Butterflies heading north
PETERSHAM, Mass. — The authors of a Harvard study published today in Nature Climate Change gathered their data from an unlikely source — the trip accounts of the Massachusetts Butterfly Club. During the past 19 years, the amateur naturalist group has logged species counts on nearly 20,000 expeditions throughout Massachusetts. Their records fill a crucial gap in the scientific record. Once analyzed, the data show a clear trend. “Over the past 19 years, a warming climate has been reshaping Massachusetts butterfly communities,” notes Greg Breed, lead author on the study and a postdoctoral fellow at the Harvard Forest in Petersham. Subtropical and warm-climate species such as the giant swallowtail and zabulon skipper — many of which were rare or absent in Massachusetts as recently as the late 1980s — show the sharpest increases. At the same time, more than three-quarters of northerly species (species with a range centered north of Boston) are...