The world’s butterflies are on the move.
Whether it’s the iridescent blue Godartiana byses flitting south in Brazil as temperatures rise or Europe’s endangered Danube clouded yellow losing ground to more intensive agriculture, roughly 1 in 10 of the world’s 19,000 butterfly species appear today in different places than they were once found.
That’s according to perhaps the most thorough accounting to date of how butterflies are changing locations as the planet changes around them, published last week in Nature Ecology & Evolution.
“We found butterfly species shifting their ranges on every continent where they occur. The scale is astonishing,” said Shawan Chowdhury, the paper’s lead author and head of Monash University’s Global Change Ecology Lab in Melbourne, Australia.
This isn’t the first time such butterfly shifts have been documented. But much of the past research has concentrated on insects in North America and Europe, where money and scientific infrastructure support more intensive and long-running research. That, however, isn’t where most butterfly species occur. They are concentrated in the biodiversity hotspots of the tropics.
To remedy this mismatch and create a more comprehensive picture of what’s happening to butterflies, Chowdhury and colleagues went beyond the usual sources of scientific papers. They sought out research published in languages other than English. And they surveyed 68 butterfly experts from 49 countries to get their insights.
“When we included non‑English studies and expert knowledge, a completely different global picture emerged,” said Chowdhury. “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 resulting picture was one of global turmoil, with butterflies buffeted by both climate change and habitat loss. Of the 1,758 species reported to have altered their location, 80% expanded their range, showing up in places where they previously hadn’t been seen, including Brazil’s little Godartiana. Those range expansions were concentrated in the tropics, where insects already live at the edge of the temperature limits they can tolerate.
In contrast, nearly 30% of species lost ground in some places, a phenomenon chiefly documented in Europe and North America. Meanwhile, 22% of species had moved to different elevations, a phenomenon often associated with rising temperatures, which organisms try to escape by moving to higher ground.
While the reasons for these changes are many, two major factors emerged most frequently in the literature. Climate change was identified as a major driver in 79% of the species in which scientists had identified causes of the butterfly movements. Habitat disturbance and agriculture were cited most often in cases where a butterfly species saw its range shrink.
These mass movements of butterflies around the globe highlight the need for conservation initiatives that can aid them, the authors write. That includes identifying and protecting places likely to provide the most hospitable conditions for a species as the climate changes; reducing harm from activities such as farming; preserving land that connects different patches of habitat to aid the butterflies in their movements; and forecasting where species are likely to move when considering what land to protect.
While butterflies are attention grabbing thanks to their beautiful colors and the remarkable metamorphoses they undergo from larva to adult, the alarm over the changes in their locations isn’t just about the insects. It’s also an alert that something bigger is amiss.
Much as Rachel Carson’s book “Silent Spring” tied the pesticide-induced loss of insects to broader ecological mayhem, so people can read a bigger message into the movement of butterflies. “Butterflies are early warning indicators,” said Chowdhury. “If their ranges are shifting this dramatically, it signals profound changes across ecosystems.”
Chowdhury, et. al. “Extensive climate-induced range shifts in butterflies across the globe.” Nature Ecology & Evolution. Aug. 5, 2026.
