How much dead wood is needed for survival of European three-toed woodpecker?

Information on target species obtained so far in the project Life Kočevsko raise new questions and we look for the answers in literature or in the forest which is always the best classroom. After finishing the woodpecker field surveys in the first half of 2015 we invested additional effort into finding nesting holes of white-backed and European three-toed woodpeckers. We found 4 nesting holes of which two in GGE Stojna and GGE Velika gora were occupied by European three-toed woodpeckers.

The location of the nesting holes raised new questions: How large is the home range of each pair? What shape it is? How much of the dead and dying wood and in which phase of decay this species needs for survival?

We carried out a field survey and measured total amount of standing and lying dead wood and the phases of its decay. In an area of 3.2 ha in GGE Velika gora we measured 601 m³ of conifer dead wood (standing and lying). In an area of 2.3 ha in GGE Stojna we recorded 35 m³ of dead and dying trees. We thus obtained a rough estimate of how much dead wood provides enough insect larvae to feed a family of European three-toed woodpeckers. To obtain informatio on the size and shape of home range we would need telemetric data on the movements of adults during the breeding season which exceeds the financial framework of this project.

Similar measurements of dead wood will also be carried out at two known locations of the nesting holes of white-backed woodpeckers if the mild winter weather persists.

News write by: Zavod za gozdove Slovenije, OE Kočevje