Butterflies shift habitats as climate changes, study says

Butterfly species are moving into new areas and retreating from some traditional habitats as climate change alters conditions around the world, according to a study published Wednesday in Nature Ecology & Evolution.

The study assessed more than 1,700 species across 105 countries and territories. Researchers found that nearly 80 percent of reported shifts in butterfly ranges were associated with climate change and extreme weather events.

Other human-driven factors also affected butterfly distributions, including land-use changes, intensive agriculture, urbanisation, habitat fragmentation and invasive species.

The study said 80 percent of species expanded their ranges, while 27 percent experienced contractions. Some species showed different patterns in different regions. Only 22 percent of species showed a shift in elevation.

Study co-author Jonathan Lenoir, an ecologist at France's national scientific research centre CNRS, said the findings showed butterflies could move to adapt to changing conditions. But he warned that some species may not be able to move farther north or higher in mountains as temperatures rise.

Lenoir said island mountain species could become “trapped” as their habitat shrinks and their options for shifting elsewhere narrow.

The authors called for stronger conservation policies, habitat protection and restoration, ecological corridors, micro-climatic refuges and better biodiversity monitoring, including through citizen science. They also said global warming needed to be limited to lower levels.

The authors said knowledge gaps remain: only about one in 10 butterfly species has documented data on how its range is changing, and tropical regions remain largely understudied.