Migratory geese foraging on grassland: Case study in the region of Flanders (Belgium)

Every winter nearly 100 000 migratory geese visit Northwestern Flanders (Belgium), including several protected species such as the pink-footed goose (Anser brachyrhynchus). The geese mainly forage on agricultural grassland, where they remove all the green parts and leave substantial amounts of droppings. In 2009 several farmers’ concerns about this phenomenon were thoroughly investigated. The main findings revealed that grass production on grazed parcels is reduced by 450 kg DM/ha on average at the time of the first cut around 1 May. On the same parcels, soil nitrogen addition from goose droppings did not far exceed 10 kg/ha, a small amount in comparison to the farmers’ average annual fertilization rate. No negative effect on grass fodder quality was found; even a small but significant increase in crude protein content was observed as well as a decrease in crude fibre content. The results of this study laid the foundation for measuring grass yield losses due to grazing by protected wildlife species, now used in a compensation scheme for farmers.