Demography of Capercaillie Tetrao urogallus in North-East Scotland. II. Age and Sex Distribution

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Abstract
Age and sex distribution of Capercaillie seen and shot in north-east Scotland were used to calculate rates of loss and of mortality. The sample came largely from open, mature forest where densities were high. Although Capercaillie usually rear more female than male chicks, fully-grown cocks outnumbered hens. This could be explained by a net loss, thought to be due largely to emigration, of young hens in their first October. After this initial loss of hens, the calculated loss of young birds between their first and second winters was negligible. It was inferred that yearling cocks tended to emigrate in their second year. The average annual rate of loss of old birds (yearlings and adults combined) was estimated at 45%.