Butterfly Conservation (BC) Scotland and Network Rail have joined forces in the Scottish Highlands to create new habitat for one of the UK’s rarest moths.
The Small Dark Yellow Underwing can only be found in Scotland and 90% of all sightings are recorded within the Cairngorms National Park, but numbers are dwindling and no adult moths were seen at all between 2011 and 2014.
Earlier this month volunteers from BC’s Highlands and Islands Branch and staff from Network Rail improved a former site for the day-flying moth, in the hope of increasing its numbers in the Cairngorms.
The railway embankment on the main Perth to Inverness line, just south of Newtonmore, was once favoured by the Small Dark Yellow Underwing because of the presence of Bearberry – the only foodplant of the moth’s caterpillar.
BC’s Senior Conservation Officer for Scotland, Tom Prescott, said: “This low growing evergreen plant had nearly disappeared from the land near Newtonmore, which had become too shaded and overgrown with leggy heather and broom.
“The volunteers worked really hard to clear scrub from the area and we’re hoping that the Bearberry plant - which is so vital to this moth’s survival - will once again thrive and spread out on to the newly opened ground.
“It’s been great to work in partnership with Network Rail and we are hoping to continue working together to help this moth and other species on their land.”
The Small Dark Yellow Underwing can be seen flying dyring the day in May and is most active during sunshine, when it can be found nectaring on flowers, particularly Bearberry.
In the afternoon and especially during dull weather, the moth can be found resting on rocks or posts.
The caterpillar feeds on Bearberry during the summer, but as they overwinter as a pupa, it will take at least two years before any increase in the population will be seen as a result of this recent conservation work.
Wildlife enthusiasts visiting the Cairngorms National Park are being encouraged to report any future sightings of the moth to BC’s Highlands and Islands Branch.
The Small Dark Yellow Underwing can be identified by a large white kidney-mark on its dark grey/black forwing and it has a distinctive yellow and black-bordered hindwing, which remains hidden when at rest.
Keira McLuskey, Environment Specialist at Network Rail Scotland, said: “It’s great to help support Butterfly Conservation and do our bit to improve the environment for the Small Dark Yellow Underwing. Network Rail is committed to helping the species that live along our infrastructure thrive, whether that’s by building tunnels under lines so hedgehogs can safely cross, rehoming badgers living in the path of railway expansion or something as simple as just cutting back vegetation. We look forward to working with Butterfly Conservation again in the future.”