Scottish Greylag Goose Survey
In 1959, an aerial survey of Greylag Geese in Scotland was undertaken in an attempt to assess the size of the breeding population. However, the scale of the task in remote areas and the shy nature of family groups prevented a full assessment being made (Mitchell et al. 2000). Though a few surveys of Greylag Geese in Scotland were undertaken in later years, no real attempt was made to undertake a coordinated census.
In the late 1990s, increased attention being paid to migratory populations of geese in Scotland revealed an apparent gap in knowledge of the status and distribution of the native breeding population of Greylag Geese in the country (Mitchell et al. 2000). A survey of post breeding Greylag Geese in Scotland was thus undertaken in late summer 1997. The survey covered the area to the north and west of Glen Mor between Fort William and Inverness, and west Argyll as far south as the Kintyre peninsula and islands to the west.
Since 1997, the Northwest Scotland and Re-established populations of Greylag Geese increased and the extent to which the two populations overlapped was unknown. In summers 2008 and 2009, surveys were undertaken to try and assess the degree of overlap. The surveys repeated that undertaken in 1997, however, this time the census covered the whole of Scotland.
Aim and methods
The aim of the 1997 survey was to assess the size of the Northwest Scotland Greylag Goose population and identify key sites. The census followed a site based approach and covered all sites known to have suitable habitat.
The aims of the 2008-2009 survey were:
- to assess population size and distribution, and habitats used;
- to examine the extent to which the Northwest Scotland and Re-established populations overlapped;
- to estimate age ratios in the post-breeding population, across the breeding range.
The censuses involved two counts each year: one in July (during moult) and one in August (post moult). A stratified sampling approach was used to identify sites in July, whilst a site based approach was taken in August which provided a total count from certain key areas, such as the Uists.
Results from the Scottish Greylag Goose Surveys can be downloaded from our ‘Reports and newsletter‘ page.
Mitchell, C, D Patterson, P Boyer, P Cunningham, R MacDonald, E Meek, JD Okill & F Symonds. 2000. The summer status and distribution of Greylag Geese in north and west Scotland. Scottish Birds 21: 69-77.