Quirks & Quarks

Climate Change is Shrinking Arctic Butterflies

The increased metabolic demands of a warmer environment is resulting in selection for smaller butterflies which is reducing the distance they travel.

As the Arctic warms, butterflies use more energy, and are decreasing in size

The Arctic Fritillary butterfly Boloria chariclea (Toke T. Hoye)
The effects of climate change in the Arctic are usually measured in terms of diminishing ice cover. As for the effect on wildlife, it is the polar bear that gets most of the attention. Butterflies, on the other hand, do not come to mind as an Arctic species, let alone one that suffers due to rising temperatures.

But a new study by Dr. Joseph Bowden, a Canadian post-doctoral researcher at The Arctic Research Centre at Aarhus University in Denmark, has found that two species of butterfly - the Arctic Fritillary and the Northern Clouded Yellow - are getting smaller. Warmer temperatures are resulting in a greater metabolic cost for the butterflies; consequently, their wingspan has decreased by as much as 5 percent since the mid-1990's.

With smaller wings, the butterflies cannot cover as much area, which is leading to a reduction in the gene pool. This trend will likely continue, but the end result is not well understood at this point.

Related Links

Paper in the Royal Society Biology Letters
- Aarhus University release
- Smithsonian Magazine story
Discovery story