There are more winners than losers shown by the new Breeding Birds Survey, published yesterday, but some of the birds not doing well are in serious trouble.
Corn buntings, yellowhammers and linnets, all once familiar birds of the farmer's fields, have suffered serious drops in population over the five years that the survey has been done, as have bullfinches, which are largely birds of orchards. The intensification of agriculture, with its increasing use of weedkillers and insecticides that render fields virtually sterile, is thought to be behind the declines. On the other hand, willow warblers and their cousins the chiffchaffs have shown big increases, as have two more woodland warblers, whitethroats and blackcaps - all birds likely to have been shielded by their woodland habitat from intensive farming's worst effects.
The annual survey, which is conducted jointly by the Royal Society for the Protection of Birds, the British Trust for Ornithology and the Joint Nature Conservation Committee (which represents the Government's wildlife agencies) began in 1994. This year it is displaying its first five-year trend, which shows that 33 species increased over the period 1994-98, and 20 declined.
Some of the increases, such as those in wheatears and redstarts (45 per cent and 42 per cent respectively) may be due to more favourable conditions in their African wintering grounds, said Chris Harbard of the RSPB, while declines in other migrants, such as spotted flycatchers and lesser whitethroats, might be due to problems in their winter homes.
Some birds are increasing because they are spreading: buzzards (up 22 per cent over the period) are moving back into central and eastern England, from which they were driven out by gamekeepers; green woodpeckers are spreading north, perhaps because of global warming.
Information collected by the survey allows a close watch to be kept on about 100 different species of bird from a wide variety of regions and habitats across the United Kingdom.
Its potential importance as an environmental monitoring tool is underlined by the recent government decision to use breeding bird numbers as an indicator of the quality of life.Reuse content