This year’s increase in butterflies is not proof of a thriving environment in the U.K.

Context

On September 15, 2023, Katie Hopkins, an English media personality and far-right commentator, uploaded a video to her Instagram in which she claimed that the population of butterflies in the U.K. has grown by 338 percent. As butterflies are a marker of a healthy environment, this fact should effectively silence climate and environment activist groups Extinction Rebellion and Just Stop Oil, Hopkins says. The video was reshared by other Instagram accounts. 

But in fact, there are several things wrong with Hopkins’ post. The 338 percent increase was for only one species. Other species saw more modest increases, while others showed a decline. Annual numbers aren’t the best indicators of long-term trends, and over the long term, many U.K. butterflies are in decline due to habitat loss and climate change. 

In fact

On September 15, 2023, the organization Butterfly Conservation published the results of their annual Big Butterfly Count, an effort to track the state of the U.K. butterfly population. The count did show a 338 percent increase compared to last year but for only one species - the red admiral. Other species saw more modest increases, while others are in decline.

“There is a lot of incorrect information in this,” Tom Oliver, professor of applied ecology at the University of Reading, said of Hopkins’ post to Logically Facts. “The 300 percent increase is only true for one species – red admiral – the overall trend across all species in the U.K. was at 34 percent, so an order of magnitude less.”

According to Butterfly Conservation, the red admiral is benefiting from climate change. In a press release, the organization stated that long-term trends show that since the Big Butterfly Count started 13 years ago, many species have significantly decreased. “It is a further warning sign that nature everywhere is in crisis,” Butterfly Conservation said in the statement.

One year’s count of butterflies is not a very good indicator of the overall state of the environment, EJ Milner-Gulland, a professor of biodiversity at the University of Oxford, told Logically Facts. “No, it isn’t – butterfly populations fluctuate a lot from year to year depending on the weather, so short-term (annual) fluctuations are not a good guide to long-term trends in these species,” said Milner-Gulland. 

Professor Oliver said that over the long term, butterflies are good indicators because they are sensitive to the quality of the environment. “Most butterflies have suffered a long-term decline in the U.K., reflecting worsening habitat availability and increasingly from impacts of climate change [...] Drought conditions, as suffered in 2022, have negative impacts for many species, so it is a relief that the weather in 2023 was slightly better for them, but this does not detract from the long-term declines they are facing,” he said.

Richard Fox, Head of Science at Butterfly Conservation, told Logically Facts that in the U.K., long-term trends show that 80 percent of butterfly species have decreased in abundance or distribution since the 1970s. “Half of the remaining butterfly species in Britain are now listed as ‘threatened’ or ‘near threatened’,” he said, with reference to the organization’s Red List.  

The verdict

Though a rise in the UK butterfly population was recorded from 2022 to 2023, many species have suffered long-term decline as a result of habitat loss and climate change. One year’s numbers are not a good indicator of long-term trends or the overall state of the environment.