KEY POINTS:
Unchecked climate change threatens up to 72 per cent of bird species in some areas with extinction, says the WWF conservation group.
But in a report issued yesterday, it says it is not too late to limit the losses.
From migratory insect-eaters to tropical honeycreepers and cold water
penguins, birds are highly sensitive to changing weather conditions and many are being affected badly by global warming, the WWF says.
"Birds are ... already responding to current levels of climate change," said the report, issued at a United Nations conference in Kenya on ways to slow warming.
"Birds now indicate that global warming has set in motion a powerful chain of effects in ecosystems."
An area particularly at risk is the Wet Tropics of north-eastern Australia.*
Climate change was affecting some migratory birds to the extent that they were not migrating.
Unchecked warming could endanger large numbers of species. Estimates of extinction rates were as high as 72 per cent, "depending on the region, climate scenario and potential for birds to shift to new habitats".
But the "more extreme scenarios" of extinction could be prevented if tough climate protection targets were enforced and greenhouse gas emissions cut to keep global warming increases to less than 2C above pre-industrial levels.
Already in decline in Europe and the United States, many migratory birds were missing out on vital food stocks that were appearing earlier and earlier because of global warming, widely blamed by scientists on emissions from burning fossil fuels.
In Canada's northern Hudson Bay, the report said, mosquitoes were hatching and reaching peak numbers earlier in the spring, but seabirds breeding had not adjusted their behaviour.
In the Netherlands, a similar mismatch had led to the decline of up to 90 per cent in some populations of pied flycatchers over the past 20 years.
Predicted rising temperatures could lead to the complete destruction of Europe's Mediterranean coastal wetlands - essential habitats for migratory birds - by 2080.
Rising temperatures were also having disastrous effects on non-migratory species, as their habitats changed.
Many areas rich in birdlife were protected, but climate change could force the birds to move to unprotected places, the report said.
"Island and mountain birds may simply have nowhere to go."
In the United States, unabated warming could cut bird species by nearly a third in the eastern Midwest and Great Lakes, and almost three-quarters of rainforest birds in Australia's northeastern wet tropics were in danger of being wiped out.
The Spanish imperial eagle's entire habitat was threatened.
Also at high risk were eight species of brightly coloured Hawaiian honeycreeper, Galapagos Islands penguins and the Scottish capercaillie - the world's biggest grouse - which WWF said could lose 99 per cent of its habitat because of warming.
- REUTERS
* An earlier version of this Reuters story said the bird species of the whole world were affected. This is not the case.