4 Nov 2025

Scarce moth sighted at Trust nature reserve

Written by Paul Williams

Rare moth discoveries at Grey Mare's Tail

Transcript

Hi, I'm Ishbel Hayes. I'm the Seasonal Ranger here at Grey Tale, which is one of our National Trust for Scotland reserves down in the southern uplands.

We're out here this evening, just around about sunset, to set a moth trap. That's this contraption next to me. We pop it out in the evening with a light on top, and moths are drawn in. We come back in the morning, see what we've caught, record them, and then let them all go again. So, nothing's been harmed, but it gives us a snapshot of which moths we've got flying on the reserve.

So, it's time to put the trap out. So, we'll go and see how that works. To set the trap, we use a light trap to catch them. So, we've got a trap here. It's basically a box, and then I'm going to fill it with egg boxes. So, this just gives moths something to grip onto and then also lots of nice dark nooks and crannies. So, you often find them in the bottom of the egg boxes. Gives them somewhere to hide from the light. And then we pop the light on top. And we know it's a good night for moths because I'm in an absolute swarm of midges here, and we know that moths and midges often like the same conditions. So, they like warm, humid evenings, pretty still. So, moths can be very good fliers. They can fly huge distances. Some of them can migrate, but often a lot of species aren't particularly good at flying in strong winds. So, we catch more moths when it's a still night like it is tonight. This is an actinic light. So, it has quite a lot of short wavelengths. So, moths seem to be most attracted to UV and blue light. The box here, which controls the light, has a light sensor on it. So, the light only comes on when it feels the natural light levels are dark enough for it. But as it gets darker in the evening, this light will come on, and then we'll be able to start seeing moths come into it.

It's well known that moths have been attracted to light for many years, since Roman times. Over evolutionary history, light has always been stable. The sun's risen, the sun's set, there's been no interference with that cycle. And lots of um flying animals, particularly moths and other insects, use the light to know which way's up. So they always have their back pointed to the brighter surface, which is the sky, even at night with the stars and the moon. And so by always having their back towards the light, they can keep their altitude and stop them from crashing into things and help them fly level. And when you put an artificial light in, it distorts their behaviour. So they end up trying to tilt their back towards the light, and they'll either circle around the light or they'll end up stalling or even flying upside down, which means they sort of crash around the light. And that's why we get that sort of uh trapping effect.

Moths are often seen as the brown and boring cousin of butterflies, but really, they're pretty interesting, and they can tell us a lot. There are about two and a half thousand species in the UK, so that vastly outnumbers our 60 species of butterfly. They live in all sorts of habitats. They have a huge range of life histories. So you'll have species which feed on all sorts of different plants. Some that are really generalist and some that need a very specific plant in a very specific habitat to survive. A very important species in food webs. So both as adults and as caterpillars. So they're food for bats and lots of birds. So they're really vital for spotting lots of those species that we know in the food webs.

Moths are also important pollinators. So, we don't see that often because they're mostly active at night. But in the same way that bees pollinate flowers, by going to them for nectar and transporting the pollen between flowers, moths do the same thing. And part of the reason we trap is to get the records. So, we keep a note of what we catch in the morning. The records all go into a national database, which is used to create atlases of moth. So, the distribution across the country and see how that's changing. And it is changing at the moment. We're seeing with climate change, we're seeing species that were previously restricted to the south. They're expanding their distribution up into Scotland and further north. And we're seeing species that like the sort of cooler, damper climes of Scotland are being restricted in their distribution as it's getting warmer. We had a good catch last night. We got about 20 species and probably upwards of 50 moths. So, that's a great catch. It was obviously good conditions. It's great to be able to do this kind of work out here. It tells us that the habitats are in good condition and that we've got good populations here, which is great.

Thanks to the players of the People's Post Code Lottery for supporting the National Trust for Scotland's nature conservation work.

Two species of moths, which haven’t been spotted at Grey Mare’s Tail in over 30 years, reappeared over the summer.

A recent moth trapping session at Grey Mare’s Tail Nature Reserve in Dumfries & Galloway discovered a host of furry flying visitors, including the Anomalous and Autumnal Rustic species, which hadn't been recorded at the reserve since 1993.

Alongside the Anomalous and Autumnal Rustic, our Seasonal Ranger and moth specialist, Ishbel Hayes, also found four new species not previously recorded at the Tail, including the Broad-bordered Yellow Underwing, Flounced Rustic, Pale Eggar and Mouse Moth. The moth trap that was set in August found a total of 119 individuals from 22 species of moths, representing a bumper summer for the insect at the reserve despite the overall population declines and last year’s cool, wet summer.

Woman kneels in a woodland beside a brightly lit moth trap.

Seasonal Ranger and moth specialist Ishbel Hayes carried out a moth trapping session in August

Ishbel, whose role is supported by funding raised by players of People’s Postcode Lottery, said: ’Moths are often thought of as the brown and boring cousins of butterflies, and despite our high numbers at the Tail this year, sadly, they are dwindling in numbers in general. There was a 30% drop in the abundance of the insects over the last 50 years, with two-thirds of common species found to be in decline.

’We have over 2,500 different species of moths in the UK, which is vast compared to 59 species of butterflies. What many people don’t realise is that moths are an important pollinator, helping to keep our food chains going in a similar fashion to bees, where they help pollinate flowers by transferring pollen between plants after feeding on their nectar. Some have argued that they are more efficient pollinators than bees because short summer nights limit their active hours, so it’s important we help protect them for the future. They are a key food source for many species of birds and bats, as both adults and caterpillars, so they are vital to the overall biodiversity of our ecosystems.’

A woman holds an egg carton that contains Ear Moth aggregate moths that were trapped overnight.

Ishbel Hayes identifies moths caught in a moth trap overnight, including Ear Moth aggregate

Ishbel continued: ’We carry out moth trapping at the reserve to observe the health of the moth populations and our habitats, with the data recorded added to national databases. These are used to develop moth atlases that show the distribution of different species across the UK, which help to identify trends for the insects over time.

’As a result of climate change, we are seeing moth distributions changing, with those previously only found in the warmer climes of the south of England expanding further north, and those which prefer the damper, cooler Scottish weather restricted to fewer areas.

’Moths are being impacted by several environmental factors, including habitat loss and light pollution. We are also starting to see moths emerging earlier in the year, causing desynchronisation with food sources and causing knock-on impacts for feeding birds and bats. Our work is vital to help maintain healthy habitats for the moths and other insect species in our care. It is thanks to the continued generosity of our members and supporters, including players of People’s Postcode Lottery, that we’re able to continue our vital work to protect Scotland’s natural heritage at these special places for everyone to enjoy, now and into the future.’

Close up picture of an Autumnal Rustic moth, which is a white, silver colour with black markings on its wings.

The Autumnal Rustic is one of the moths found at Grey Mare’s Tail for the first time in three decades.

Players of People’s Postcode Lottery have supported the Trust's Love Our Nature project since 2022, which benefited from £900k last year. Further funding will support nature conservation work across a variety of different habitats, including coastal and marine areas, peatlands, wetlands, woodland, and the eight National Nature Reserves cared for by the Trust.

Head of Charities at People’s Postcode Lottery, Laura Chow, said: ’Players of People’s Postcode Lottery are helping the National Trust for Scotland protect important moths and insects across some of the country’s most treasured nature reserves. Through ongoing monitoring and data gathering, the Trust's work is enhancing biodiversity and protecting the precious species that call these habitats home.’

Moths in decline figures are based on research published in the State of Britain’s Larger Moths in 2021.