The use of agricultural fields by re-established greylag geese (Anser anser) in England: A risk assessment

Re-established greylag geese are currently increasing at a rate of 12% per annum, are non-migratory and can be observed grazing on agricultural fields. The risk of damage to UK agriculture was, therefore, assessed by counting birds seen feeding on crops during two surveys in Yorkshire, the Midlands and Norfolk, between 1999 and 2002. Numbers were highest and flock sizes greatest during the winter months (October to February). Field use increased with size (area) and proximity to water. During the breeding season (March through May) greylag geese were distributed in small flocks over a greater number of fields. Harvested root crops and grass were the preferred crops, rather than growing cereals. It seems, therefore, that grazing by re-established greylag geese does not currently have a large impact on agriculture in England. However, cereals are grazed in late winter and spring, often repeatedly, and by large flocks of geese, and there is, therefore, potential for economically significant yield loss should numbers continue to increase in the future.