Many butterflies are brightly-coloured, from the azure glint of the Common Blue, to the burnt orange of the Small Copper. But one of our most intriguing species is a complete master of disguise: the Grayling, as Anthony McCluskey explains in our guest blog today. When they are in flight it’s easy to see this butterfly, as the wings are brown and orange, and the butterflies are often engaged in energetic courtship flights or defending their territories.
When they land though, the wings snap shut and the butterfly can literally disappear in front of our eyes. The undersides of the wings are a mix of grey-brown and light-coloured speckles that look just like gravel or stones. This corresponds incredibly well to the dry stony grasslands that this butterfly breeds in. There are even several recognised sub-species of this butterfly, some of which appear to be adapted to the particular types of plants and rocks of their habitats.
Graylings are now mostly a coastal butterfly, and many inland sites for this species have disappeared. Inland they can still be found in quarries, former industrial sites and along train tracks, where the mix of sparse grass and rocks is perfect for them.
But all is not well for the Grayling; populations have crashed in recent times, and in Scotland it is estimated that the butterfly has declined in abundance by almost 90% over the past thirty years. The story across the UK is bleak too, with declines in abundance of almost 60% in the past forty years reported.
Despite this, it’s still possible to find this butterfly in what seems the most unlikely of places: the heart of Edinburgh! Around Edinburgh there are the remains of ancient volcanoes – Edinburgh Castle is built on one, and Arthur’s Seat is another. The rock that make up these features is hard, and the soil is thin – a perfect home for this elusive butterfly! Similar rocks can be found at Calton Hill, and the ridge of rock faces running parallel to Calton Road. And despite the butterfly’s camouflage, it’s easy to see them there in the summer. They mostly fly from early July to mid-August here, and if it’s a sunny day you’ll see them in this area. I’ve even spotted them drinking nectar from Buddleia bushes on Regent Road!
The habitat of the Grayling and other butterflies is threatened by shrubs like Gorse, which can get a hold on the thin soil and shelter out the low-growing wildflowers and grasses. So to help Graylings at Calton Hill and Holyrood Park I’ve been working with volunteers to control the gorse. It’s a prickly job, but a good one to warm us up in winter! Volunteers have also been recording Grayling numbers at Holyrood Park and Calton Hill, and in 2019 they had a real bumper year, with twice as many recorded.
Our next outing to Holyrood to control gorse will be on Sunday 1st March, and you’ll find the details of it and all our events on our events webpage, here: https://butterfly-conservation.org/events/scotland
Anthony works for Butterfly Conservation as the Helping Hands for Butterflies Project Officer. His work to support volunteers recording butterflies, and to create and maintain butterfly habitats, is supported by funds from the National Lottery Heritage Fund and Scottish Natural Heritage. The work at Holyrood Park and Calton Hill has been supported by Historic Environment Scotland and City of Edinburgh Council.