Vinterbeteendet hos gråspetten Picus canus i förhållande till sentida populationstrender i Sverige

Abstract

We recorded habitat use and movement patterns of 2 male and 3 female Grey-headed Woodpeckers with radio telemetry in coastal northern Sweden during the winter 1997/98. Home ranges of females were c. 20 km² large, whereas the home ranges of the males tended to be smaller. Individual birds displayed long movements between day and night locations (maximum 6 km). The woodpeckers showed strong affinity to human settlements (=feeding stations) during daytime. No selection for sites with high abundance of large deciduous trees was found in conjunction with roosting. All radio-equipped woodpeckers disappeared within one-week in early April. Aerial surveys indicated a net displacement of the females of >50 km. Three of the marked woodpeckers (1 male and 2 females) reappeared at their old winter home range in October/November 1998, suggesting a migratory strategy. The findings are discussed in relation to recent population trends and the status of the Grey-headed Woodpecker on the Swedish Red Data list.