Butterfly survey reveals mixed picture
Numbers of large blues reached a record high.
The latest data from the UK Butterfly Monitoring Scheme (UKBMS) has revealed a mixed picture for UK butterfly populations.
Half of the 58 species monitored had a better than average year in terms of population size, whilst the other half had a below average year.
The picture is similarly mixed when it comes to long-term trends. About a third of species are showing a significant long-term decline and a third a long-term increase.
The red admiral, chequered skipper, and brimstone had their best years since the UKBMS began in 1976. The red admiral has historically been a migratory species, but as the climate has grown warmer, it has begun to overwinter in the UK. Numbers have increased by 318 per cent since 1976.
Another species which had a good year was the large blue, which also had its best year since records began. The species became extinct in the UK in the 1970s, but has since been reintroduced as part of conservation efforts.
Among the species that had a bad year was the small tortoiseshell. Numbers hit a record low in England, and the species had its second worst year in Wales and joint fifth worst in Scotland. However, it did have its second best year in Northern Ireland.
The number of small pearl-bordered fritillaries was also down, with the species recording its lowest numbers since the survey began. It has declined by 71 per cent since 1976.
The data was recorded with the help of thousands of volunteers at 3,316 sites across the UK.
Marc Botham, butterfly ecologist at the UK Centre for Ecology and Hydrology, said: “Butterflies are an indicator species, meaning they can tell us about the health of the wider environment, which makes the UKBMS data invaluable in assessing the health of our countryside and natural world in general.
“The mixed results this year emphasise the need for continued monitoring and conservation efforts to protect these important species and their habitats.”
Image © Keith Warmington
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