black & yellow striped caterpillars, brown and orange butterflies, Bryn Euryn Nature Reserve, butterflies in long grass, day-flying moths, late summer wildflowers
Just a few short short weeks ago things weren’t looking too hopeful for our summer butterflies; the cold, damp start to the season had kept their numbers low and every sighting of any species was gratefully received and shared on social media. With many species already in decline, the predictions for the success of this year’s summer broods were edging on pessimistic and on many days, when out on walks I didn’t see a single one. Half-way through this month, a guided ‘Butterfly Walk’ was scheduled by a friend that regularly records the butterfly transect around Bryn Euryn, the limestone hill in North Wales which is at the centre of my ‘patch’. In preparation he’d done a recce the day before and his sightings were so few that he put out a warning that evening suggesting people may want to postpone the event and try again in a week or two! No-one cancelled, probably as most of are of an age where we’re not constantly checking our emails or social media sites, and about 20 of us gathered as arranged. Perhaps we were also a little giddy with the excitement of our very recent release from some of our Covid 19 restrictions (Wales has been a tad more cautious than England), and this was the first time we’d been allowed to meet up outside of Zoom since lockdown began. So in the spirit of ‘mad dogs and English/Welsh men and women’, we set off on this boiling hot Sunday afternoon (the beginning of the heatwave) to walk up to the top of the hill, 430 feet (131m) closer to the sun in the hope there’d be at least a few butterflies putting on a show for us.
Of course it was well worth the effort, or I wouldn’t be mentioning it; in the space of 24 hours the butterfly species count had magically rocketed from practically zero to most of those we’d expect to see here on a good day at this time of year, plus day-flying moths The count for each species wasn’t high, but the majority of those we saw were fresh and all were highly mobile and in a group that size, numbers of pairs of eyes meant we didn’t miss seeing much. But the best part was watching the effect these particular insects have on people of all ages; some excitedly enjoyed the first sightings of rapid-flying Dark Green Fritillaries while others crouched down around a plant to witness the mating of a pair of Small Skippers. All captivated by the fluttering of wings and for a few magical moments, completely absorbed and transported into another dimension. Butterfly chasing should definitely be put on prescription!
Although I’d thoroughly enjoyed the company and butterfly sightings seen by the group, I’d missed photographing the fabulous-but-flighty Fritillaries, so as the hot weather seemed to be holding, I wanted to go around again at my usual meandering speed and a couple of days later I set off to see if I could fill in the gaps. This time I wandered up through the woods where the paths and trails are shaded and it’s a pleasant degree or two cooler than out on the open hillside, which surely has to be one of the best reasons for planting more trees in a warming climate.
Now the tree canopy is more or less closed and limiting the light reaching the ground, flowering plants are scarce and as the earth dries out any that aren’t designed to cope quickly wilt. Built to withstand such conditions, one exception is Wood Sage, whose flowers seem particularly suited to Common Carder bees. Nipplewort, an annual plant with tiny yellow flowers and slim wiry stems always seems to find a few agreeable spots along these paths too.
As always I stopped at the fence on the woodland boundary to look out over the meadow on the other side. The long grass was cut on a mild, sunny day back in January this year, which at the time I remember thinking seemed like a strange time to be doing that, but it doesn’t seem to have mattered as now it’s grown tall again and I could see there’s also Hogweed and Ragwort in flower and it’s full of Knapweed in bud. I could also see it was alive with butterflies – mostly Meadow Browns as far as I could see, which was a good sign there would be more to see in more accessible places higher up. There were clearly other insects about too – my photo was ‘bombed’ by what could be a wasp or maybe a hoverfly!
Stepping onto the Woodland Trail that circuits the Nature Reserve it was hot – too hot now for insects such as hoverflies that would all be hiding away under leaves or on tree branches. Birds are mostly beginning a ‘time-out’ in which to rest after a busy breeding season and to moult their old feathers and grow new ones, so it was very quiet. The total lack of a breeze was even keeping down the ever-present traffic noise from the valley below.
Leaving the woods behind I joined the Summit Trail, more or less at the point where we’d begun the butterfly transect on Sunday. The small field here used to have a good patch of long flowery grass at this lower end, but perhaps due to more trampling and changes in the weather patterns, it’s not as good as it used to be for butterflies. Today there were a Small Skipper and a few Meadow Browns flitting about in the grass, but far more of the latter around the field edges where there is scrubby vegetation with low bushes of bramble and gorse. I counted to roughly 30, all busily chasing about low in the grass and around the brambles, with none settling for even a quick snap. The wildflowers are a bit sparse too, some Lady’s Bedstraw, a scattering of Rockrose, a few clumps of Keeled Garlic and the odd Harebell were all there was to see. The huge spread of Hemp Agrimony is just beginning to open its flowers and on the opposite side of the field the Burnet Roses have a good crop of hips; red now, but they’ll ultimately ripen to black. One of my favourite sights now are the feathery globes of Goat’s-beard that stand like little beacons in the shorter grass.
From the open field the trail goes up through the woods again, so there’s another short break from the heat, although the slope is steep. At the top is the clifftop with the long grass and scrubby vegetation pictured at the beginning of the post, and it was here that during the last two days, butterfly numbers had increased the most dramatically. Where there had been maybe 20 or so on Sunday, now there were more than I could have counted of Meadow Browns, a good number of Gatekeepers, lots of little Small Heaths, several Small Skippers, one or two Brown Argus, a Grayling and possibly even a Dingy Skipper. Standing out amongst the crowd of brown and orange butterflies were dramatic red and black 6-spot Burnet moths. All of these species are dependent on tall grasses as food plants for their caterpillars and as adults they take nectar from flowers, so where there’s a good area of long grass with wildflowers in it, they don’t need to move far.
The hot sunshine had coaxed more flowers into bloom too, particularly the blue-lilac Scabious, which is a favourite of butterflies and of many other species of insects too.
On a cooler day I would have lingered longer around this one spot and doubtless found even more than I did, but the heat out on the open hillside was intense, and if I was to find Fritillaries I had still to get up to the summit and down the other side of the hill. When I first began exploring this hillside, back in 2012, the management of it was quite different; the long grass would have been kept shorter and Ragwort considered a noxious weed and kept at bay. Gradually attitudes have changed and over the years the plant has spread considerably and a result, as well as providing important nectar and pollen for invertebrates, the numbers of plants supporting the unmistakeable black and yellow striped caterpillars of Cinnabar moths has also increased; some plants had several, others one or two.
Going down the other side of the hill it was Burnet moths that dominated the airways, flying low in, over and about the grassy slope. Many would have been newly emerged from their alien-pod like yellow which are frequently seen attached to grass and other plant stems. Often there is a mass emergence, with males emerging first. They then sit above the cocoon of a female and wait for her to emerge, pouncing on her to mate before she’s barely had time to draw her first breath of fresh air.
Amongst the grass on this side of the hill you can find some of this site’s loveliest wildflowers, Common Spotted Orchids; most are at the end of their flowering now, but while following one of only two Dark Green Fritillaries I saw today I found a few fairly fresh ones. There was some Dropwort too, the dry limestone grassland relative of the similar-looking moisture-loving Meadowsweet.
On the other side of the trail, where the hillside is left much to its own devices a lovely pink-purple haze of Rosebay Willowherb stands out against a backdrop of trees.
Despite my best efforts, I didn’t get my photo of a Dark Green Fritillary, but it was too hot to chase about, so I sat on the grass for a short while and enjoyed watching those I saw; they are impressive – and very fast on the wing! Luckily I have a stack of photographs taken on other occasions in this exact spot, so here’s one I made earlier.
As so often happens, there were compensations; close to where I’d stopped a Brown Argus landed on Ragwort and another fresh Gatekeeper on nearby Hemp Agrimony.
Then as I was about to turn and head back home, my favourite of all the summer butterflies, a perfectly beautiful little Small Copper landed first on a stone at the edge of the trail then flew up to a nearby Ragwort; my first sighting of one this year and a perfect note to finish on.