Study: Butterfly Ranges Are Shifting on Every Continent
An analysis of 6,182 records covering 1,758 butterfly species from 105 countries finds ranges shifting on every continent, with 79 percent of the shifts linked to climate and extreme weather.
Butterfly ranges are shifting on every continent where the insects live, according to a global analysis led by researchers from Monash University in Australia, the German Centre for Integrative Biodiversity Research (iDiv), Friedrich Schiller University Jena and the Helmholtz Centre for Environmental Research (UFZ). The study, published in Nature Ecology & Evolution (DOI 10.1038/s41559-026-03117-y), covers 1,758 species, roughly a tenth of all butterfly species described so far. Climate change and extreme weather were linked to 79 percent of all the range shifts recorded.
Until now the picture was narrower than commonly assumed. A landmark study led by Camille Parmesan, published in Nature back in 1999, showed that European butterfly ranges were moving northward, and for decades afterward the literature on the subject stayed largely European and North American. The new paper is the first to break out of that circle, since its authors drew on scientific literature in languages other than English as well.
How the study was done
The authors worked through 6,182 records of range shifts drawn from 105 countries, plus 68 expert assessments from butterfly specialists. The paper’s lead author is Dr. Shawan Chowdhury, formerly a researcher at iDiv, the University of Jena and UFZ, now based at Monash University in Melbourne. He said in a statement issued alongside the study:
We found that butterfly species are shifting their ranges on every continent where they occur. The scale of it is staggering, and it’s happening far beyond the well studied regions of Europe and North America.
Broken down by type of shift, the numbers look like this:
- 80 percent of species expanded their range
- 27 percent of species showed range contraction
- 22 percent of species shifted the elevation at which they live
The totals add up to more than a hundred percent because many species showed more than one type of shift at once, so the same species can appear in two or three categories. That matters when reading the percentages, since it’s easy to mistake them for separate groups of species.
What’s happening where
The geographic pattern isn’t uniform. Horizontal range expansions were recorded on every continent, and they were most numerous in tropical countries. Range contraction was more common in temperate zones, in Europe and North America. Elevation shifts, meaning species climbing toward mountain habitats, were almost exclusively tied to the northern hemisphere.
In ecology, butterflies have long served as an early indicator of change, since they live short lives, reproduce quickly and are sensitive to temperature and to the availability of host plants. If their ranges are moving this much, it’s a sign that things measured more slowly are changing too.
Why the data isn’t equally good everywhere
The study also exposes a problem that isn’t biological but organizational. Czechia, Finland, Luxembourg, Spain and Sweden monitor more than half of their butterfly species. Most other countries track less than ten percent, a result of weak monitoring and gaps in the data. Serbia is not among those five.
The biggest gaps remain in central Africa, Southeast Asia, New Guinea and the Amazon basin, precisely the regions with the greatest species diversity. The authors warn that without consistent, standardized, multilingual biodiversity monitoring, conservation measures rest on an incomplete foundation.
Limits of this analysis
The paper is a synthesis of already published range-shift records, not new fieldwork, so it inherits every weakness of the material it draws on. Wherever butterflies are monitored more closely, more shifts get recorded, which doesn’t mean more shifts are actually happening there than in unmonitored areas. The sample of 1,758 species covers about ten percent of known species and isn’t random.
The link to climate change that the authors report for 79 percent of cases is a statistical association, not proof that climate is the sole cause behind any single shift. Habitat loss, changes in farming practices and pesticide use are all acting at the same time, and in most cases can’t be teased apart from the existing records. The study shows the scale of the phenomenon and its geographic spread, not the mechanism behind any individual species.
