Historic milestone reached as first ever release of rare moth takes place in the Cairngorms National Park to boost threatened species

Historic milestone reached as first ever release of rare moth takes place in the Cairngorms National Park to boost threatened species - Royal Zoological Society of Scotland

The Royal Zoological Society of Scotland (RZSS) have participated in the first ever releases to boost Britain’s wild population of threatened dark bordered beauty moths as part of the Rare Invertebrates in the Cairngorms (RIC) partnership.

Following a successful first breeding season for the extremely rare native species at Highland Wildlife Park, home to wildlife conservation charity RZSS, RIC partners released 160 dark bordered beauty caterpillars into a specially selected site in the Cairngorms National Park. Establishing new populations of this species is vital, as habitat loss has meant there are currently only three small populations across Britain – two in Scotland and one in England.

In Scotland, dark bordered beauty caterpillars are reliant on aspen suckers, which require protection from grazing to thrive and expand. In the wild, sites with suitable habitat are fragmented, with large distances between them so the moths are not currently able to disperse to new sites themselves. As part of habitat management efforts, RIC have been undertaking surveys to find new sites of suckering aspen and working with landowners to try and help create better habitat for the moths to be released into.

In 2022, 40 dark bordered beauty moth eggs were collected in the wild and transferred to a purpose-built breeding facility at Highland Wildlife Park. These eggs hatched out into caterpillars, pupated into adults and produced a further 497 eggs, making for a successful first breeding season. Most of those eggs hatched into caterpillars that have now been released, while the rest of this year’s caterpillars are currently pupating. A number of individuals will remain at the facility as part of the conservation breeding programme, while others will be released into the wild as adults at the same site as the caterpillars.

Dr Helen Taylor, Conservation Programme Manager at RZSS said “This is an incredible day for dark bordered beauty moths in Britain. Invertebrates form a crucial part of our ecosystems but are often overlooked. We are excited to take these steps to help restore dark bordered beauty moth populations and uncover more about this elusive species. Our charity’s dedicated team’s close monitoring of our conservation breeding population is already providing new insights into reproductive and ecological behaviours that have never been observed before.”