Imagine spotting a butterfly species in your garden that you have never seen before. You might take a photo and upload it to a citizen science app or tell a local nature group about your new encounter. It feels like a small moment of joy.

Our new global study found one in 10 known butterfly species have already shifted in range.

The data used in our global study were comprehensive: more than 6,180 reports of butterfly range shifts from 565 studies and 68 expert assessments, covering 1,758 species across 105 countries.

Why should people care? Butterflies are part of the living fabric around us. Adult butterflies contribute to pollination. Caterpillars provide food for birds, spiders and other insects. When butterflies disappear, it can signal that the plants, grasslands or woodlands once visited by butterflies are also changing.

This matters for conservation. Many protected areas are based on maps of where species lived in the past. But if butterflies and other species are moving, those maps quickly become outdated.