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January 17, 2012

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European birds seen falling behind in race to adapt to warmer world

Jan. 17, 2012
Courtesy of Lund University
and World Science staff

Eu­rope’s birds are fall­ing be­hind in the race to adapt to a warm­ing world, sci­en­tists say.

The cli­mate in Eu­rope has been get­ting warm­er, as it has glob­al­ly. So birds and but­ter­flies that thrive in cool tem­per­a­tures must grad­u­ally move north just to keep their sur­round­ings at the same tem­per­a­tures the ani­mals are used to. This would have en­tailed a move­ment to­tal­ing about 250 km (155 miles) for the past two dec­ades, re­search­ers cal­cu­late.

But birds and but­ter­flies haven’t moved at the same rate, ac­cord­ing to sci­en­tists. Åke Lind­ström of Lund Uni­vers­ity in Swe­den and col­leagues found that but­ter­flies have moved on av­er­age about 114 km north, but birds only 37 km. “Both but­ter­flies and birds re­spond to cli­mate change, but not fast enough to keep up with an in­creas­ingly warm cli­mate. We don’t know what the long-term ec­o­log­i­cal ef­fects of this will be,” said Lind­ström.

But­ter­flies probably adapt faster to cli­mate change be­cause of their shorter life­span, he added. This means genera­t­ions turn over faster, so the gene pool can change more quick­ly. 

“A wor­ry­ing as­pect of this is if birds fall out of step with but­ter­flies, be­cause cater­pil­lars and in­sects in gen­er­al rep­re­sent an im­por­tant source of food for many birds,” he added.

“Over the past 50 years the main fac­tors af­fect­ing bird and but­terfly num­bers and dis­tri­bu­tion have been ag­ri­cul­ture, for­est­ry and ur­ba­nisa­t­ion. Cli­mate change is now emerg­ing as an in­creas­ingly im­por­tant fac­tor in the de­vel­op­ment of bio­divers­ity,” said Lind­ström. “For Swe­den, this will probably mean more spe­cies of bird in the long run; many new spe­cies are al­ready ar­riv­ing from the con­ti­nen­t.”

The study is pub­lished in the re­search jour­nal Na­ture Cli­mate Change.

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Europe’s birds are falling behind in the race to adapt to a warming world, scientists say. The climate in Europe has been getting warmer, as it has globally. So birds and butterflies that thrive in cool temperatures must gradually move north just to keep their surroundings at the same temperatures they’re used to. This would have entailed a movement totaling about 250 km (155 miles) for the past two decades, researchers calculate. But birds and butterflies haven’t moved at the same rate, according to scientists. Åke Lindström of Lund University in Sweden and colleagues found that butterflies have moved on average about 114 km north, but birds only 37 km. “Both butterflies and birds respond to climate change, but not fast enough to keep up with an increasingly warm climate. We don’t know what the long-term ecological effects of this will be,” said Lindström. Butterflies probably adapt faster to climate change because of their shorter lifespan, he added. This means generations turn over faster, so the gene pool can change more quickly. “A worrying aspect of this is if birds fall out of step with butterflies, because caterpillars and insects in general represent an important source of food for many birds,” he added. Sweden shows the strongest trends with regard to birds; however, there is no corresponding Swedish data for butterflies. For the study, the birds have been divided into “cold” and “warm” species, i.e. birds that thrive in slightly cooler or warmer temperatures. “Over the past 50 years the main factors affecting bird and butterfly numbers and distribution have been agriculture, forestry and urbanisation. Climate change is now emerging as an increasingly important factor in the development of biodiversity,” said Lindström. “For Sweden, this will probably mean more species of bird in the long run; many new species are already arriving from the continent.” The study is published in the research journal Nature Climate Change.