Barnacle geese in the west of Scotland, 1957-1967

Abstract

Five aerial surveys of the Barnacle Geese wintering on islands off the west and north-west coasts of Scotland were made between February 1957 and April 1966. The practical problems of the aerial survey of geese dispersed in small groups on islands are discussed. Supplemented by counts made from the ground on Islay, much the most important haunt, the surveys show that the Hebridean population has increased substantially from about 7,400 in February 1957 to 15,200 in April 1966. Numbers in different regions of the Hebrides have varied in rather similar ways. The gradual increase on Islay up to 1966 may have been due to low adult mortality. A massive increase there in 1967 must have involved immigration. The geese in Sutherland, and in Ireland, afforded full protection since 1955 and 1962 respectively, have increased less than in the Hebrides, where shooting is permitted in the months of December and January. The present healthy state of the Hebridean population could be drastically altered if their competition with agriculture on Islay leads to countermeasures.