Possible Link between Global Warming and Butterfly Migration

August 24, 2012

Harvard study shows butterfly migration might be caused by global warmingGlobal warming continues to make headlines, and this time it could be a huge factor regarding butterfly populations. A new study shows butterfly species are migrating due to uncertain climate.

Harvard University scientists have revealed in a study, and a published article in Nature Climate Change, that there is likely a direct link between butterfly migration and global warming.

“Over the past 19 years, a warming climate has been reshaping Massachusetts butterfly communities,” Greg Breed, lead author for the study and a postdoctoral fellow at the Harvard Forest in Petersham, said.

Butterfly communities are being reshaped in Massachusetts, because of uncertain climate. For example, the giant swallowtail and zabulon skipper have increased greatly in the state. These are both subtropical and warm-climate species. In addition, more than three-quarters of butterfly species most common north of Boston are on a decline, and rapidly.

“For most butterfly species, climate change seems to be a stronger change-agent than habitat loss,” Breed said. “Protecting habitat remains a key management strategy, and that may help some butterfly species. However, for many others, habitat protection will not mitigate the impacts of warming.”

Habitat protection might be the key to saving species, as the frosted elfin butterfly receives formal habitat protection in Massachusetts and has quickly increased in the area by at least 1,000 percent since 1992.

The Massachusetts Butterfly Club can be thanked for these results. For the past 19 years, the amateur naturalist group has study and logged species counts on about 20,000 outings throughout the New England state. Groups like this one are becoming more and more valuable to scientists.

“Careful datasets from amateur naturalists play a valuable role in our understanding of species dynamics. Scientists constantly ask questions, but sometimes the data just isn’t there to provide the answers, and we can’t go back in time to collect it. This study would not have been possible without the dedication and knowledge of the data collectors on those 19,000 club trips,” Elizabeth Crone, Harvard Forest’s senior ecologist and co-author to the study, said.

-Allyson Koerner

Photo Credit: Wikimedia Commons/Richard Bartz