Status and population viability of Icelandic Greylag Geese Anser anser in Scotland

During 2003–2007, the Icelandic Greylag Goose Anser anser population increased from c. 73,000 to c. 100,000 individuals (reversing a decline in numbers recorded during the 1990s), the wintering distribution shifted northwards (c. 60 % to Orkney) and breeding success (the proportion of adults which successfully raised young) increased. Count, productivity and re-sighting data were analysed to identify any important relationships between the demographic variables (survival and productivity) influencing population trends and intrinsic and extrinsic covariates. In particular, a population model was developed to permit exploration of the effects of recent changes in UK shooting pressure and predict how the population may respond to possible future shooting scenarios. The model suggested that the shooting of Icelandic Greylag Geese in the UK has declined since 1999, to the extent that by 2007 around 8,000 fewer birds were being shot annually there, probably as a consequence of northward shifts in wintering distribution. Model projections based on this reduced shooting level predicted a median population size of c. 220,000 birds after 25 years, with no risk of decline t