Britain’s birds are being driven northwards to extinction at an accelerating rate because of global warming.
Scientists have calculated that the average range of British birds will move 550 kilometres (340 miles) to the north by 2100 as the climate heats up.
Birds with ranges in Scotland or in mountain regions will be wiped out - such as the snow bunting, which today survives only on the Cairngorm plateau. The Scottish crossbill, the only bird species unique to the British Isles, is also likely to perish.
At the same time, many populations based in south England will thrive as foreign species will take over more and more of the countryside. Already continental birds such as the hoopoe and the serin are poised to cross the Channel, ornithologists have warned.
“We are already seeing significant changes to British birdlife and these are only going to accelerate,” said Dr Steve Willis of Durham University.
In a study to be published on Wednesday in the journal Public Library of Science, researchers will reveal they have found detailed evidence to show a significant wildlife transformation is under way.
The report, by Durham University and the Royal Society for the Protection of Birds (RSPB), outlines changes that have already occurred in the past two decades in response to the 0.6C rise that has affected the nation.
Two particular birds provide telling evidence of the future facing the British countryside and its inhabitants: the lapwing and the cirl bunting, a relative of the yellowhammer. The cirl bunting is common around the Mediterranean, although its range has steadily moved northwards until, late last century, a breeding colony was established in the south of England. By 1989 there were 118 breeding pairs. Today the population has spread and there are now more than 700 pairs. By the end of this century, cirl bunting are likely to be found throughout most of England and Ireland.
By contrast, the lapwing - one of the most characteristic British farmland birds of the 19th and 20th centuries - has suffered devastating drops in population because of changes in agriculture, in particular the introduction of winter-sowing of crops. Now global warming is adding to these effects, with the result that the lapwing has already suffered a 47% reduction in numbers and seems destined to earn itself the status of an endangered species in Britain.
However, it is the very north of Britain that faces the most worrying changes. Apart from the Scottish crossbill and the snow bunting, the Arctic skua, Leach’s petrel and the common scooter also face extinction by the end of the century.
“There is simply no place left for these birds to go,” said Graham Madge of the RSPB. “The crossbill is now confined to the very north of Scotland. As Europe heats up, only Iceland offers the prospect of a new homeland. However, the crossbill cannot fly that far - certainly not enough across the North Sea. Similarly, the snow bunting has had to move further and further up the Cairngorms as the climate has warmed. Basically it is running out of mountain.”
In a separate study published last week, Dr Willis also studied the impact of global warming on insect life and in particular on butterflies. His research showed that species cannot migrate fast enough to keep up with global warming. “The nation’s temperature gradient is moving northwards at a rate of about 4km a year, while the butterflies are only capable of moving range at about 1km a year,” said Dr Willis. “This implies that birds - which feed on insects - could face serious problems in finding food as they move north.”
Other losers will be the red-neck phalarope and the snipe, both wetland birds that are are unlikely to fare well in the coming decades. By contrast, the bizarrely feathered hoopoe, a south European interloper which has now reached northern France, as well as the Dartford warbler, currently confined to a small area of southern England, are both expected to thrive.
“In the past, climate change has affected wildlife in these islands,” added Dr Willis. “However, species have adapted because these changes were relatively gradual. But what is happening now is so rapid, birds simply cannot adapt, and so face extinction.”
Robin McKie, science editor
* From The Observer, Sunday 1 March 2009, and the Guardian:
http://www.guardian.co.uk/environme...
Climate ’hitting Europe’s birds’
Climate change is already having an impact on European bird species, according to British scientists.
Details of the study by an international team of researchers have been published in the journal Plos One.
Some birds are expected to do well as temperatures rise, but these are in the minority, the researchers write.
“Overall, the trend is towards net loss,” said a spokesman for the Royal Society for the Protection of Birds (RSPB), which contributed to the study.
Strong Link
The researchers found birds that are expected to do well as temperatures rise had indeed increased in number since the 1980s.
But some 75% of species studied by the researchers had declined in the same period.
The study compared the change in population numbers of bird species over the last two decades with the projected change in their ranges and found a strong link.
These shifts in species territory are thought to be associated with climate change.
Of the 122 species included in the study (out of 526 species that nest in Europe), 30 are projected to increase their range, while the remaining 92 species are anticipated to experience a contraction in their territory.
Rising temperatures
The latter group includes the lapwing, currently found throughout the UK as well as much of western Europe. That however, is predicted to change with the Lapwing disappearing from areas of southern Europe as temperatures change.
The scientists developed a measure, which they call the climate change indicator, to describe how changes in temperature are affecting species.
Rising temperatures are likely to have a positive effect on some species, said co-author Dr Stephen Willis, from Durham University. This means some birds are likely to extend their ranges north.
That means some mainland species could colonise the British Isles if they continue to respond to climatic warming in the way the models predict, and in the absence of other barriers such as the ability to disperse and the lack of suitable habitat.
Extinction
The Cirl bunting, for example, already has a small presence in the UK, in the south west but as the map above shows, is projected to spread much further across the country.
These potential colonists include the great reed warbler, the subalpine warbler and the bee-eater.
One UK species, the Scottish crossbill, could face extinction, the RSPB warned. The crossbill’s range is already restricted to the Caledonian pine forests of Scotland.
“We need to redouble our efforts,” said the RSPB spokesman, “for a G8 nation to lose a species is shameful.”
The spokesman said preserving pine forests could be crucial to the survival of the crossbill.
The study was the work of researchers from Durham University, Cambridge University, the RSPB, the European Bird Census Council, the Czech Society for Ornithology, the French National Museum of Natural History and Statistics Netherlands.
* From the BBC News, Wednesday, 4 March 2009:
http://news.bbc.co.uk/2/hi/science/...