Posted: Apr 20, 2010 3:24 pm
If it isn't one thing, it's another ...

Is this the end of migration?

Climate change is affecting bird behaviour at a staggering rate. Some 20 billion have already changed their flight plans

By Alasdair Fotheringham in Linares, Spain
Sunday, 18 April 2010 ... 47724.html

It's rained three times as much as usual this winter in Andalusia, and almost every day unemployed amateur ornithologist Javier Caracuel has walked past a disused mining tower in the decaying industrial town of Linares and looked up, expecting the pair of white storks that nest there to have migrated south.
Yet despite the surrounding high noise levels – the tower, some 10 metres high, is jammed between a school and a street clogged with traffic – and Andalusia's wettest winter in decades, the storks have stayed put. And they're not alone. "There have always been a couple of storks at the top of the church spire down by the railway station, but I've never seen so many across town," Mr Caracuel explains, "and there are dozens more in the villages."
The changes in storks' behaviour that Mr Caracuel has observed in one near-forgotten mining town in north-eastern Andalusia are far from uncommon. At a recent high-level congress attended by 200 migration experts, leading Spanish ornithologist Miguel Ferrer estimated that 20 billion birds have changed their migrating habits in the last few decades. The biggest single identifiable reason behind such a massive behavioural shift, involving 70 per cent of the world's migrating birds is – surprise, surprise – climate change.

"Long-distance migrators are travelling shorter distances, shorter-distance migrators are becoming sedentary," says Mr Ferrer, who works for Spain's Higher Council for Scientific Research (CSIC) in the Doñana National Park, one of the key European "stopovers" in bird migration routes. "That has a knock-on effect on almost everything they do, from breeding habits to feeding habits to their genetic diversity, which in turn affects other organisms in their food chain. It's a huge behavioural change, forced on them by rising temperatures."
"Climate change and environmental change are simultaneously forcing migratory birds to adapt extremely quickly," says Ian Newton, a Royal Society member and lifelong researcher into the subject. But if the adaption process is necessarily far faster than the last comparable geophysical phenomenon, the Ice Age, this time round it may not be anywhere near as successful.

Edit: I had to snip parts of the article because of copyright issues. - Mazille