Abstract

The results of the monitoring of woodpecker abundance on the island of Aasla (Finnish Baltic coast) during 1979-1995 are presented and analysed. Population fluctuations on Aasla were similar to those in mainland Finland in the case of the Grey-headed Woodpecker Picus canus and the Black Woodpecker Dryocopus martius. Breeding abundance of Black Woodpeckers was negatively correlated with snow depth and positively correlated with temperature in February. Also, breeding densities of Great Spotted Woodpecker Dendrocopos major and Lesser Spotted Woodpecker Dendrocopos minor correlated positively with mean January and February temperatures. We suggest that several mild winters in the second part of the study period (1988-1995), are the primary reasons for the continuously high population densities of Grey-headed and Black Woodpeckers. We did not find any evidence indicating competition between Grey-headed and Black Woodpeckers. We stress the need for creating foraging substrates (e.g. standing dead wood) as food sources for woodpecker species in boreal forests under severe winter conditions.

Published in

Ornis Fennica
1996, Volume: 73, number: 4, pages: 168-178

SLU Authors

• Mikusinski, Grzegorz

  • Department of Wildlife Ecology, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Zoology


Permanent link to this page (URI)

https://res.slu.se/id/publ/97867