If you’ve noticed fewer butterflies on spring days, you aren’t alone, as experts are warning that butterfly populations are falling drastically.
To shed more light on the issue, Nick Haddad, an ecologist at Michigan State University, joined KCBS Radio. Haddad shared that the decline is happening quickly, and many are still questioning why.
Haddad recently led a study about the declining butterfly populations, which was published in the journal Science, andfound that the issue isn’t in just one region, but across the country.
So what’s behind the decline? Haddad says that there are three main culprits to blame.
“There has to be some general cause of decline,” Haddad said. “The three big factors that we worry about in science and environment are climate change, Habitat loss, and new classes of pesticides used in agriculture and in neighborhoods.And for my part, I’m seeing the effects of new classes of insecticides [becoming] higher and higher as a cause.”
The study found that for 554 species, populations have declined by 22% in the United States. To gather its findings, Haddad and his fellow researchers counted 12.6 million butterflies, analyzed 76,957 surveys, and partnered with 35 monitoring programs to compile data on population trends from 2000 to 2020.
However, when the magnifying glass is used, the data gets more concerning, as for 107 of the monitored species, populations declined by more than 50% over the last two decades, the study found.
“Over the two-decade study period, 33% of individual butterfly species showed significantly declining trends in abundance,” the study said.
Haddad shared that when looking at possible solutions, researchers agreed on two options.
“One is at a big scale, like nationally, my view is we have to reduce the use of insecticides,” he said. “I mean, across the country, we put them on crops even when they’re not needed. And so we can reduce them dramatically and reduce their effects on other insects, like the ones we care about, like butterflies.”
At a more local level, Haddad said that promoting community and home gardens that plant plants for pollinators can help boost populations of caterpillars and butterflies when they become adults.