Population trends and fluctuations in Swedish woodpeckers

This is a quantitative study of population changes in four nonmigratory woodpeckers in Sweden. Data were collected during five periods from late autumn to spring and during the breeding season, mainly using point counts. Most analyses are based on the proportion of the routes (each with 20 points) with observation of the species in each year. From 1975 to 1991 there were no population trends in the Great Spotted and Black Woodpeckers, but decreases in the Green and Lesser Spotted Woodpeckers. The mean annual decrease was about 2 % in the Green and 4 % in the Lesser Spotted Woodpecker. There was no trend in winter weather over this period, and only for the B lack Woodpecker we found associations between mild winters