Population trends and fluctuations in Swedish woodpeckers

Abstract

From 1975-1991 there were no population trends in the great spotted Dendrocopos major and black woodpeckers Dryocopus martius but decreases in the green and lesser spotted woodpeckers. The mean annual decrease was about 2% in the green Picus viridis and 4% in the lesser spotted woodpecker Dendrocopos minor. There was no trend in winter weather, and only for black woodpecker were there associations between mild winters and numbers recorded. The great spotted woodpecker population increased in years with a high spruce seed supply. -from Authors