Abundance and distribution of selected species (SEBI 001) - Assessment DRAFT created Nov 2010
Biodiversity (Primary topic)
- SEBI 001
Key policy question: Have declines in common species in Europe been halted?
Overall, Europe's common bird populations reduced by around 10 % since 1980. Common farmland birds declined most severely (around 50 %) but common forest birds also declined by some 5 %. Falls have levelled off since the late 1990s. Europe's grassland butterflies have declined dramatically (almost 70 %) since 1990 and this reduction shows no sign yet of levelling off.
Grassland butterflies — population index (1990 = 100)
Note: How to read the graph: since 1990, grassland butterflies have declined by almost 70 %.
- Conservation of butterflies, moths and dragonflies provided by Dutch Butterfly Conservation
Common birds in Europe — population index (1980 = 100)
Note: How to read the graph: since 1980 the number of common farmland birds has declined by around 50 %
EBCC/RSPB/BirdLife International/Statistics Netherlands, 2009.
For some populations of European common birds, downward trends appear to have slowly levelled off but it needs to be borne in mind that significant losses had already happened by 1990. Of the more common bird species, farmland birds have declined. The initial steep decline of farmland birds was associated with increasing agricultural specialisation and intensity in some areas, and large-scale marginalisation and land abandonment in others. The falling trend has levelled off since the late 1990s, partly because of stabilising inputs of nutrients and pesticides and the introduction of set-aside in the EU-15, and partly because of drastically lower nutrient inputs in the EU-10 as a result of political reforms and the resulting economic crisis in the agricultural sector. An increase in agricultural production in eastern Europe, if linked to higher inputs of nutrients and pesticides, combined with further land abandonment in some parts of Europe and the abolition of set-aside, may lead to a new decline.
Conservation measures adopted under the EU Birds Directive have proven effective in the recovery of threatened bird populations (Donald et al., 2007) but not in the case of more widespread birds species, where different recovery mechanisms are now required. Well-designed agri-environment measures have been shown to reverse bird declines at local levels. The recent loss of set-aside areas under agricultural policy may result in greater pressures on many farmland bird species.
The challenge now is to deploy the Birds Directive conservation measures or others widely enough to help populations recover at national and European scales. Trends in species in Europe are also driven by pressures outside Europe, e.g. for migratory bird species, and a comprehensive response would need to be effective beyond European territory.
Grassland butterflies are declining severely; their populations have declined by almost 70%, indicating a dramatic loss of grassland biodiversity.
The main driver behind the decline of grassland butterflies is the change in rural land use: agricultural intensification where the land is relatively flat and easy to cultivate, abandonment in mountains and wet areas, mainly in Eastern and Southern Europe. Agricultural intensification leads to uniform, almost sterile grasslands, where the management is so intensive that grassland butterflies can only survive in traditional farmed low input systems (High Nature Value Farmland) as well as nature reserves, and marginal land such as road verges and amenity areas.
An increase in the population index means that there are more species with populations increased than species with populations decreased: it does not necessarily mean that the population of all species has increased. It can be due to expansion of some species (typically, generalists) at the expense of other species (typically, specialists). It must also be noted that populations fluctuate on a yearly basis.
In the absence of the information on abundance, information on the distribution of species can help assess species status. However, at a European level, this type of information is still weak for other groups of species.
Trends of common birds in Europe
provided by European Bird Census Council
The European Butterfly Indicator for Grassland species: 1990-2007
provided by Dutch Butterfly Conservation
More information about this indicator
See this indicator specification for more details.