Number of butterf lies halves in just 40 years

BRITAIN’S native butterflies are dying out – with numbers almost halving since 1976.

Populations have fallen by 48 per cent overall with the worst affected species – the white-letter hairstreak – down by 96 per cent.

Conservationists say the decline is down to intensive farming practices and fewer wild flowers in the countryside.

Mild wet winters and damp summers have also played a part in devastating the UK’s 59 species.

The survey, carried out for the Department for Environment, Food and Rural Affairs (Defra), examined two classes of butterfly – those that are specific to a particular terrain and those that dwell in the wider countryside, farmland or gardens.

Habitat specialists were down 61 per cent, while the latter group fell 41 per cent – an overall drop of almost 50 per cent. The figures do not include migrant species.

Although the specialists were slightly up – 5 per cent – last year, experts say it masks a wider decline in numbers.

Tom Brereton, head of monitoring at Butterfly Conservation, said our recent ‘mild wet winters’ are generally not good for butterflies and moths, adding: ‘We’ve had a run of terrible wet summers as well.’ He added: ‘They are an indicator of the general health of our environment. Butterflies indicate the damage that is being done to the environment that ultimately causes problems both in terms of our quality of life and our economic prosperity as well.’

The survey also found that since 1990, numbers of woodland species have fallen by 51 per cent, reaching a historical low in 2012 as a result of a particularly cold and wet summer. Although they have made a slight recovery, long-term decline has been blamed on a lack of woodland management. Species in severe decline include the brown argus, common blue, gatekeeper, holly blue, and the marbled white. The white-letter hairstreak, named after the ‘W’ markings on its hindwings, has plummeted after the elm trees in which it lived were ravaged by Dutch elm disease in the 1970s and 1980s.

However, all is not gloom. Success stories include the large blue, which became extinct in 1979 but some 28 populations are now thriving in Gloucestershire and Somerset thanks to a conservation project. The heath fritillary, found on Exmoor in Devon and the wetlands of south-east England, has also been saved from the brink of extinction. A Defra spokesman said: ‘We have an ambitious plan to protect and improve our natural environment. Since 2010 we have helped to create over 100,000 hectares of new habitats for nature to flourish. And woodland cover is at its highest level in 700 years.

‘We launched our National Pollinator strategy to raise awareness and help support butterflies and bees to survive and thrive on farms, in towns and across the countryside.’