Butterflies Suffering From Changing Climate

Well, this is sad news. Expanding forests in the Canadian Rocky Mountains are slowly isolating groups of alpine butterflies from each other. A new study from the University of Alberta suggests this isolation may lead to the extinction of some species. Global warming is raising the altitude of treeline, and this problem is exacerbated by a policy not to initiate prescribed burns for forest management. Consequently, meadow-loving butterflies, such as the Apollo, are suffering, as forests encroach on mountain meadows. "The risk of local extinction and inbreeding depression will increase as meadows shrink, the population sizes decrease and the populations become more isolated," said Jens Roland, lead author. "The gene pool of this species is getting more and more fragmented, and gene flow is reduced, which means these populations are more vulnerable." One particularly cold winter or summer season may be enough to wipe out an entire meadow of Apollo. The paper appears in today's Proceedings of the National Academy of Sciences. JULIA WHITTY