Fewer butterflies seen by community scientists across the warming and drying landscapes of the American West

Many recent studies have revealed sweeping declines in insects over the past few decades. Butterflies are no exception. Forister et al. used three different datasets, collected by both experts and community scientists, and found that the number of butterflies has declined over the past 40 years. Although the drivers of decline are complex, the authors found that climate change—in particular, warmer months in the autumn—explain a large portion, even as warming summers actually lead to increases. This work shows that climate change impacts may be insidious and unexpected in their effects.