Butterflies and Climate Change
A butterfly is a mainly day-flying insect of the group which includes the butterflies and moths. Butterflies have large, often brightly colored wings, and conspicuous, fluttering flight. The earliest known butterfly fossils date to the mid Eocene epoch, between 40—50 million years ago. A recent study of the impact of climate change on butterflies suggests that some species might adapt much better than others, with implications for the pollination and plant consumption associated with these and other insect species. The research, published in Ecological Entomology, examined changes in the life cycles of butterflies at different elevations of a mountain range in central Spain. They served as a model for some of the changes expected to come with warming temperatures, particularly in mountain landscapes.
It is a popular belief that butterflies have very short life spans. However, butterflies in their adult stage can live from a week to nearly a year depending on the species. Many species have long larval life stages while others can remain dormant in their pupal or egg stages and thereby survive winters.
The researchers found that butterfly species which already tend to emerge later in the year or fly higher in the mountains have evolved to deal with a shorter window of opportunity to reproduce, and as a result may fare worse in a warming climate, compared to those that emerge over a longer time period.
"Insects and plants are at the base of the food pyramid and are extremely important, but they often get less attention when we are studying the ecological impacts of climate change," said Javier G. Illan, with the Department of Forest Ecosystems and Society at Oregon State University.
"We’re already expecting localized extinctions of about one third of butterfly species, so we need to understand how climate change will affect those that survive," he said. "This research makes it clear that some will do a lot better than others."
Butterflies may be particularly sensitive to a changing climate, Illan said, and make a good model to study the broader range of ecological effects linked to insects. Their flight dates are a relevant indicator of future responses to climate change.
The research examined 32 butterfly species for five years at various elevations in a Mediterranean mountain range, and the delays in flight dates that occurred as a result of elevation change.
The effects of global warming are not all negative. Global warming is rescuing the once-rare brown argus butterfly. It's all about food in this case. Over about 20 years, the butterfly went from a species in trouble to one that is pushing north in Britain, where it found a veritable banquet.
Now, the butterfly lives in twice as large an area as it once did and is not near threatened, according to a recent study in of the journal Science.
For further information see Butterfly Climate.
Butterfly image via Wikipedia.