80% of butterflies in UK have decreased since 1970s with major declines in Northern Ireland
The State of the UK’s Butterflies 2022 report, released today by wildlife charity Butterfly Conservation, has revealed the alarming news that 80% of butterflies in the UK have declined since the 1970s.
Decreases in butterfly populations on this scale are a huge cause for concern as butterflies are an integral part of the UK ecosystem and their precipitous decline is a clear warning signal of the wider biodiversity crisis.
Many, though not all, butterfly species in Northern Ireland have been monitored as part of the report. The monitored species show a 17% decrease in abundance and a 10% decrease in distribution. The Wall butterfly appears to be on the verge of extinction. Having formerly been found across Northern Ireland, recently there have only been occasional sightings from the Co. Down coast. The Small Heath is also in trouble having lost 40% of its distribution since 1995. More data are needed in order to assess trends of some of the rarest and most threatened species in Northern Ireland, species which are seeing greater declines across the UK as a whole.
Scientists at Butterfly Conservation are today warning that time is running out for UK’s butterflies as long-term trends show that most butterfly species have declined in either abundance, distribution, or both in the past five decades.
Habitat loss across the UK has led to dramatic declines in those species that require flower-rich grassland, heathland, and woodland clearings to thrive. These specialist species have, on average, decreased by more than a quarter (27% decrease) in abundance and lost over two-thirds (68% decrease) of their distribution since 1976.
Butterfly species that can breed in the farmed countryside and urban areas have fared less badly, but as a group they have still declined by 17% in abundance and 8% in distribution at the UK level.
However, despite the gloomy picture painted by the long-term trends, the report points to numerous examples proving that targeted conservation action can turn around the fortunes of threatened butterflies at site, landscape, and national levels. Trends for the Cryptic Wood White, which occurs nowhere else in the UK, have improved since previous assessments and other species that appear to be experiencing recent upturns in their fortunes include Dark Green Fritillary, Silver-washed Fritillary and Holly Blue. These three species are continuing to expand across Northern Ireland, where suitable habitats exist.
Head of Science for Butterfly Conservation, and lead author of the report, Dr Richard Fox, noted: “This comprehensive stock-take of the state of the UK’s butterflies reveals the huge scale of the challenge to halt and reverse the decline in butterfly populations in the years ahead. Thanks to tens of thousands of people who contribute sightings through projects such as the UK Butterfly Monitoring Scheme and Big Butterfly Count, we have amazing data to plot the changing fortunes of our butterflies. What is needed now is a step-change in government support to bring butterflies and other wildlife back to the UK’s nature reserves, farmland, forests and built-up areas.
“We know that where conservation action is carefully targeted and sustained in the long-term it has real impact. Butterfly Conservation continues to work in partnership with other organisations, communities and landowners, on many projects that are halting declines and turning butterfly numbers around. However, the scale of the decline in the UK’s butterflies has reached a point where much more resource is urgently required.”
Julie Williams, CEO of Butterfly Conservation, said: “This report is yet more compelling evidence of nature’s decline in the UK. We are totally dependent on the natural world for food, water and clean air. The state of our species and habitats shows that the natural world is in trouble. We need swift and effective action on this. The decline in butterflies we have seen in our own lifetimes is shocking and we can no longer stand by and watch the UK’s biodiversity be destroyed.”
The State of the UK’s Butterflies 2022 has been produced by Butterfly Conservation working together with the UK Centre for Ecology & Hydrology and British Trust for Ornithology. The report is based on nearly 23 million butterfly records, almost all of which were contributed by volunteer citizen scientists, that assesses the UK’s 59 species of breeding butterflies.