Wood Warbler

The recovery project for the Wood Warbler attempts to apply knowledge gained in a study on the species’ habitat needs to forest management measures in order to create suitable habitats for the Wood Warbler.

Aims

• Direct recovery measures through habitat improvement
  Uninhabited woodland areas that are suitable in terms of location and structure are to be turned into attractive habitats for the Wood Warbler by means of targeted forest management interventions.
• Indirect recovery measures through applying research results to forest management
  The results of recent studies on the habitat needs of the Wood Warbler are to be integrated into forest management practices in order to
  • examine how the findings can inform the practical work of forest management in general.
  • investigate whether management interventions in support of the Wood Warbler are compatible with established commercial forestry practices.

Approach

Together with foresters we selected suitable woodland areas in the Cantons of Basel-Landschaft and Solothurn to implement targeted forest management measures for the conservation of the Wood Warbler. Twenty middle-aged, 1-hectare-large areas dominated by deciduous trees and characterized by an almost closed canopy and dense underbrush were chosen. During the winter months, when the Wood Warblers have migrated to Africa, saplings, shrubs and bushes will be removed in 10 of these areas to clear the forest floor and understory without affecting the tree layer. This creates a type of habitat favoured by the Wood Warbler, characterised by a largely closed canopy and open trunk space between the ground and the lower canopy. The remaining 10 areas will receive no management and serve as controls.

In the next few years, no other forest management measures will be implemented in the prepared areas so that their suitability as habitats for the Wood Warbler can be investigated over a longer period. This also accounts for the possibility that the Warblers may not populate the areas in the spring immediately following the intervention, but later, when the grass and herb layers the species also needs have grown.

In spring 2016, the forest structure and the occurrence of the Wood Warbler and selected breeding bird species were surveyed in all 20 areas. The breeding bird survey serves to evaluate the effects of the forestry measures on other bird species. Bird and forest structure mappings will be repeated in the spring after the interventions and in the years that follow.

Significance

The Wood Warbler was added to the Red List of breeding birds (category “vulnerable”) and thus belongs to the threatened species in Switzerland. It is also one of 50 species in the Swiss species recovery programme run by the Swiss Ornithological Institute and SVS/BirdLife Switzerland, with support from the Federal Office for the Environment (FOEN). The project examines whether protection for the species in its breeding sites can be improved, and how.

Project management

Gilberto Pasinelli, Alex Grendelmeier

Partners

Martin Roth, Head forester Dorneck-Thierstein
Gerhard Walser, District forester Thierstein West / Laufental
Josef Borer, District forester Thierstein Mitte
Christoph Gubler, District forester Dorneckberg-Süd
André Minnig, District forester Hohwacht
Markus Schmidlin, District forester Unteres Laufental

Financial support

Walder-Bachmann-Stiftung
Zigerli-Hegi-Stiftung

Publications