Common birds in Europe — population index (1980 = 100)
For common farmland bird species, n=36; for common forest bird species, n=29; for all common bird species (this line includes the farmland and forest birds as well as other common species that are not primarily associated with either of these habitats), n=136.
Country coverage (i.e. reflecting the availability of high-quality monitoring data from annually-operated common bird monitoring schemes, employing generic survey methods and producing reliable national trends): Austria, Belgium, Bulgaria, Czech Republic, Denmark, Estonia, Finland, France, Germany, Hungary, Ireland, Italy, Latvia, the Netherlands, Norway, Poland, Portugal, Slovakia, Spain, Sweden, Switzerland and the United Kingdom. See www.ebcc.info for more technical information on the calculation of the index.