2 days Ago By [email protected] (Austin Williams)
Researchers note how greenhouse gas emissions are impacting sea-ice and polar bear subpopulations. US butterfly populations have declined by 22% since 2000, with 114 species showing significant drops. A study published in Science found insecticides, climate change, and habitat loss are driving the decline.
The Southwest saw the largest losses, with butterfly numbers down by more than half in Arizona, New Mexico, Texas, and Oklahoma. LOS ANGELES - Butterflies are disappearing across the United States, with populations down 22% since 2000, according to the first nationwide analysis of their numbers. The study , published Thursday in Science, found that climate change, habitat destruction, and increased insecticide use are driving the decline.
Researchers analyzed nearly 77,000 surveys covering 12.6 million butterflies and found that 114 species are in significant decline, while only nine species have increased. Scientists say the loss is alarming—not just for butterflies, but for the ecosystems they help sustain.
By the numbers: David Wagner, an entomologist at the University of Connecticut, called the findings "catastrophic and saddening." He told the Associated Press that while a 1.3% annual decline may seem small, it compounds over time.
"In just 30 or 40 years, we are talking about losing half the butterflies (and other insect life) over a continent," he said. Butterfly populations in the lower 48 states have dropped significantly over the past two decades: 22% decline in total butterfly populations since 2000. An average drop of 1.
3% per year. Scientists analyzed 12.6 million butterflies across nearly 77,000 surveys to track trends.
114 species have seen significant declines, while only nine species have increased. Some species have experienced drastic population losses: The red admiral butterfly, known for landing on people, is down 44%. The American lady butterfly, recognized by its eyespots, has declined 58%.
Even the invasive white cabbage butterfly, which typically thrives in most environments, has dropped 50%. FILE - A Red Admiral (Vanessa Atalanta) butterfly sits on a pear tree in a garden. (Photo by Ian Forsyth/Getty Images) The backstory: Scientists say the crisis is driven by three main factors: climate change, habitat loss, and insecticide use.
Insecticides are the biggest threat, especially in agricultural areas, where their increased use has disrupted butterfly reproduction and food sources. Rising temperatures and shifting weather patterns are also making warmer regions less hospitable, while habitat destruction from urban expansion and farming continues to shrink butterfly populations. Without intervention, experts warn these declines could accelerate.
Dig deeper: The most severe losses were recorded in the Southwest, where butterfly numbers have dropped by more than 50% over the past 20 years. Arizona, New Mexico, Texas, and Oklahoma were hit the hardest. "It looks like the butterflies that are in dry and warm areas are doing particularly poorly," said lead author Collin Edwards, an ecologist and data scientist at the Washington Department of Fish and Wildlife.
Butterflies that live in both southern and northern regions are faring better in cooler areas, researchers found. Why you should care: Experts warn that the decline in butterflies is not just a loss of beauty—it could have real consequences for ecosystems and agriculture. Cornell University butterfly expert Anurag Agrawal said the crisis raises concerns for the future of humans as well.
"The loss of butterflies, parrots, and porpoises is undoubtedly a bad sign for us, the ecosystems we need, and the nature we enjoy," Agrawal said. "They are telling us that our continent's health is not doing so well." Butterflies also serve as pollinators, playing a key role in the reproduction of plants and crops.
They are particularly important for pollinating cotton fields in Texas, researchers said. What's next: Despite the alarming decline, scientists say it’s not too late to reverse course. Habitats can be restored, and butterfly populations can recover if action is taken.
"You can make changes in your backyard and in your neighborhood and in your state," Haddad said. "That could really improve the situation for a lot of species." The Source: This report is based on findings published in Science and expert commentary from entomologists and researchers cited by The Associated Press.
Additional details were provided by conservation experts studying butterfly populations across the United States..
