Severe droughts resulting from ongoing climate change could put many species of butterflies in the United Kingdom as risk of extinction, researchers say.
Some species especially sensitive to the effects of global warming could be extinct by 2050 even at the lowest expected levels of warming, they warn.
Six species of butterflies found to be particularly sensitive to drought could be lost from several areas of the country by midcentury, they predict in a study published in the journal Nature Climate Change.
They based that prediction on a study of how butterflies fared in 1995, the driest summer since record keeping began in 1776. Similar droughts are expected to become more frequent in the future with climate change, the researchers say.
"On average across the whole country it is quite bleak," say study lead author Tom Oliver at the UK Center for Ecology and Hydrology. "I was surprised looking at climate data by the rapid increase in frequency of droughts we are in for."
Historically the drought of 1995 was a once-in-200-years event, but with ongoing climate change it could be happening every 7 years by 2050, he says.
The six species highlighted in the study as particularly sensitive to drought effects were the cabbage white, the small cabbage white, ringlet, the green-veined white, the speckled wood and the large skipper.
And butterflies aren't the only creatures at risk from drought, Oliver says.
"It's likely other species besides butterflies will be affected by drought," he says. "Because butterflies are a well-studied group they can be used as an indicator for other groups, a canary in the coal mine, if you will."
The worst impacts of climate change could be lessened by efforts to restore connections between butterfly habitats fragmented by human activities such as agriculture, the researchers say.
Reconnecting fragmented habitats could increase the odds of butterfly survival by 50 percent, the researchers suggest.
"If our habitats are very fragmented, the impacts will be much more severe," Olive says. "In places where it isn't [fragmented], those populations might persist."
For the study, data from 129 habitats for 28 species monitored as part of the U.K. Butterfly Monitoring Scheme was combined with historic climate data and computer model projections of climate change.
"There's good news and bad news here," says study co-author Mike Morecroft of Natural England. " The good news is that we can increase the resilience of species to climate change by improving our natural environment, particularly increasing areas of habitat, and we are working hard at this."
However, he notes, such an approach can only succeed if climate change is kept in check by effective controlling of greenhouse gas emissions.
