Berwickshire and north Northumberland are becoming critical areas for butterflies, according to a new report.
The report – The State of the UK’s Butterflies 2011, by wildlife charity Butterfly Conservation and the Centre for Ecology and Hydrology – reveals that butterfly populations have continued to decline over the last ten years.
But Richard Fox, Butterfly Conservation survey manager, said that north Northumberland and Berwickshire are bucking the UK-wide trend.
“The south of Scotland and the north of England have never had it so good for butterflies,” he insisted.
The Butterfly Conservation charity believes that Northumberland and the Borders reflect the powerful effects of global warming, which are pushing butterflies north as they die out in the south, with a number of species heading north from southern England due to climate change.
The latest report comes from data gathered by two long-running citizen science projects – the Butterflies for the New Millennium recording scheme and the UK Butterfly Monitoring Scheme.
The figures show that the total number of common and widespread butterflies in England fell by a quarter in 10 years, while in Scotland the total abundance of widespread butterflies increased by 11 per cent during the same period.
Experts say the differences are due not only to the changing climate, but to Scotland’s relatively unspoilt landscape. The star player making the most dramatic appearance in the Borders is the Comma, an orange and brown butterfly with scalloped wings and a small but distinctive silver comma-shaped marking on its undersides.
Richard Fox said a number of species were coming to Scotland, but the Comma was a leading example.
“The Borders are the first port of call for butterflies heading north,” he explained. “The Comma is a big success story and a particularly striking example because it hadn’t been recorded in Scotland for about 150 years until a decade ago.”
As well as the Comma, Mr Fox said that the Speckled Wood, Orange-tip, Holly Blue and Small Skipper can now usually be seen in the back garden or while out walking the dog.
He added that butterflies are regarded as the “canaries in the coalmine” for the environment – an indicator species with serious declines possibly representing a wider UK insect bio-diversity crisis.
Paul Kirkwood, director of Butterfly Conservation Scotland, said one of the country’s most important species, the Marsh Fritillary, was also doing well.
Although it had previously been lost from large parts of Scotland, the Marsh Fritillary decline has reversed in recent years and it has expanded from its stronghold in Argyll.
“This is possibility due to weather and to grants from the Scottish Rural Development Plan, which has specifically supported livestock grazing in woodland which creates good habitats for these butterflies,” Mr Kirkwood said.
However, the report said not all varieties were doing well in Scotland, with some specialist species, such as the Pearl- bordered Fritillary, still declining. Mr Fox admitted: “The overall UK assessment shows that butterflies are in a poor state in 21st Century Britain.
“However, we know what to do to reverse the long-term declines of many threatened butterflies and, over the last decade, we’ve proved it can be done on countless local sites across the UK.
“What we now need to do is roll out these successful approaches on a bigger scale.”
Mr Fox said it was vital that the Government’s new approach to ecosystem conservation retains a “sharp focus” on threatened species. “Without this, many butterflies and other wildlife will continue to decline,” he warned.