Anvils of the Great Spotted Woodpecker (Dendrocopos major) in primeval oak-lime-hornbeam stands of the Białowieża National Park

Abstract

The seeds of Norway spruce (Picea abies) are important food for the Great Spotted Woodpecker (Dendrocopos major), especially in winter, when other resources are limited. However, little is known about preferences of woodpeckers in terms of the location of anvils, in which seeds of Norway spruce are extracting from cones. In this study, we documented preferences of the Great Spotted Woodpecker for anvil placement sites and checked whether there are differences between males and females in this respect. The research was conducted in primeval oak-lime-hornbeam stands of the Białowieża National Park, E Poland. To determine preferences of woodpeckers regarding the species and condition of trees in terms of the location of anvils in our research we took into consideration available resources of trees. Altogether during our study, we collected data on 358 anvils. They were most often located on large trees, having a much larger trunk diameter than the average diameter of trees from resources. We found the greatest number of anvils on oak (30%), which was also the most preferred tree species by woodpeckers. Anvils were located the most often on branches (72%), on dead parts of trees (67%) and at great heights (on average over 19 m above ground). We found no differences between males and females in the selection of anvil placement sites.