Farming and French huntsmen take toll of thrush

NICHOLAS SCHOON

Environment Correspondent

The song thrush is one of Britain's most common birds, with well over a million breeding in the country. So why is it on a list of 116 plant and animal species for which the Government and conservation groups have jointly proposed rescue plans?

Because it is in rapid decline and is also one of the best-loved really common birds, with its handsome colouration and attractive, elaborate song. It is quite usual for a song thrush to have more than 100 different song phrases. Over the past 20 years its numbers in woodland areas have fallen by half, and by almost three-quarters in farmland.

There is no shortage of hypotheses for why this should be, but not much in the way of established facts. Huge changes in farming are implicated. The wholesale switch from spring to autumn sowing of cereal crops may have deprived the song thrush of an important food source in spring, when the ploughing brought the small, invertebrate animals it eats to the surface.

Growing use of molluscicides - pesticides which kill slugs and snails - may have curbed its food supply. The shrinking length of hedgerows may have reduced nesting and feeding areas. Some thrushes migrate from France to Britain to breed, and it may be that French huntsmen are shooting large numbers of these. Magpies, foxes and cats may be eating the song thrushes' eggs and chicks in the nest.

The rescue plan, drawn up by a committee of civil servants, government wildlife scientists, conservation groups and landowning interests, has the objective of halting the decline in song thrush numbers by 2000.

But it is vague about how this can be achieved because the causes are not fully understood. One proposal is to press for the European Union to ban French hunters shooting them.

The plan says that much research is needed into how the bird feeds, moves around and rears its young.

The Royal Society for the Protection of Birds is carrying out a detailed three-year study, looking at one area in West Sussex where the bird is holding its own and another in Essex where there has been a marked decline. The cost of the rescue plan, including this research, is put at up to pounds 124,000 a year.