BUTTERFLY EFFECT
With movements to create butterfly-friendly gardens and meadows across the country, there is hope that several species will thrive once more, discovers
Wildlife correspondent Cal Flyn shares some tips on how to encourage butterflies into your garden
The year of 2020 may have been gruelling – with many of us facing illness, financial worries and long periods of confinement – but, if nothing else, it has been an excellent year for butterfly spotting. Thanks to an early heatwave, midsummer butterflies appeared up to a month ahead of schedule, and in huge quantity: the Big Butterfly Count, Britain’s annual butterfly census, is still crunching its numbers, but it’s expected to conclude that 2020 has been the best butterfly summer for a quarter of a century – a great relief for lepidopterists, given that three quarters of butterfly species in the UK are believed to be in decline.
Those of us who spent lockdown treading the paths close to our houses will already be well aware of the butterfly’s ubiquity this year: those flurries of soft wings rising from the long grass, that somersaulting flight of a butterfly soaring by, has been a regular sight over the last few months.
It’s great news for Anthony McCluskey, project officer for Butterfly Conservation Scotland. ‘Peacocks, Orange Tips and Small Tortoiseshells have had a very good time this year,’ he tells me. I can certainly attest to the latter, having seen Small Tortoiseshells in droves near my home in Orkney. Those unmistakable orange, yellow and black wings edged with periwinkle frills. Three good years in a row, as we have experienced recently, is a big boost for a species whose population has fallen by nearly 70% over the last decade.
Also on the increase, says Anthony, are less well-known species like the Small Skipper and the Speckled Wood. Both are beneficiaries of climate change, at least in a Scottish context, expanding their territory northwards as temperatures rise. The Small Skipper has saffron-orange wings with darker edging, and can usually be found in rough grassland, sand dunes and road verges. ‘Thanks to our volunteers, we have been recording their spread. They used to only be found in the Borders, but they’ve been coming north up the coast,’ Anthony tells me. The Small Skipper first arrived three or four years ago in Edinburgh, and now can be found as far north as Fife.
The Speckled Wood – whose mahogany wings are dappled with gold and blackened eyes – has also been gaining ground, having previously been found only in a few of the country’s mildest micro-climates. Bucking the overall trend, its numbers have risen by more than 80% in four decades, and continues its land grab apace.
It’s not all good news, however. ‘One butterfly, called the Small Copper, seems to have declined by 40% to 50%, particularly in urban areas. It used to be
very common and widespread.’ Anthony is appealing for late sightings of the butterfly, which can usually be expected to fly until late September in all parts of the country. ‘It should be almost everywhere,’ he says. The easiest way for members of the public to record butterfly sightings is through the iRecord Butterflies app (which is free and available for iOS and Android phones), which also offers a useful identification guide and distribution maps.
Urban areas have been a focal point for Butterfly Conservation Scotland, which has been working to create butterflyfriendly meadows in sites including Glasgow, Edinburgh, Hamilton, Blantyre, and Lennoxtown. The recent fashion for brightlycoloured wildflower verges and borders has been a major improvement, ecologically speaking, upon more traditional flower beds, says Anthony: bees and hoverflies love them. However, many of the commercially sold ‘wildflower’ seed mixes include only non-native or annual plants, which do not benefit butterflies in the same way.
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We use over 20 species in our feed mix to support the caterpillar stage
A butterfly-friendly meadow, he explains, ‘is one that has perennial wildflowers native to this country. Butterflies and moths rely upon certain food plants. We use over 20 species in our feed mix to support the larval – caterpillar – stage, which then creates a higher number of adults. Caterpillars can’t feed on most non-native plants. We’ve been trying to work with local authorities to keep this approach in mind.’
It also presents an opportunity for butterfly fans to get involved, either by creating a butterfly-friendly garden at home, or by helping out on Butterfly Conservation Scotland meadows, which need year-round attention. ‘This autumn and winter we will be sowing more wildflowers, planting and managing the grassland by taking hay from the meadows and sowing more seeds.’ (If this sounds like something you’d like to get involved with, get in touch with Anthony at amccluskey@ butterfly-conservation.org).
This year, the early heatwave was so intense in places that it interfered with certain caterpillars’ feedstuffs. ‘Butterflies
that depend upon grasses were affected by drought. So we’ve been seeing low numbers of the brown butterflies, including the Grayling, which has been doing very poorly at Holyrood Park – one of the places we monitor – as the grass didn’t grow,’ says Anthony.
Holyrood is also synonymous with one of Scotland’s most threatened butterflies, the Northern Brown Argus, currently the focus of one of Butterfly Conservation Scotland’s special projects. ‘It was discovered in Holyrood Park around the year 1700, the first in the world. It became locally extinct, but was then rediscovered in the park around a decade ago,’ explains Anthony. The Scottish Borders is now considered the most important region for the Northern Brown Argus butterfly in the UK.
Its caterpillars eat only the leaves of the common rock-rose – a plant that is not, in fact, a rose, but a low-growing evergreen shrub with lurid yellow flowers. ‘It grows in rocky, exposed sunny sites in species-rich grassland. We plant the common rock-rose, but also manage the gorse, which often encroaches on sites like this, shading out the wildflowers and herbs.’
Ongoing surveys in the Scottish Borders have identified 92 colonies, many of them clustered around Hawick and Galashiels, or along the eastern coastline near Eyemouth.
One delight we missed out on this year was the annual influx of Painted Ladies – when hundreds of thousands, even millions of the pretty colourspeckled butterflies arrive from overseas during their spring migration from tropical Africa to the Arctic Circle. This massive expedition is truly a journey of a lifetime for the Painted Lady – or, more accurately, several lifetimes, as no single butterfly setting off from Africa will live to see the far north. Indeed, it can take up to six generations between departure and arrival.
In 2019 we had a bumper year – a once-in-a-decade natural wonder, when a Painted Lady seemed to sit on every flowerhead one saw – but this year they have been unexpectedly absent, with only 157 being sighted in Scotland during the 2020 Big Butterfly Count. ‘This year we had almost none,’ says Anthony. ‘We don’t know where they are – we assume somewhere in continental Europe.’
But we can’t have everything. Enjoy butterfly season while it lasts: as the colder weather closes in once more, some species will migrate southwards while others will find a dark nook to hibernate.
Most Scottish species spend the winter as caterpillars, but look out for the five butterflies that overwinter as adults (the yellow Brimstone, the leopard-spotted Comma, the violet-eyed Peacock, the Red Admiral and the Small Tortoiseshell), who will tuck themselves up in a quiet spot to sleep the dark nights away, and occasionally wake on mild winter days to stretch their wings.
In this way, every day might be a butterfly day.