|Farmland bird species trends in the EU
The trends of bird species that depend on farmland habitat for breeding are being tracked since 1980 by the Pan-European Common Bird Monitoring Scheme. This indicator for common farmland birds is based on data from 23 EU countries and tracks 37 species. Since 1980 the index dropped with 51%, which means that the population has halved! From the 37 species: 6 increased in number, 6 were stable and for 3 species the trend is uncertain. This means that the great majority, 22 species, have declined in numbers.
Species that increased in numbers are the White Stork (Ciconia ciconia) and the Rook (Corvus frugilegus).
The list of declining farmland birds is long and Grey Partridge (Perdrix perdrix) (-94%) and Ortolan Bunting (Emberiza hortulana) (-87%) showed a steep population decline.
The Grey Partridge is declining mainly because of habitat loss and degradation caused by agricultural intensification and loss of insect food sources on farmland. Especially the Grey Partridge chicks are very vulnerable. They feed on insects, especially caterpillars, beetles, bugs, ants and aphids which they take mainly from crop margins. Breeding is more successful when there is plenty of this food available. The loss of seed sources, loss of nesting habitat and predation have also contributed to the decline.
The Eurasian skylark (Alauda arvensis) has showed a moderate decline in numbers during the last decades but hardly survives as a breeding bird in intensively cultivated farmland.
In the United Kingdom the creation of skylark plots, which are small undrilled patches in winter cereals, have proven to boost nesting success. Two plots per hectare of at least 16m2 each, in fields larger than five hectares can boost productivity of skylarks by almost 50%.
The winter survival of bird species that breed on farmland is getting worse, probably because fewer seed food sources are available to them on farmland. Grey Partridge and Yellowhammers are species of which the adults feed mainly on seeds throughout the year, especially on cereal grain. They seek places where they can find lots of seed food, such as winter stubbles, root crops, wild bird cover, weeds in the crop margin, areas where grain is spilt or where cereals are fed to cattle.
Bird species adapted to wetland habitats like Black-tailed godwit occurred in large numbers in farmland habitat in Northwest-Europe. Numbers of these breeding meadow birds are declining rapidly. Draining leads to the loss of shallow waters in the grassland, less winter flooding and lower groundwater levels. Moreover, as a result of these impacts, mowing is beginning earlier in the year, the use of fertilisers is increasing, and the number of livestock in the fields is falling.
Willem Van den Bossche, Willem.Vandenbossche(at)birdlife.org