(WWJ) - Butterfly researchers across the country have compiled decades of research and made a startling discovery: populations of butterflies are dwindling.
Nick Haddad, a professor of integrative biology at Michigan State University, spoke to WWJ’s Jon Hewett about the impact this discovery has on the country. Haddad said the studies that were conducted had results that were “unbelievable.”
“Across the United States, across different studies, people collecting data in different ways, found a consistent result,” he said. “About a quarter of butterflies have been lost over the last 20 years.”
Butterflies play a significant role in ecosystems. They, along with other insects, provide food to other animals, namely birds. Haddad said there has been a drop in bird populations in the eastern United States that is close to the drop in butterflies, but there isn’t enough data to say one is caused by the other.
Butterflies are also excellent pollinators. One of Haddad’s students conducted a study of pollinators on cotton in Texas. Butterflies pollinate enough cotton in Texas to account for tens of millions of dollars, he said.
Children and adults are able to learn about the world through butterflies. Whether it’s watching them change from caterpillars to butterflies, seeing the Monarchs migrate each year or just observing them in a garden, people can see a piece of nature that can be difficult with other species.
The data showed that all trends have been downward, meaning in the populations observed, none showed any growth over the course of the studies. Haddad said research shows that butterflies in the north have populations dropping a little slower than in the south, which could in part be due to lower temperatures.
There are three factors the studies show could be impacting populations, but Haddad said the causes weren’t the main focus of the research. Climate change, especially rising temperatures, habitat loss and use of insecticides in agriculture, lawns and the environment could all be causing the decline.
“Separately, some colleagues and I did an ‘apples to apples’ comparison,” he said. “Across Michigan and the U.S. Midwest, we had the data on the butterflies, but we also got data on temperature, rainfall, habitat types and use and on insecticides. In that study insecticides rose to the top as a leading factor causing decline.”
Haddad said other insect populations may also be declining at a similar rate because they are affected the same way butterflies are, but it’s more difficult to observe them. Other insects can be hard to differentiate because they look similar, and they can have huge numbers.
He described butterflies as a “canary in a coalmine,” adding that people need to take the decline seriously and begin to look at what is causing it and what can be done to prevent it from getting worse.
The data was collected by thousands of people conducting tens of thousands of surveys that resulted in millions of records of butterflies. The study wasn’t just done by scientists. People who are interested in nature or gardening also participated.
There are many monitoring groups that allow the public to submit information about butterfly populations, which can then be studied by researchers. The Michigan Butterfly Network is part of the Kalamazoo Nature Center, and not only offers people resources on butterfly populations, they also offer training on how to effectively monitor butterflies.