A large, international team of scientists has determined that one in ten butterfly species globally has shifted its distribution range, with climate change and extreme weather driving nearly 80% of documented movements. The study, the largest of its kind, includes analyses of 6,182 range‑shift records for 1,758 species across 105 countries, drawing on English and non‑English scientific literature as well as 68 expert assessments.
Lead author Shawan Chowdhury, head of the Global Change Ecology Lab at Monash University in Australia, said the findings expose a rapidly changing natural world and major blind spots in how biodiversity change is monitored.
“We found butterfly species shifting their ranges on every continent where they occur. The scale is astonishing, and it’s happening far beyond the well‑studied regions of Europe and North America,” Chowdhury said. “Climate change is now a dominant force reshaping where species can survive. For many butterflies, to survive, the only option is to move, often quickly, to track suitable conditions.”
The study, published in Nature Ecology & Evolution, shows 80% of species expanded their ranges, often moving into newly suitable areas as temperatures rise. At the same time, 27% contracted their ranges, and 22% shifted along elevational gradients.
“Projects like these are difficult to do on a global scale because it requires the efforts of many specialists and historical documents that can be difficult to obtain,” said study co-author Akito Kawahara, curator and director of the McGuire Center for Lepidoptera and Biodiversity at the Florida Museum of Natural History. “It was great to see that McGuire Center could use the power of the data that we have to help contribute to this.”
When the researchers looked at how many species in each country had documented range shifts, five European countries stood out: the Czech Republic, Finland, Luxembourg, Spain and Sweden, each of which has records for more than half of its butterfly species.
A total of 32 countries had documented shifts for at least a quarter of their known butterfly species, and 10 countries for more than half.
“One of the most striking insights is how much evidence we were missing,” Chowdhury said.
“When we included non‑English studies and expert knowledge, a completely different global picture emerged. Without these sources, we would have dramatically underestimated the global patterns of range shifts, especially overlooking key patterns in the tropics, where 80% of insect species live.”
The research highlights severe geographic gaps: Central Africa, Southeast Asia, New Guinea and the Amazon Basin remain critically under‑represented despite being global biodiversity hotspots.
“These are the regions where species are most vulnerable and where we know the least,” Chowdhury said. “Tropical butterflies already live close to their upper thermal limits. Even small increases in temperature can push them beyond their limit, especially when land‑use change is breaking up the very habitats butterflies rely on to move and track suitable climates.”
The authors warn that without equitable, standardized and multilingual biodiversity monitoring, conservation efforts risk being guided by an incomplete and biased evidence base.
“Butterflies are early‑warning indicators. If their ranges are shifting this dramatically, it signals profound changes across ecosystems,” Chowdhury said. “We urgently need coordinated global monitoring, especially in the tropics, to understand what species are doing, where they’re going, and how we can protect them.”
One easy way people can help, Kawahara said, is to regularly observe and document the biodiversity around them.
“By photographing butterflies and uploading images to apps like iNaturalist, scientists can follow trends in which species are present and when and where. This is especially important at a time when the environment is changing rapidly.”
The authors published their study in the journal Nature.
Sources: Akito Kawahara, kawahara@flmnh.ufl.edu;
Shawan Chowdhury, shawan.chowdhury@monash.edu
Media contact: Jerald Pinson, jpinson@flmnh.ufl.edu, 352-294-0452