Moth on brink of extinction found flying at secret Scottish site
The discovery of Dark-bordered beauty males in areas where caterpillars were released boosts optimism that the species can be saved.
A moth on the verge of extinction in Britain and grown in captivity for the first time has been discovered fluttering at a spot where its caterpillars were released. Only three locations in Britain still support the Dark-bordered beauty, but a conservation initiative to create new colonies in the Scottish Highlands is helping to increase its population.
After 160 caterpillars were released at a secret spot in the Cairngorms last summer, newly emerging male moths were discovered in non-lethal light traps last week, boosting optimism that the endangered insect can be successfully restored.
The moth, which is nearly extinct in England and only found in two locations in the Cairngorms, feeds on suckering aspen, a very scarce tree whose young shoots are commonly nibbled by livestock or an abundance of wild deer in Scotland.
In 2022, the Royal Zoological Society of Scotland (RZSS) led the first-ever captive breeding program for the species, collecting 40 dark-bordered beauty moth eggs from the wild and transferring them to a purpose-built breeding facility at Highland Wildlife Park.
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These eggs hatched into caterpillars, which pupated into adults and produced 497 more eggs. 160 caterpillars were released into the wild from this group.
Conservation experts monitoring the site discovered the first moths from these caterpillars in light traps.
"I was peering in the moth trap and I could see one on an egg carton in the trap," said Dr Tom Prescott, the head of conservation for Butterfly Conservation Scotland. I couldn't believe what I was seeing; it was thrilling, adding that “We hope this is just the start of the moth becoming established at this site – it shows that the habitat is correct, and we hope the population will thrive and become sustainable there.”
Conservationists hope to see some female moths at the location during the species' brief flight season, but the RZSS says "painstaking" captive breeding will continue for some time.
Breeding moths will be carefully paired and managed to maintain genetic diversity, while conservationists work with landowners to create other suitable sites with lots of young aspen shoots for future releases and to encourage the species, which is not thought to be particularly mobile, to spread naturally.