Management of the Great Linford Canada and Greylag Goose populations 1972-1989.
Canada geese are now a common and widespread bird of sand and gravel pits and public car parks in the south of England. The population has grown steadily at an average rate of 8% over the past 30 years (Ogilvie 1977, Owen et al 1986) . An important feature of the British population is that it is widely distributed, with reports of the species at over 1000 sites, but with more than 70% of sites having fewer than 25 birds. The species spreads very rapidly, readily adapting to new breeding habitat, particularly islands on restored gravel pits complexes (Wright and Giles 1988) . The continuing extraction of aggregates from the floodplains of the rivers Thames, Great Ouse and Trent, therefore, has provided ideal breeding habitat adjacent to good feeding areas on neighbouring agricultural and amenity land.
Inevitably feeding flocks of Canada geese in winter and particularly in early spring have prompted a barrage of complaints of crop damage from local farmers, with demands for local control of population levels - the Great Linford population is typical in this respect. The heavy fouling of amenity grassland in country and urban parks is a further cause of complaint . The geese can also cause a deterioration in habitat quality affecting other species by flattening cover which would have been used by nesting birds, such as mallard Anas platyrhynchos.