Dorset scientists warn time's running out for butterflies
Butterfly Conservation's released their latest monitoring survey
Scientists in Dorset are warning time is running out for our butterflies.
Butterfly Conservation claims last summer's extreme heat and drought had a major impact on numbers.
Many, like the Small Pearl-bordered Fritillary and Small Tortoiseshell, struggled to breed or make it through to adulthood.
Butterfly Conservation’s Head of Science, Dr Richard Fox, said:
“Overall, the data for 2022 tells us that it was an average year for butterflies. However, it was a year of two halves with butterflies seen early and in about average total numbers (compared to the last 10 years) from April – July but then in greatly reduced abundance after the summer heatwave and drought. In general, warm, sunny weather is good for butterflies as they can be active, finding food, mating and laying eggs.
"But drought is a major problem as plants wither and die, meaning female butterflies may struggle to find anywhere to lay their eggs, or there is not enough food for the caterpillars when they hatch.
“The knock-on effect is fewer butterflies in the following generation. We have already seen an indication of this in the 2022 data for some of those species with a generation that flies in late summer and autumn, and sadly we can expect to see a decline in numbers of other species in 2023 too.”
It’s not the first time butterflies have been affected by drought in the UK.
Data gathered by the UKBMS has shown serious negative impacts of droughts on butterflies in 1976 and 1995.
Some species have never recovered their former abundance levels after the 1976 drought, although habitat destruction is likely to be a major factor in their failure to bounce back.
It's been a good year for other species though - like Purple Emperor, Large Blue, Chequered Skipper and Dark Green Fritillary.
They've all been the focus of targeted conservation work over the last few years.
Dr Marc Botham, Butterfly Ecologist at the UK Centre for Ecology & Hydrology, said:
“In 2022 we collected data from over 3,000 sites and we are incredibly grateful to the thousands of volunteers who carry out monitoring and maintain this invaluable long-term dataset. This enables scientists to measure how butterflies are faring as well as assessing the health of our countryside generally. The UKBMS data are vital in assessing the effectiveness of government policies and progress towards the UK’s biodiversity targets.”
Nature Minister Trudy Harrison said:
"Our beautiful butterflies are at risk from a changing climate and human activity. We have set out clear steps to enable nature's recovery through our Environmental Improvement Plan and Pollinator Action Plan, which will help us meet our legal target to halt the decline in nature by 2030.
"The impacts of warm and dry weather last year are a cause for concern, but it is encouraging that the last decade has seen most species stabilise. In particular, I welcome the findings that the Large Blue and the Purple Emperor, two wonderful and unique species people may recognise from Wild Isles, both experienced their second best year on record in 2022."