Butterflywatch: Gatekeepers spread north to take up residence in Scotland

It may have been a fairly awful summer for butterflies but Scotland continues to enjoy some pleasant lepidopteran surprises, thanks to global heating.

Its list of resident species increased by one this year when the gatekeeper , never officially recorded north of the border in the past century, was spotted in several locations. Meanwhile, the elusive white-letter hairstreak , which was only recorded for the first time close to the River Tweed in 2017 , has now been found in Dundee, more than 60 miles farther north.

The gatekeeper – so-called because of its habitat of rough grassland beside hedges and gates – is one of England's commonest butterflies. This year it was found at the Crook of Baldoon RSPB reserve near Wigtown in Dumfries and Galloway, before George Thomson, the author of The Butterflies of Scotland, obtained the first photographic proof – a female in his garden.

Other species that have dramatically expanded their northerly range in recent years include the holly blue, wall brown , small skipper and large skipper. A few species that are struggling farther south, most notably the small tortoiseshell , appear to be doing better farther north.

These welcome movements northwards demonstrate the importance of having corridors of wildlife-friendly habitat to help butterflies – and other species – reach new landscapes in an era of rapid climatic changes.