Balmy winter puts chill on bird migration

CNN/Reuters: Balmy winter puts chill on bird migration
December 20, 2006


Warm weather has delayed the migration of some birds.

OSLO, Norway (Reuters) -- Some European birds have failed to fly south for the winter, apparently lured to stay by weeks of mild weather that experts widely link to global warming.

Birds including robins, thrushes and ducks that would normally fly south from Scandinavia, for instance, have been seen in December -- long after snow usually drives them south. And Siberian swans have been late reaching western Europe.

"With increasing warmth in winter we suspect that some types of birds won't bother to migrate at all," said Grahame Madge, spokesman of the British Royal Society for the Protection of Birds (RSPB).

Many individual birds were leaving later, and flying less far.

One Swiss study this month suggested that Europe has just had the warmest autumn in 500 years. Frosts have crept south in the past week -- chilling any birds gambling that the entire winter will be balmy.

Madge said that Bewick's swans, for instance, which usually arrive in Britain in October from Siberia in Russia had apparently stopped for longer than usual in countries such as Estonia or the Netherlands because of plentiful food....

http://www.cnn.com/2006/TECH/science/12/20/birds.migration.reut/index.html