US lost a fifth of all butterflies within a couple of decades

[David Lazarus]

Frightening!

https://www.bbc.com/news/articles/cwyjkn729gpo



edit - thanks Guy url corrected

[Padfield]

Hi David. You accidentally included your own words in the URL link, so it doesn't work. I could have edited your post but never do this without asking first, so here's the real link:

https://www.bbc.com/news/articles/cwyjkn729gpo

Now I'll read it ...

Guy

[aeshna5]

Sadly over the next decade the fall is likely to be even more severe with the anti-environmental policies of the despicable Trump.

[David Lazarus]

Unfortunately, I do not have access to the science behind the news report - but below are the editor's summary and the abstract:

Rapid butterfly declines across the United States during the 21st century

Edwards. C.B. et al Science 6 Mar 2025 Vol 387, Issue 6738 pp. 1090-1094

Editor's summary
Reports of declining insect populations have received widespread media attention, but evidence for declines has been variable across regions and taxonomic groups. Edwards et al. examined trends in the most surveyed taxon: butterflies (see the Perspective by Inouye). Combining data from 35 citizen science programs across the continental US, the authors found declines in overall butterfly abundance over the past 20 years across almost all major regions. Two-thirds of studied species showed declines of more than 10%. Many insects have the potential for rapid population growth and recovery, but habitat restoration, species-specific interventions, and reducing pesticide use are all likely needed to curb population declines.
—Bianca Lopez

Abstract
Numerous declines have been documented across insect groups, and the potential consequences of insect losses are dire. Butterflies are the most surveyed insect taxa, yet analyses have been limited in geographic scale or rely on data from a single monitoring program. Using records of 12.6 million individual butterflies from >76,000 surveys across 35 monitoring programs, we characterized overall and species-specific butterfly abundance trends across the contiguous United States. Between 2000 and 2020, total butterfly abundance fell by 22% across the 554 recorded species. Species-level declines were widespread, with 13 times as many species declining as increasing. The prevalence of declines throughout all regions in the United States highlights an urgent need to protect butterflies from further losses.

This seems to be the case in most countries across most continents - I expect declines in butterfly numbers and occurrence are similar in continental Europe but others on this site will know more about that. The State of the UK's Butterflies xxxx Report has not been good reading for many years now and over the next 10 years I want to track distribution and abundance at a county level for the 34 species of butterflies found in Essex & north-east London [vice-counties of North & South Essex]. I am not sure the end of my project will provide very good reading either, sadly.