Biodiversity is of great importance for the stability of ecosystems and the balance in nature, and various indicators are used to assess its state. One of these indicators is the Woodland Bird Index (WBI), which measures the population trends of birds in wooded areas and is also a good indicator of overall biodiversity. Austria's forests are one of the most important habitats for native birds; approximately half of all Austrian breeding bird species are influenced in some way by developments in forest habitats. The WBI has proven itself as an indicator for biodiversity in Austria in recent years and is also intended to serve as an indicator in the future based on the Austrian Biodiversity Strategy.
Fig. 1: Jay. Photo: Hans-Jörg Hellwig, 01-veic-07-001, CC BY-SA 3.0
However, the current situation of the WBI has some issues that limit its usability or significance. These shortcomings are to be addressed and corrected with this project. In order to depict a trend of the WBI, it should be calculated for the period 1998–2023. The selection of indicator species as well as the representativeness of data collection will be evaluated. Furthermore, the climate sensitivity of the indicator species will be analyzed and provided in a matrix. This will subsequently serve as a helpful tool for assessing the connections in the context of climate change.
Quite high participation
Fig.2: Wood warbler. Photo: Steve Garvie from Dunfermline, Fife, Scotland, Flickr - Rainbirder - Wood Warbler (Phylloscopus sibilatrix), CC BY-SA 2.0
As part of the project, we checked the data of the indicator species. The number of volunteer counters for BirdLife's breeding bird monitoring has increased significantly in recent years. Every year, an average of 225 people collect standardized observation data, from which we derive population trends. However, for some of the WBI's key indicator species, such as woodcock, black stork and three-toed woodpecker, there is still a lack of annually updated population information.
A targeted evaluation of the observations on www.ornitho.at could provide a remedy, but requires a separate project.
We also examined the representativeness of our monitoring counts. To do this, we used various data sets from the Federal Forest Research Center (BFW), for example on altitude, forest map, timber stock or the distribution of deciduous and coniferous forest. The results show that breeding bird monitoring does not adequately cover coniferous forests at higher altitudes in the central Alps in particular. For an optimal WBI, we should carry out more counts in these regions. At the same time, we have started a study on the climate sensitivity of the indicator species.
This project is funded by the Biodiversity Fund of the Federal Ministry for Climate Protection, Environment, Energy, Mobility, Innovation, and Technology. BirdLife Austria is the project leader and BFW is a project partner.
