A global study analyzing 1,758 butterfly species across 105 countries has found that one in ten known butterfly species has already shifted its range.
The research, led by scientists from Monash University, the German Centre for Integrative Biodiversity Research (iDiv), the Friedrich Schiller University Jena, and the Helmholtz Centre for Environmental Research (UFZ), indicates that climate change and extreme weather events are the most common reasons for these shifts.
Range expansions were observed across all continents, particularly in the tropics, whereas range contractions were primarily noted in Europe and North America.
Of documented butterfly species that shifted, those expanding their ranges moved latitudinally or longitudinally.
According to the study, approximately 27% of butterfly species have reduced their range, while 22% have shifted their position up or down slopes on hills or mountains.
Shifts in elevation were observed almost exclusively in the Northern Hemisphere.
Regional impacts and species examples
In Southeast Asia and Australia, the tawny coster (Acraea terpsicore) has expanded its range. In Brazil, the butterfly (Godartiana byses) has expanded from Rio de Janeiro and Bahia into São Paulo. Conversely, in Germany, the cranberry fritillary (Boloria aquilonaris) has lost much of its original habitat due to bog drainage, and in Romania, agricultural intensification has been linked to a severe range contraction of the danube clouded yellow (Colias myrmidone).
The study also noted that the small blue (Cupido minimus) has lost 40% of its habitat in the United Kingdom over the past 150 years.
While some species are declining, the Eltham copper butterfly in Melbourne, Australia, has shown signs of recovery following community habitat restoration. Chris Farrow, a biodiversity officer at Yarra Valley Water, stated the species had been making a comeback due to community impact.
Despite the scope of the research, which utilized data from more than 6,180 reports of butterfly range shifts, including 565 studies and 68 expert assessments, significant data gaps remain. Researchers noted a lack of data regarding butterflies in Central Africa, Southeast Asia, New Guinea, and the Amazon Basin.
Butterflies are early‑warning indicators and are signalling a warning across the entire planet.
Dr. Shawan Chowdhury, head of Monash University’s Global Change Ecology Lab, said the study revealed the astonishing scale of change driven largely by climate change and extreme weather.
