PARENT SESSION
Oral Session #15: Paleoecology and Climate Change.
Presiding: J. Betancourt
Monday, August 5. 1:00 PM to 3:45 PM. Graham Meeting Room, TCC.

Climate change hastens population extinctions.

McLaughlin, John^*,1, Hellmann, Jessica², Boggs, Carol³, Ehrlich, Paul³, ¹ Department of Environmental Sciences, Bellingham, WA² Centre for Biodiversity Research, Vancouver, B.C., CANADA³ Center for Conservation Biology, Stanford, CA

ABSTRACT- Climate change is expected to alter the distribution and abundance of many species. Predictions of climate-induced population extinctions are supported by geographic range shifts that correspond to climatic warming, but few extinctions have been linked mechanistically to climate change. We show that extinctions of two populations of the Bay checkerspot butterfly, Euphydryas editha bayensis, were hastened by increasing variability in precipitation, a phenomenon predicted by global climate models. We model checkerspot populations to show that precipitation changes amplified population fluctuations, leading to rapid extinctions. As populations of checkerspots and other species become further isolated by habitat loss, climate change is likely to cause more extinctions, threatening both species diversity and critical ecosystem services.

KEY WORDS: precipitation variability, population fluctuation, checkerspot butterfly, extinction