Butterflies in U.S. Disappearing at 'Catastrophic' Rate with No 'Sign' That It's 'Going to End'

Mar. 15, 2025

Two Giant Swallowtails.Photo:Getty

Getty

A new study has found that the butterfly population in the contiguous United States is rapidly declining — and scientists believe that the decrease is “catastrophic.”

According to Nick Haddad, a Michigan State University ecologist who also co-wrote the study, butterflies are “vanishing” at an alarming rate. Haddad told theWashington Postthat he couldn’t believe some of the results he was seeing at first — but was quickly convinced the situation was dire.

“In my mind, I was nodding, thinking, ‘Oh, they just went out on a bad day,’ ” he told theWashington Post.

“Butterflies have been declining the last 20 years,” Haddad added toCNN. “And we don’t see any sign that that’s going to end.”

A stock image of two tiger swallowtails.Getty

Researchers used more than 12 million butterfly observations from 35 different scientific programs — where both scientists and dedicated butterfly enthusiasts marked the number of insects they saw during one outing — across the county that were taken from 2000 to 2020, making this research the most comprehensive population count of butterflies in the U.S. to date.

“Losing one out of every five butterflies over 20 years should be a big wake-up call to people,” Dr. Eliza Grames, an assistant professor of biological sciences at Binghamton University and co-author of the study, toldCBS News. “These declines are not stopping.”

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Only 3 percent of species populations included in the study increased. Other scientists have taken steps to preserve butterflies — such as the well-known monarch butterfly, whichthe U.S. Fish and Wildlife Service(FWS) proposed listing under the Endangered Species Act in December 2024.

The monarch butterfly’s popular has steadily decreased since the 1980s.Getty

The study says that the use of pesticides (especially insecticides), habitat loss through land development and climate change are all contributing to the loss of butterflies, as the insects' breeding patterns and food sources are disrupted.

According to David Wagner, a University of Connecticut entomologist who was not involved in the study, butterflies can serve as a “yardstick for measuring what is happening” among insects.

“The study is a much-needed, Herculean assessment,” he told thePost,calling the findings “catastrophic and saddening.” “The tree of life is being denuded at unprecedented rates. I find it deeply disheartening. We can and must do better.”

“They’re beautiful, right?” Haddad told thePost. “I do think there’s a way that butterflies enrich our lives through thinking about biodiversity that isn’t possible for all other insects.”

source: people.com