17 [August 2017]
The 57th consecutive Icelandic-breeding Goose Census (IGC) took place during late autumn 2016, 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 19/20 November. Coverage in Britain in November was average, with 102 sites checked (119 sites were checked the previous autumn). Outside Britain, counts were made at several sites in Iceland and southwest Norway. Counts in Norway took place in January rather than November, and the total from these counts was used as an estimated count for the November period.
The total count in November was 121,046 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 & Brides 2017), a population estimate of 90,471 was derived, and represented an decrease of 5.2% compared to 2015 (Figure 1), when a population size of 95,403 individuals was estimated.
During November, over half of the population was still in Iceland and 42.6% was present in North Scotland, principally in Orkney (Table 1).
Table 1. Regional distribution of Iceland Greylag Geese during November 2016 (nc = not counted or no count received).
Region November Iceland 50,000 Southwest Norway 700* Ireland nc** North Scotland 63,544 Northeast Scotland 1,561 East Central Scotland 2,421 Southeast Scotland/northeast England 860 Southwest Scotland/northwest England 1,960 Total Counted 121,046 Adjusted counts -32,588 Estimated counts +2,013 Adjusted total 80,090 Population estimate 90,471
*Count made in January 2017
**An estimate of 2,013 Greylag Geese was used, but 690 were suspected summering birds.
Figure 1. Annual census-derived estimates of Iceland Greylag Goose population size, 1960–2016. Five-year running mean shown as red line (e.g. mean for 2014 is from population estimates for 2012–2016).
During early December, 2,302 Greylag Geese from nine flocks were aged at various localities in Caithness. The sample, expressed as a proportion of the 2016 population estimate, was 2.5%. The brood size of 32 families was also determined during this period.
Breeding success was slightly higher than the recent mean, with flocks containing 23.5% young (mean 2006–2015: 22.0% ± 0.50 SE) (Figure 2). The mean brood size of 2.53 goslings per successful pair was slightly higher than that of the recent ten year mean (mean 2006–2015: 2.31 ± 0.09 SE).
Figure 2. The percentage of young (blue columns) and mean brood size (red circles) of Iceland Greylag Geese, 1960–2016.
The November 2016 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 reported and it is possible that the number of geese there, particularly in Northern Ireland, is greater than the estimate used. 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 90,471 geese is lower than that in 2015 and suggests 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) and, as reported in 2015, 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 winter stock. After deducting the number of Greylag Geese thought to be resident on the archipelago, based on a summer survey carried out in August 2016 (Mitchell et al. 2016), and taking account of those shot under a pilot management programme, an estimated 25,654 Iceland birds were thought to be present in November, a third lower than during the same month in the previous year (38,101). However, the Orkney count is influenced by the timing of the migration of birds from Iceland and, at the time of the November 2016 census, an estimated 50,000 birds still remained in that country. The vast majority of these birds will have left Iceland in the weeks following the census and migrated to Orkney to winter. Thus the over-winter population of Iceland Greylag Geese on Orkney is likely to be around 75,000 birds.
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 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 2016 (23.5%), although the figure was based on a small sample size. Age counts were only collected in one region (Caithness in North Scotland) during late November due to their later migration and more limited range. 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 in this county that age counts were undertaken.
The percentage of young in the Iceland bag in autumn 2016 was 56%, higher than the previous ten year average of 48% (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 and Arne Follestad from Norway.
Mitchell, C. & K. Brides. 2017. Status and distribution of Icelandic-breeding geese: results of the 2016 international census. Wildfowl & Wetlands Trust Report, Slimbridge. Download
Mitchell, C., A. Leitch & E. Meek. 2016. The abundance and distribution of British Greylag Geese in Orkney, August 2016. Wildfowl & Wetlands Trust Report, Slimbridge. 30pp. Download
Swann, R.L., .I.K. Brockway, M. Frederiksen, R. 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 in Ireland by Alan Lauder and several small catches on Islay, north west Scotland and on the breeding grounds in Iceland. Much of this work is focussed on questions about the status of Greylags in certain parts of Scotland and Ireland, where there is increasing overlap in winter range between British Greylag Geese and Icelandic birds, making monitoring more difficult.
Sightings of marked birds are still sought from birdwatchers. If you see a colour marked bird, please submit your sighting to firstname.lastname@example.org.
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.