The latest annual results from the UK Butterfly Monitoring Scheme (UKBMS), led by Butterfly Conservation, the UK Centre for Ecology & Hydrology (UKCEH), British Trust for Ornithology (BTO) and JNCC, have recently (Friday 22 March 2024) been published.
These results present butterfly population trends from 1976 to 2023 at a UK level for 58 of the 59 regularly occurring species. Overall, the latest findings show a mixed picture. Around half of species at monitored sites had a better than average year, while the other half were below average, with 2023 ranking 23rd in the 48-year series.
Of note are four species which had their best year on record at a UK level: Chequered Skipper, Brimstone, Red Admiral, and Large Blue; whilst two species recorded their worst year on record: Small Pearl-Bordered Fritillary and Small Tortoiseshell.
Butterflies are one of the best monitored groups of animals in the UK – the UKBMS began in 1976 and is one of the world's longest-running insect monitoring schemes. The scheme now records data on over 3,000 sites per year and the resulting dataset is a crucial resource for understanding long- and short-term changes in butterfly populations, including natural annual fluctuations due to the weather, and longer-term trends driven by human activity. The results can also show how conservation efforts make a real difference, with 2023 being an excellent year for Large Blue, which recorded its best year yet in 2023 following its reintroduction to the UK after becoming extinct in the 1970s.
Data are collected by thousands of dedicated volunteers, without whom this invaluable dataset would not be possible to generate or maintain. The UKBMS partners are incredibly grateful to each and every volunteer for their contribution.
Chris Tuckett, JNCC Chief Officer Strategy and Impact said: "The evidence produced through environmental monitoring, such as the UK Butterfly Monitoring Scheme (UKBMS), demonstrates the vital role these schemes play in helping us understand the effects of pressures on the natural environment and, equally importantly, how efforts to address these pressures through nature conservation and recovery can be effective in reversing decline.
"JNCC has supported these schemes, which involve thousands of dedicated volunteers, for over 30 years, and remains committed to continuing to support them in the future."
For more information about the latest results, visit the UK Butterfly Monitoring Scheme website.
