04/09/2012 //  Kristin Pene, Research Associate

Do butterflies catch your eye? They sure catch mine. And so does research on butterflies and climate change.

In college, working as a greenhouse manager for a lab that studied how well certain butterfly species might adapt to warming, I came to see the insects as tiny “thermometers.” As invertebrates, butterflies have little control over their own body heat and so are very sensitive to temperature variation. And because caterpillars and butterflies prefer to feed on specific plants, they can be heavily impacted by the changes in plant life that shifting temperature and rainfall patterns bring.

A new study out of Stanford University confirms these ideas. Specifically, the research suggests that the early arrival of spring (or early snowmelt) in the Colorado Rocky Mountains negatively affects the growth rate of its populations of Mormon Fritillary butterflies, for two reasons:

1. An early disappearance of snow cover exposes plants to early frosts, which kills buds of the flowers from which butterflies prefer to sip their nectar. Because the amount of nectar available to female butterflies corresponds to the number of eggs they lay, an early spring can mean fewer eggs.
2. In the same way that an early frost kills flower buds, it kills caterpillars directly – before they have a chance to form a chrysalis and transform into a butterfly.

Just as butterflies are sensitive to extreme cold, they’re sensitive to too much heat. As the climate warms, some butterfly populations are moving into shadier areas of their habitats (like forests) or shifting their entire range north into cooler climates. But recent studies from Europe show that butterflies there aren’t moving into shadier parts or up north fast enough. In other words, climate change is outpacing their efforts to adjust.

All this recent research on butterflies and climate change gives cause for concern. Butterflies, after all, are more than just a treat to watch as they flutter by. As pollinators, they play a critical role in the healthy functioning of ecosystems. This means if climate change spells problems for butterflies, it likely indicates trouble for the rest of us, too

Source: climaterealityproject.org