The Diverse Reactions of Butterflies and Zygaenids (Lepidoptera) to Climate Change—A Large Scale, Multi‐Species Study

Aim An extensive dataset was used to decipher the different responses of 46 species of butterflies and Zygaenids (Lepidoptera) to climate change. The study included more than 1.5 million observations from four databases in Europe, with a south–north extension of about 1200 km from south‐eastern France, via Switzerland and Baden‐Württemberg (Germany) to Brandenburg (Germany). Altitude information was only available for France and Switzerland. Location Europe. Time Period 1894 to 2022. Taxa Studied Lepidoptera, 46 species. Methods Linear models were used to investigate the change over time of the beginning, median, and end of the flight period, as well as the change in altitude. The length of the flight period and the altitudinal range of two time periods were compared. Distribution curves were interpreted with respect to changes in voltinism. Results The beginning and the median of the flight period were increasingly earlier in 100% of the significant changes, while the end of the flight period was later in 69%. Below a mean altitude of about 1000 m, species were more likely to change phenology, while above 1500 m, altitude shift was more likely. In terms of voltinism, 47% of the distribution curves showed no change, 27% a major shift from one generation to another, 20% an additional generation, and 6% a merging of generations. Main Conclusion Four major responses to climate change were identified: no response (6 species in France, 5 in Switzerland), change in phenology (19 in France, 13 in Switzerland), change in altitude (11 in France, 21 in Switzerland) and change in both (2 in France and 7 in Switzerland). This study provides evidence that the response of Lepidoptera to climate change is variable and that these responses differ not only between species but also between regions. Ecological traits are used to discuss these differences in the species considered here.