While Southern butterflies are moving north, more than 75 percent of species north of Boston, are rapidly declining, the study found. Species that overwinter as eggs or larvae are disappearing fastest, which suggests warmer winters may be the cause, Whitty reports. "For most butterfly species, climate change seems to be a stronger change agent than habitat loss," lead study author Greg Breed said. Habitat protection is a major step in protecting butterflies, but Breed said that for many species, "Habitat protection will not mitigate the impacts of warming."
The Butterfly Club is a citizen scientist group that for the last 19 years has logged butterfly species and numbers during 20,000 expeditions through Massachusetts. "Their records fill a crucial gap in the scientific record," Whitty reports. "Butterflies are turning out to be the canaries in the coal mine of climate warming." (Read more)