LONDON — The song of the skylark and the hovering kestrel about to swoop on its prey could soon become rarities in Europe because of ever more intensive agriculture.
The first-ever comprehensive review of European bird populations says that many common species are rapidly declining in number because of increased pesticide and fertilizer use, draining of marshland, and other changes to their habitats.
``The way we manage land in Europe needs drastic modification if we are to maintain bird populations,'' says Graham Tucker, joint author of the report.
Melanie Heath, the other author, says declining bird populations could be a sign of deeper malaise in Europe's environment. ``Birds are known as excellent environmental indicators, and their decline is a reflection of the degradation and problems facing the whole natural world in Europe,'' she says.
The report, which took four years to compile, is based on 50,000 records from 39 countries covering all of Europe except for areas of former Yugoslavia and the Caucasus.
Of the 514 species found regularly in Europe, 278 were found to be Species of European Conservation Concern, requiring coordinated action to conserve their habitats.
Not surprisingly perhaps, given its size, European Russia has the largest number of birds on the critical list - 133, followed by Turkey (112) and Spain (106).
The survey attributes 42 percent of the decline in bird species to agricultural intensification. Other birds are under threat from excessive hunting, it says.
The threats from agriculture include irrigation of dry grassland, especially in Spain, where heavy use of fertilizers and pesticides along with irrigation pose a severe threat to dry grassland species like the stone curlew and the great bustard.
The converse of irrigation, draining of wet grassland in northwest Europe, also threatens many birds, including the quail (Europe's only migratory game bird), the corncrake, and the barn owl, according to the report.
The barn-owl population, although the most widely distributed land bird in the world, has fallen by more than 50 percent in seven European countries and a further 20 to 50 percent in 13 more.