Decline in Migratory Birds in UK Likely Caused by Land Changes, Group Says

UK scientists say that a steep decline in the number of migratory birds arriving each spring from Africa — including cuckoos, nightingales and turtle doves — is likely the result of land pressures on both ends of the birds’ annual migrations. Since 1995, the number of turtle doves returning to UK woodlands from their African wintering grounds has dropped 71 percent, while the number of nightingales has fallen 53 percent and cuckoos 44 percent, said Danaë Sheehan, a senior conservation scientist with the UK-based Royal Society for the Conservation of Birds (RSCB). While the specific causes are unknown, Sheehan said changing land uses in the UK and the loss of habitat and growing human populations in Africa are likely causes. Also, scientists say many bird species are increasingly losing food sources, such as insects, in their spring nesting grounds as a consequence of climate change. “There are so many different possible causes for these losses, which makes it difficult to tease out the factors involved in their decline and prepare plans to put things right,” she said. To better understand the problem, scientists with the RSCB and the British Trust for Ornithology have launched a series of surveys of bird species in the UK and Africa.