Habitat-specific bird trends and their effect on the Farmland Bird Index
Farmland birds in Europe have declined in numbers from the last decades, as reflected in the Farmland Bird Index (FBI), a multi-species indicator of population trends adopted by the European Union. Some of these farmland bird species breed to a varying degree also in non-farmland habitats: however, the indicator is calculated using trends estimated from all birds counted of each species, irrespect