Modelling the European Farmland Bird Indicator in response to forecast land-use change in Europe

The European Farmland Bird Indicator (EFBI) has been adopted as a Structural and Sustainable Development Indicator by the European Union. It is an aggregated index integrating the population trends of 33 common bird species associated with farmland habitats across 21 countries. We describe a modelling method for predicting this indicator from land-use characteristics. Using yearly historical land-use data of crop areas derived from the FAO databases (1990–2007) and published population data of farmland birds at the national level for the same period, we developed a series of multiple regression models to predict the trend of the EU state specific indicator, and the EFBI. These models incorporated up to 4 parameters and were selected based upon the significance (p < 0.05) of the model inputs with respect to the predictive variable. 17 separate models were developed in total for each of 14 EU countries plus Norway and Switzerland, and a separate model for the EU level indicator. The selected models were then implemented to predict the EFBI in the year 2025, using scenarios of land-use change generated by the CAPRI agricultural model. The uncertainty of using the regression models is discussed with respect to predicting the likely impacts of land-use change on bird populations. This work lays the framework for future modelling of farmland birds at the international scale.