Unique insects aren’t in the Burren for the scenery – but add another resplendent layer to an astonishing part of Ireland

On your honkers – or better still, your hands and knees – is sometimes the only way to feel and understand a landscape. As a kid, I had seen the cratered expanse of the Burren in Clare from a distance; the silver blue-grey slabs of limestone, whose contours swirl like thickly whipped ice-cream, appeared lifeless, hard and empty.
But then, as a young zoology student, I had the chance to go on a field trip and found myself lying on the warm, pockmarked blocks of sedimentary rock while reaching my arm down the dark, damp crevices as if plunging my hand into the bowels of the earth. I was eye-level with ferns and flowering plants which were growing out of the fissures, and for the first time, I understood that this was no uniform rocky landscape; instead, up close, the multitude of micro-habitats above and below ground created spaces for life everywhere.
The story of how the Burren formed has always been mind-bending; each time I think of it my brain seems to resist the simple facts – unable, perhaps, to fathom both the timescale and imagine how one landscape can radically change into another. The digested story is this: 350 million years ago, the Burren was submerged under warm tropical crystal-clear water where colourful marine species such as corals, starfish-like crinoids and molluscs lived. Upon death, their calcium-rich skeletons drifted down to the seafloor, and over 20 million years the remains of the dead compressed and solidified into limestone rock.
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And then, millions of years later, enormous tectonic forces lifted the bedrock above sea level. Over time, glaciers scoured the surface and exposed the rock, and acidic rainwater ate away at the calcium. What was left is what we see today: a fossil-rich rocky landscape full of sinkholes, caves and underground rivers, the hard surface made soft to the eye by the diversity of plants that inhabit the joints and fractures.
I was thinking of this field trip while reading Fiona Sampson’s Limestone Country, in which she writes evocatively of four limestone landscapes across Europe – Skocjan in Slovenia, Coleshill in England, Le Chambon in France, and Jerusalem. The book is a self-described love affair with the rock “which time and water make out of bones and shells”, and she memorably describes limestone as “the cannibal earth reconsuming her own”.
With plants growing in the rocky gaps come insects, and for entomologists, the Burren is a Mecca. The latest edition of the Entomologist’s Record and Journal of Variation, published by the Amateur Entomologists’ Society and dedicated to the memory of Irish naturalist Charles Nelson, who died earlier this year, reveals that the Burren is today home to 65 per cent of all known species of moths and butterflies in the country.
Until the mid-20th century, little was known about insects in the Burren, until 1949, when an ex-army officer and poultry farmer called W Stuart Wright from Lurgan in Armagh spotted a reasonably large and striking hairy lime-green moth resting on bracken somewhere west of Ballyvaughan. Named the Burren Green, it’s a remarkable and beautiful moth (Wright later said its discovery was “the pride of my collection”), and it put the spotlight on this corner of the west of Ireland. Insect lovers flocked to the area to see what else they could find. A Burren Fund was established with money from the Royal Irish Academy, among others. By the early 1960s, multiple ecological surveys and research projects were under way.
A comprehensive checklist of moths and butterflies compiled in 1967 – the last until this year’s publication in the Entomologist’s Record – listed 699 species. Today, that number is 1,002, an increase due to the development of the moth trap and a surge in the number of people actively looking. It includes the bark-coloured Irish Annulet, which feeds on buckthorn, discovered in 1991 near Lough Bunny. Only two moth species haven’t been seen in the Burren since 1949: the unmistakable orange-auburn Rosy Footman, whose wings are marked by a wavy dark line, rather like a spectrogram, and which hasn’t been since there since 1851, and the critically endangered Thrift Clearwing, whose larva lives on the Thrift plant. This moth has long, bristled antennae, and it was last recorded in the Black Head area in the 1930s.
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The Burren is home to 27 species of moths and butterflies found nowhere else in Ireland, along with all of our rarest butterflies and half our rarest moths. These insects aren’t there for the scenery, but because of the diversity of flowering plants which grow in the limestone. But for the rest of us, they add another resplendent layer to an astonishing part of Ireland. “This, our Burren, is beautiful beyond compare,” said the late Wexford journalist Sarah Poyntz, who spent 27 years writing about nature in the area. No truer words.
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