A new study published by the journal “Science” has found that butterfly populations have decreased up to 22 percent over the span of 20 years. The study looks at 554 recorded butterfly species across the United States.
The study, titled “Rapid butterfly declines across the United States during the 21st century,” counted 12.6 million butterflies, analyzed the research of 76,957 additional surveys on the subject and partnered with 35 monitoring programs to examine butterfly population trends from 2000 to 2020.
“Our national-scale findings paint the most complete – and concerning – picture of the status of butterflies across the country in the early 21st century,” the study said.
Approximately 107 butterfly species declined by more than 50 percent, in between 2000 and 2020, whereas only three percent of species showed any signs of population increase.
“Over the two-decade study period, 33 percent of individual butterfly species showed significantly declining trends in abundance,” the study stated.
Across the United States, butterfly populations are dropping dramatically, but populations across the southwest area have seen more decreases in the population than any other area.
While the study focused on butterfly populations across the U.S., the study’s results are comparable to what other researchers are seeing across Europe. One point made in the study is a concern over the extremely limited data on butterfly populations in tropical areas.
Dr Matt Forister, a biology professor at the University of Nevada-Reno, and co-author of the study, stated, “suggestions that declines could be worse there [tropical climates] because the ecosystems are more sensitive to changing precipitation patterns.”
Significant drops in butterfly populations are due to several factors, with one of the largest factors being rising temperatures and changing climates according to the study.
“With climate change, butterfly species in North America may find the southern limits of their ranges becoming too warm while the northern limits of their range become more hospitable,” the study said.
