Butterflies seek new habitats as climate changes - study

A recent study in Nature Ecology and Evolution reveals that climate change is significantly altering the habitats of butterflies around the world. Researchers examined the distributions of over 1,700 butterfly species across 105 countries and territories, finding that nearly 80% of the reported shifts in butterfly range were directly linked to climate change and extreme weather events.

These changes occurred due to factors such as land use changes, agriculture, urbanization, habitat fragmentation, and the introduction of invasive species.

Butterflies, known for their sensitivity to temperature changes and dependence on specific host plants, are particularly vulnerable to these shifts. As the planet warms primarily due to burning fossil fuels, some butterfly species are moving northwards or to higher elevations for cooler conditions. However, only 22% of species showed an elevation shift, while 80% expanded their range and 27% contracted it.

Some species had different patterns of response in various regions, highlighting the complexity of their reactions to climate change.

Study co-author Jonathan Lenoir from France's national scientific research centre (CNRS) noted that butterfly species are capable of migrating and shifting their range, which is a positive sign. However, he cautioned that range expansions are easier to detect than contractions. Many observations, including those from citizen scientists, were concentrated near urban areas, which might skew the results.

But Lenoir emphasized that butterflies have limits to their adaptation capabilities, and beyond a certain warming threshold, more species could experience range contractions, leading to rapid and sudden upheavals and potential extinctions.

A 2024 study in Global Ecology and Biogeography found that 84% of approximately 270 butterfly species in Europe would reduce their range by 2080 if global temperatures continue to rise. Lenoir pointed out that some butterfly species may not be able to migrate further north in latitude or higher up in mountain ranges, especially if their habitat is reduced to almost nothing, trapping them.

The authors called for stronger conservation policies, protection and restoration of butterfly habitats, ecological corridors, micro-climatic refuges, and improved biodiversity monitoring through citizen science.

Lenoir emphasized the urgent need to limit global warming to prevent further harm to butterflies and other species. However, the study also highlighted significant knowledge gaps, with only one in ten butterfly species having documented data on range changes, and tropical regions remaining largely understudied.