For humans, when the temperature rises, we tend to cast off heavy, darker colors in favor of lighter fabrics. If for some reason we were incapable of changing our clothes, odds are those of us stuck in darker duds would retreat to cooler climates. According to researchers from Imperial College London, Philipps-University Marburg and University of Copenhagen, that’s exactly what’s happening to butterfly and dragonfly populations as Europe’s climate warms.

“We now know that lighter-coloured butterflies and dragonflies are doing better in a warmer world, and we have also demonstrated that the effects of climate change on where species live are not something of the future, but that nature and its ecosystems are changing as we speak,” concluded Professor Carsten Rahbek, from the Department of Life Sciences at Imperial College London.

That immediacy is perhaps what strikes researchers the most. To them, it’s an indication that global climate change isn’t so much a future problem as it is something that’s happening here and now, and in unpredictable ways.

Just as with humans, darker-outfitted insects absorb are able to absorb more sunlight than lighter ones, thus making their body temperature more sensitive to intense heat. That’s why they tend to stick to cooler climates, and to that end they’ve found that several Mediterranean dragonfly species have expanded their northern range and immigrated to Germany, such as the Southern Migrant Hawker (Aeshna affinis), the Scarlet Darter (Crocothemis erythraea) and the Dainty Damselfly (Coenagrion scitulum). The same is true for some Mediterranean butterflies, who have been found in Germany and continue to expand northward.

To compile the findings, the team used a straightforward combination of digital image analysis (to determine the insects’ coloring) and distributional data. When analyzed together, it showed a clear trend of darker colored insects retreating to cooler northern climates.

Research like this is a valuable tool in communicating the urgency (and far-reaching effects) of global climate change.

“When studying biodiversity, we lack general rules about why certain species occur where they do. With this research we’ve been able to show that butterfly and dragonfly species across Europe are distributed according to their ability to regulate heat through their colour variation. Until now we could only watch the massive changes in the insect fauna during the last 20 years. Now we have an idea of what could be a strong cause of the changes,” said Lead author Dirk Zeuss from Philipps-University Marburg in Germany .