After 25-year absence, rare spider reappears in Scotland’s reforested “lost world”

In a great example of the unexpected biodiversity-enahcing “fringe benefits” of ecological restoration, a survey at Scottish reforestation non-profit Trees for Life’s Dundreggan Conservation Estate in Glenmoriston near Loch Ness have revealed a rare money spider in a find described by experts as “spectacular”.

Of course, most people only consider the “charismatic megafauna” to be spectacular, but true nature lovers know otherwise. With some 100,000 named species of arachnid and 900,000 named species of insect, there’s no question as to who really rules the planet.

The discovery of an adult male of the species Hilaira nubigena at the native forest restoration site in Inverness-shire is the first record of the spider west of the Great Glen for more than 25 years.

The rare arachnid has been recorded from damp moorland above 400m and up to 700m, but little is known about its habits. It may be characteristic of high-altitude habitats such as ‘montane woodland’ – a waist-high mini-forest found on mountainsides, which is home to a unique range of species. Unfortunately this important habitat is overgrazed, and most of it has already disappeared in Scotland.

This really spectacular find shows that the habitat at Dundreggan is rather special,” said Edward Milner, who identified the spider, and who has been studying spiders in Scotland for over 20 years. “Some of the spider species that we find in the montane woodland on the estate are also found in the Arctic. They are adapted to surviving the extreme conditions that we can experience here. I last saw this spider near the summit of Liathach in Wester Ross in June 1986.

The few recent records of Hilaira nubigena in Scotland are all from south of the Great Glen, with a few records from mountains on the west coast. It has only been recorded from 14 sites throughout Scotland, including a recent one above 500m in the Carrifran Valley near Moffat.

Doug Gilbert, Trees for Life’s Operations Manager at Dundreggan, said: “Discovering another rare species in this corner of the Highlands highlights why it’s so important to protect and restore the Caledonian Forest, with its important but vanishing habitats like montane woodland. We hope to carry out further work to find out more about the fascinating species living on Scotland’s highest hills. We’ve already recorded several interesting montane spiders at Dundreggan, and we suspect others are waiting to be found.

The money spider family is a large group of small to minute spiders mostly under 5mm long. Their name comes from the folklore that it’s lucky to get one caught in your hair – and will bring you increased wealth.

The discovery of Hilaira nubigena and other montane spiders adds to Dundreggan’s reputation as a biodiversity-rich “lost world”. Of the more than 3,300 species already found on the estate, some were previously unknown in the UK or Scotland, or feared extinct. The site’s 11 UK biodiversity firsts are a non-biting midge, three sawflies, an aphid, two aphid parasitoids, three fungus gnats, and a mite.

Members of the public can volunteer to help plant trees at Dundreggan as part of Trees for Life’s award-winning restoration of the Caledonian Forest. The charity’s rewilding activity also includes working for the return of rare woodland wildlife and plants, and carrying out innovative scientific research and education programmes.

Photo of the newly-rediscovered Hilaira nubigena © Jens-Kjeld Jensen.

See Trees For Life website.

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