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We estimated that there were over 3.000 Barnacle Geese at Ballyconnell, it was a hell of a spectacle to see them all come in to land in the late afternoon for a few hours of grazing. When they had landed, we noticed, in among them, there appeared to be a Leucistic Barnacle Goose; that is a goose that is almost totally an albino.Leucism in Barnacle Geese is rare and is caused by a mutation in a single gene. In Scotland’s Solway Firth, with over 11, 000 Barnacle Geese over-wintering, only 12 Leucistic Barnacle Geese have been reported in the last 21 years. Given that the median life expectancy of a Barnacle Goose is about 9 years, then about 1 bird in every 2, 100 would be leucistic (11000 x 21 / 12 / 9 = 2140). In Scotland, the median lifespan of leucistic birds is 2–3 years; this is because they are sought out by (illegal) hunters. These figures refer to birds that breed in Svalbard and Siberia however ours breed in Greenland and may have an entirely different rate of Leucism.(MC)
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