Indicator: Common bird index by type of species
Indicator name

Tag: SDG_15_60
Indicator abbreviated name

Definition: The indicator is a multi-species composite index, which measures the relative abundance of a selection of common bird species associated with specific habitats. Three groups of bird species are represented: common farmland species (39 species), common forest species (34 species) and all common bird species (168 species; including farmland and forest species). The index for each group is calculated at EU level only, using 1990 as reference year.
Definition describing what the indicator measures

Unit: Index measuring changes in population abundances of bird species compared to the reference year 1990 (Index 1990 = 100).
Measurement unit of the indicator values

Spatial coverage: EU (continental territories only; country composition varies by reporting year)
Geographic area covered by the indicator

Temporal coverage: 1990-2024
Time coverage of the indicator from first to most recent available year

Update frequency: Every year
Frequency at which indicator is updated

DPSIR: State
DPSIR classification framework: Driver, Pressure, State, Impact, or Response

Method: 1) Calculation of national indices per species by coordinators of national monitoring schemes; 2) calculation of composite multispecies indices (common farmland birds, common forest birds and all common birds) using Monte Carlo simulations as described in Soldaat et al. (2017) and an R-script (R-TRIM) developed by Statistics Netherlands (2017). No rare species are included, although some species common in certain Member States may be considered rare in others. The species covered under the common farmland and common forest indices are deemed to be dependent on that particular kind of habitat for feeding and nesting. The index of common farmland birds covers 39 species that depend on farmland (farmland specialists). The index of common forest birds covers 34 species that depend on forests (forest specialists). The index of all common birds covers both farmland and forest birds plus 95 other common species that depend on other habitats, including built-up areas, urban parks and gardens (generalist species). The list of species is available on PECBMS website (https://pecbms.info/methods/pecbms-methods/3-multispecies-indicators/species-selection-and-classification/). Each of the three EU bird indices is presented as a smoothed time series with 95% confidence limits. More information can be found in the metadata of the original dataset on the Eurostat website (https://ec.europa.eu/eurostat/cache/metadata/en/env_biodiv_esms.htm).
Description of the main methodological steps used to calculate the indicator

Reference: Sustainable development in the European Union - Monitoring report on progress towards the SDGs in an EU context - 2025 edition (https://ec.europa.eu/eurostat/web/products-flagship-publications/w/KS-01-24-018), accessed 24 February 2026. Gregory, R. D., van Strien, A. J., Vorisek, P., Gmelig Meyling, A. W., Noble, D.G., Foppen, R.P.B. et Gibbons, D.W., 2005, 'Developing indicators for European birds', Philosophical Transactions of the Royal Society B 360, pp. 269-288. Soldaat, L. L., Pannekoek, J., Verweij, R. J. T., van Turnhout, C. A. M. and van Strien, A. J., 2017, 'A Monte Carlo method to account for sampling error in multi-species indicators', Ecological Indicators 81, pp. 340–347. Statistics Netherlands, 2017, Models and statistical methods in rtrim, Statistics Netherlands (https://www.cbs.nl/en-gb/background/2018/49/models-and-statistical-methods-in-rtrim), accessed 24 February 2026.
Reference sources describing the indicator and method to calculate it (e.g. peer-reviewed articles, scientific/technical reports, webpages, other)

Producer: European Bird Census Council (EBCC); National BirdLife organisations; Royal Society for the Protection of Birds (RSPB); Czech Society for Ornithology (CSO)
Institution which produces the calculation of the indicator values

Provider: Eurostat
Institution supplying the indicator values, even if not the original producer of indicator values

Open source: False
Indicates whether calculation code is openly available

Spatial scope (Member States): False
Whether the indicator is available at Member States level

Spatial scope (EU27): True
Whether the indicator is available at EU27 aggregated level

Spatial scope (global): False
Whether the indicator is available at global level

Accuracy uncertainties: Temporal comparability: the entire time series is recalculated using a given model, each year, and the results are compared against the earlier ones by the data providers; however, fewer countries contributed to the data set in the early years of the data collection.
Comment on data accuracy, limitations, and uncertainty

Comments: None
Additional remarks

Storage: None
Webpage link containing the code and/or detailed description of the workflow to calculate the indicator

Copyright/Licence of use: Eurostat copyright notice: https://ec.europa.eu/eurostat/statistics-explained/index.php?title=Copyright/licence_policy.
Copyright or licensing information related to the indicator