Butterfly colony trial hints at novel climate fix

A butterfly settles on a flowering plant in a tropical biomes at the Eden Project in Cornwall, March 17, 2001.

OSLO (Reuters) - An experiment relocating butterfly colonies in Britain shows that animals and plants can be moved to new, cooler habitats to help them survive global warming, scientists said on Wednesday.

"Very many species around the world are moving because of climate change. But they are often moving slowly, lagging behind shifts in the climate," said Chris Thomas, professor of Conservation Biology at the University of York.

Assisted colonization -- moving creatures or plants to a habitat that has become suitable because of global warming -- could help to safeguard wildlife and avert extinctions, he said.

In an experiment, batches of marbled white and small skipper butterflies were caught in north England in 1999 and 2000 and taken up to 65 km (40 miles) north of the northernmost edges of their ranges, to areas identified as suitable by computer climate models.

"Both populations have become established and are thriving," Brian Huntley, a professor of environmental changes at the University of Durham who was among the authors of a study published in the journal Conservation Letters, told Reuters.

Some types of animals and plants were simply unable to move to search out new habitats, the study said. Marbled whites, for instance, like limited habitats such as grass growing on a limestone base.

The scientists said it was the first example of assisted colonization linked to climate change, including assessments in advance to judge if the new arrivals would disrupt the new habitat.

WARMING

Global warming, stoked by emissions of greenhouse gases from burning fossil fuels, is driving many species toward the poles as part of shifts that could disrupt food production.

Thomas said that assisted colonization could be applied anywhere, from Australian tropical forests to coral reefs. It could be costly but cheaper than allowing species to dwindle to numbers where they had to be bred in zoos.

Many scientists favor creation of "green corridors" so that wildlife can migrate if their habitats get too warm and cities, roads or farmland are in the way. Assisted colonization could be a backup, mainly for rare species.

For plants, those with wind-borne seeds such as grasses or dandelions would have few problems, Huntley said. But some plants rely, for instance, on ants to disperse seeds.

"They don't get moved very far -- meters or tens of meters at most," he said. "They will experience considerable difficulty as the climate warms."

He played down suggestions that moving butterflies could disrupt ecosystems by introducing "alien" species.

"Within the European continent animals have moved around a lot in the past as conditions change," he said, adding that introducing a creature from another continent may be more of a threat.

(Editing by Louise Ireland)