Climate reshapes butterfly ranges worldwide, with expansions outpacing contractions

Global butterfly ranges are shifting widely in response to climate change, with 1,758 species across 105 countries documented in 6,182 range-shift reports. About 80% of species expanded their ranges, and 79% of shifts are linked to climate change and extreme weather; 27% contracted and 22% shifted elevationally, with expansions strongest in the tropics and contractions and elevational shifts more common in Europe and North America. The study stresses biases from uneven data and the value of integrating non-English literature and expert assessments, and urges expanded monitoring, citizen science, and conservation planning that accounts for range dynamics, microrefugia, and habitat connectivity to buffer biodiversity against climate- and land-use change.