The U.K.’s Migratory Bird Population Is Crashing, and Scientists Don’t Know Why
In northern Europe, birds head south for the winter—that’s a given. But a new study shows falling numbers of bird species that spend the winter months in Africa.
Why? That remains a mystery.
Birds migrating to Africa’s humid zone—stretching from southern Senegal to Nigeria—are in the poorest shape, with eight out of the 11 species that visit the region in decline.
Among the species hit the worst are the turtle dove, which has declined by 88 percent since 1995, and the sweet-singing nightingale, whose numbers have dipped 43 percent over the same period of time.
While the study helped identify which birds are struggling the most, researchers have few answers as to the cause of the declines. The study, called the State of the U.K.’s Birds, is an annual review by the Royal Society for the Protection of Birds and seven other environmental groups.
“To understand the changing status of the U.K.’s migratory birds, researchers need to understand more about what’s driving these declines,” the report states.
What they do know is that birds face pressure while wintering in the U.K., during their migratory journey, and over summers spent in sub-Saharan Africa.
In England, birds are experiencing loss of habitat due to increased land development.
“For some species, there is growing evidence of pressure on breeding success here in England,” Alan Law, director of biodiversity at Natural England, said in a statement.
Legal and illegal hunting and trapping could be taking its toll, as birds such as the turtle dove are targeted along their 1,000-plus-mile journey. An estimated two million to four million turtle doves are shot in southern European countries each year.
And in Africa, there’s more trouble. Deforestation to clear land for farms, loss of wetlands due to river damming, and diversion of water for agricultural irrigation has altered the landscape.
The news comes in the wake of an ominous report for the birds of North America, where climate change looks like it could halve the continent’s bird species by the end of the century.
In its seven-year study, the National Audubon Society found that 314 out of the 588 species studied could be affected by a warming world.
And while some birds would actually fare better, the majority would struggle to adapt.