Paterson I.W. (1991) The status and breeding distribution of Greylag Geese Anser anser in the Uists (Scotland) and their impact upon crofting agriculture. ARDEA 79 (2): 243-251

The resident population of Greylag Geese on the Scottish islands of North Uist, Benbecula and South Uist forms a significant proportion of the wild British population. The Uists' population has doubled since the 1960s. This led to increased complaints from farmers of significant losses to ripening cereal crops and damage to spring pastures by grazing geese. Grazing intensities were estimated from faecal pellet densities; herbage losses were calculated indirectly from pellet densities and grass digestibility. Pellet densities fluctuated, with peaks of grazing intensity during the new moon. Generally pellet densities were low and herbage losses were too small to affect spring grass production. In 6 cases of measurable damage to ripening cereal crops, 5 had losses greather than 5% of the expected yield. Crops affected ranged from 0.1-6 ha, so the weights of lost fodder carried accordingly. The largest loss was of 10.8 tonnes of fodder. The number of cases of cereal damage and their severity varied from year to year, depending upon the weather conditions and timing of the harvest. Years with long protracted harvests offered the greatest opportunity for damage.