Extensive climate-induced range shifts in butterflies across the globe

Shawan Chowdhury , Upama Aich, Laura Antão, Stefan Pinkert, Perpetra Akite, Gilberto SS Almeira, Tatsuya Amano, Andras Ambrus, Jade A.T. Badon, Seung-Yun Baek, Maksims Balalaikins, Michal Barták, Vijay Barve, Michał Bełcik, Timothy C Bonebrake, Simona Bonelli, Diana E. Bowler, Michael F Braby, Roger Cartig, Sei-Woong Choi, Wen-Chen Chu, Eloisa Clain, Steve Collins, Johnattan H Cumplido, Leonardo Dapporto, Gideon Deme Gywa, Matthias Dolek, Aleksandra Dolezal, Fahmi I Firdaus, Markus Franzén, André VL Freitas, Richard Fuller, Luisa Gensch, Eliza M. Grames, Elia Guariento, Bryan Haywood, Shiran Hershcovich, Kerstin Jantke, Eddie John, Henrik kalivoda, Azadeh Karimi, Ryosuke Katayose, Akito Kawahara, Sujan Khanal, Krushnamegh Kunte, Lionel L'Hoste, Magdalena Lenda, Jorge L León-Cortés, Dali Lin, Yuet Fung Ling, Maria Lucia Lorini, Dirk Maes, Dino Martins, Thomas Merckx, Xavier Mestdagh, Yeray Monasterio, Akihiro Nakamura, Rachel Rui Ying Oh, Lars B Pettersson, Jeffrey S Pippen, Clara Pladevall, Ingrid Pollet, Patrice Pottier , Muhammad Ather Rafi, Danielle L Ramos, Tharindu Ranasinghe, Fanie Rautenbach, Martin Reith, Abubakar S Ringim, Federico Riva, David Roy, Nils Ryrholm, Marjo Saastamoinen, Josef Settele, William Sidemo-Holm, Piotr Skorka, Nigel Stork, Sanej P Suwal, Giedrius Švitra, Ann B Swengel, Scott R Swengel, Nicolas Titeux, Robert Tropek, Olga Tzortzakaki, Chris van Swaay, Rudi Verovnik, Jerome L Wiedmann, Martin Wiemers, Masaya Yago, Hossein Yazdandad, Oz B Yehuda, Konstantina Zografou, Aletta Bonn, Guy Pe'er, Jonathan Lenoir 

Ongoing global change is leading to the widespread redistribution of species1,2. Assessments of shifts in species geographic ranges, however, remain taxonomically biased and geographically limited2, especially for insects. We conducted a global synthesis on butterfly range shifts using a combination of multi-lingual review in 15 languages and expert assessments, compiling data on range shifts for 1758 species (10% of described butterfly species) from 109 countries over the last three decades. In 5 of these countries, over 50% of butterfly species shifted their ranges. Overall, most species showed horizontal range expansion (81%), while 27% contracted their range and 22% shifted in elevation. Expansions were primarily reported in tropical species-rich regions, while 19% of species displayed multiple, concurrent range shifts in different countries, highlighting the complexity of these responses. In addition, there was also variation across families - while one-third of the documented species are nymphalids, pierids and papilionids had the highest proportion of species, experiencing range shift. We pinpoint nine drivers of species redistribution, with climate change and severe weather as most prominent. We suggest a future-focused conservation strategy that emphasises monitoring expansion in underrepresented regions and megadiverse countries, leveraging citizen science, and integrating range shifts into conservation planning.