The Cascades Butterfly Project (CBP) monitors subalpine responses to climate change, with a focus on butterfly populations and plant phenology. The program relies on trained volunteers who conduct weekly surveys throughout the flight and growing season at ten monitoring sites, five each in the North Cascades and Mount Rainier National Park. I complement CBP sampling with annual spatially-extensive surveys in Mount Rainier National Park. My surveys attempt to coincide with peak bloom and butterfly abundances and include subalpine meadows throughout the park. Sampling included 52 meadows, although logistical constraints and weather conditions precluded butterfly surveys at some sites in some years. Over ten years, I detected 42 butterfly species, including all five families known to occur in the Park. Survey data reveal relationships between butterfly abundances, plant distributions, and meadow area. They provide a preliminary glimpse of butterfly population dynamics. For 49 meadows, I compared current subalpine meadow type with Henderson’s (1973) classifications. Most (88%) matched Henderson’s classifications, suggesting persistence under climate change to date. Four have become more lush, likely due to shallower snowpacks and longer growing seasons. Three meadows are transitioning to subalpine forest and likely will cease to function as subalpine butterfly habitat in coming decades.
Dr. John McLaughlin
Western Washington University
Presentation given at North Coast & Cascades Science Days, 2024
go.nps.gov/sciencedays
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