Calculating the predictability of climate change: the effect of climate change on moth species in the Pacific Northwest varies…

Climate change has driven shifts in phenology and distribution for many species. These effects are often idiosyncratic and it remains unclear whether they vary consistently among functional groups, limiting our ability to draw broad conclusions about how climate change affects species. Previous studies have indicated that Lepidoptera (butterflies and moths) are sensitive to climate change. We analyzed a large database of moth specimen records from the Pacific Northwest (PNW) to examine climate change responses over more than 100 years for a suite of 241 functionally diverse species, including spring and fall active species as well as dietary generalists and specialists. Our goal was to investigate the effect of among-year variation in regional late winter to early spring temperatures on the seasonal timing of adult activity, and whether that effect differs among moth functional groups. We hypothesized that moths would have earlier flight dates in warmer years, and that this effect would be greatest for both early-season and dietary specialists.