by David Kindy/Smithsonianmag.com
In many ways, monarch butterflies are the poster child of the insect world. Amateur and professional entomologists alike celebrate the insects’ iconic black-and-orange wings.
However, the beautiful butterfly is under severe threat. Its numbers are dwindling precipitously and scientists are not sure why. Populations of eastern monarchs have declined more than 80 percent in the past two decades while western monarchs have fallen 99.9 percent since the 1980s.
A new study has linked climate change a major driver of monarch population loss. Researchers examining data from 18,000 monarch counts in the United States, Canada and Mexico learned the species is extremely sensitive to weather conditions in its spring and summer breeding grounds.
“Yes, climate change is happening,” study author Elise Zipkin, an ecologist at Michigan State University, tells Adam Vaughn of New Scientist. “It looks like it’s affecting monarchs. Now we have this information, we can have a smart plan for what we might do for conservation of monarchs and other wildlife.”
Published July 19 in Nature Ecology & Evolution, this study reviewed information culled from 25 years of population counts. Zipkin and her colleagues discovered that rainfall and temperature deviations from long-term averages over the past 15 years were seven times more impactful than other causes, including herbicides, pesticides and habitat loss.