Europe

Science

Bird's-Eye View of Nature

In the past 20 years, the number of birds in the agricultural areas of Europe has declined drastically. The farmland bird population has decreased by almost 30 percent since 1980. Intensive agricultural management is mainly to blame. Woodland birds are holding their own—their numbers have remained more or less stable. These are the first results of the Pan-European Common Bird Monitoring project, which evaluated the data this year from the bird census of 18 European countries, including the Czech Republic.

Ornithologists throughout Europe evaluated the results of the census of 24 woodland bird species and 24 farmland bird species. On the basis of the populations of common birds, ornithologists want to demonstrate the state of the environment and the variety of life in general. In this way, BirdLife Inter-national and the European Bird Census Council have generated the first-ever pan-European indicator of biodiversity. The project, funded by Britain’s Royal Society for the Protection of Birds, is coordinated by the Czech Society
for Ornithology.

Ornithologists in the field have been reporting alarming data on the decline in population of some bird species for many years; such data have also been supported by many professional studies. Initially, attention was devoted to rare species and to those that were most endangered. It was then discovered that even many birds that were previously very common and plentiful were slowly disappearing from our landscape. For example, between 1969 and 1995 in Great Britain, the number of common partridges declined by 70 percent, the number of skylarks by 60 percent, and the number of starlings by 40 percent. In the Czech Republic, the sharpest decline was among the population of northern lapwings, to almost a 10th of the original number.

When Mao Zedong announced his campaign in China in the 1950s to eradicate tree sparrows as agricultural “pests,” about 9 million such birds were killed. Yet this campaign had no effect whatsoever on the tree sparrow population. But more than 80 percent of tree sparrows in Great Britain disappeared without anyone killing a single bird. Wrynecks and red-backed shrikes have become extinct in Britain.

Today, 195 species of European birds need to be protected, as their numbers have been declining significantly. Of these bird species, 116 inhabit the farmland that covers 50 percent of Western Europe (forests cover 30 percent of Western European soil). Bird populations bound to other habitats have not been diminishing so markedly.

The biggest foe of birds in Europe, especially in the advanced Western countries, is not a dictator but unrelenting agriculture. Mass use of fertilizers, better seeds, pesticides, and mechanization have increased and unified the agricultural cycles. As a result, birds have less food (there are fewer insects and seeds from weeds), and their living and nesting habitats have become smaller (natural preserves for animals and uncultivated land have disappeared; crops are harvested in rapid succession; and birds have nowhere to move).

Moreover, heavy machinery directly kills birds and destroys their nests. So far, even in Europe, the rising clamor for nature conservation has not been able to reverse the devastating impact of agricultural intensification, and programs supporting nature-friendly farming have not become strong enough to change anything significantly.

These are the reasons why European ornithologists have decided to monitor numbers of both the strictly protected and most-endangered species, on the one hand, and rather “common” birds, on the other (e.g., barn swallows, skylarks, starlings, linnets, goldfinches, tree sparrows, lapwings, red-backed shrikes, jackdaws, and other agricultural bird species). Of the woodland species, they are studying chaffinches, great tits, blackbirds, robins, jays, tree pipits, and others.

Why were birds, in particular, chosen to represent the entire animal kingdom as indicators of changes in biodiversity? “Birds live everywhere—in farmland and meadows, in forests, and in cities. In addition, they are sensitive to changes in the environment. So, their decline often reflects changes in numbers of other, less visible and audible animals, and also of plants,” explains Petr Vorisek of the Czech Society for Ornithology, who coordinates the Pan-European Common Bird Monitoring project. There are two additional reasons: Large numbers of enthusiastic amateur ornithologists collect data on the numbers of birds in the field, which is then collectively processed using mathematical models, and the public’s overall fondness and interest in birds.

In 2001, at the Gothenburg Summit, the European Union (E.U.) agreed to halt the decline in biodiversity in member states by 2010. But how should it be measured? How does one monitor whether things are changing for the better? “Our numbers should help to do just that,” says Vorisek. Monitoring is to be repeated again in a year. Scientists intend to compare trends in E.U. member states and in the accession countries. (So far, Slovakia and the states of the former Soviet Union have not participated in the project.)

Naturally, the situation is not the same throughout Europe. For example, the impact of intensive Czech agriculture on birds cannot be compared with the situation in Western Europe. “Our agricultural policy was not any more thoughtful,” Vorisek emphasizes. “But it used outdated technology—in this case to the advantage of birds.”

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