An international team of scientists examined the distributions of 366 species of butterfly and 107 species of dragonfly across Europe. They found that darker species were more common in the colder north and lighter species in the south.
To determine whether climate change had altered the patterns of distribution, they then examined data from between 1988 and 2006. The results showed that darker insects were migrating to cooler climates in the western margins of Europe, the Alps and the Balkans, and that on average, the insects were becoming lighter.
‘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 aren’t something of the future, but that nature and its ecosystems are changing as we speak,’ said Carsten Rahbek of Imperial College London, one of the study’s authors.
‘When studying biodiversity, we lack general rules about why certain species occur where they do,’ said lead author Dirk Zeuss of Philipp University of Marburg. ‘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.’
This story was published in the July 2014 edition of Geographical Magazine