August 2018 has returned to us the more typical Irish summer conditions but the heat earlier in the summer means that there are high numbers of butterflies flying now, which developed quickly in the warm weather that prevailed during the immature life stages. One very important butterfly flying now and during September is the Wall Brown, a butterfly that has seen a marked decline in distribution and range in Ireland since the mid-1980’s. Before the mid-1980’s it was found throughout Ireland in the general countryside but is now mainly restricted to the most free-draining, driest, thinly-vegetated areas such as sand and gravel quarries (probably also found in dimension stone and aggregate stone quarries ), sand dunes, dry coastal heaths, rocky areas such as limestone pavement, dry limestone and acid grassland and the driest areas of cutover bogs. It is absent from many areas inland that it occupied in the past, such as along tracks worn to bare earth on farmland, dry hedge banks and lanes and at the edge of country roads edged by stone walls. It is feared extinct in Northern Ireland where it was last recorded at a coastal site in County Down in 2015. It remains numerous in County Donegal, where, according to excellent recorders, there has been no decline.
The Wall Brown may return to the broader countryside as it is a mobile butterfly and can fly great distances when the urge to move exists. We include two photographs of this lovely butterfly. It is often seen in low numbers but occasionally a dozen or more will be seen concentrated in an area of suitable habitat. It is a sun-loving butterfly. Males are eye-catching. If you see one, he will usually be seen flying low ahead of you, landing periodically to bask against bare surfaces. It holds its wings in a shallow V as it flies. After flying along a track or a stone wall for many metres, it will often turn and fly back, pausing to bask briefly before resuming its patrol. When direct sunlight is dimmed by cloud, the butterfly lands and basks briefly before closing its wings. It is only then that a close approach is usually possible. The female looks similar but is paler overall and does not have the dark brown diagonal band across the upper side of the forewing. Note the presence of white-pupils on black eye-spots. The presence of eye-spots shows its membership of the Satyridae or the “Browns” (regarded by taxonomists as a subfamily of Nymphalidae which includes the fritillaries and vanessids). Other members of the subfamily Satyridae include the Meadow Brown and Speckled Wood.
The Wall Brown shows a similar decline in Britain. It is presumed extinct in Surrey, for example, a southern county that holds many sites containing apparently suitable habitats. Box Hill was one of the last Surrey sites it survived on, and the site continues to hold well-drained, sparsely vegetated grassland one associates with the butterfly. It is the mystery of its decline that adds to the alarm as we have no idea what measures are needed to help it to recover. If you see one on your walk along a country road, on your ramble through flower-rich sand dunes, a cliff walk or anywhere else please let us know, according to the details we need for a valid record; for what is needed please check our website here: https://butterflyconservation.ie/wp/records/
Biodiversity Ireland Issue 17 Spring/Summer 2018 published by the National Biodiversity Centre contains an article by Dr Tomás Murray promoting butterfly recording for the Butterfly Atlas 2021.
The article contains this bleak statistic of Ireland’s declining butterflies: “Ireland (is) identified as being in the top five countries for declines in both widespread and specialist species, out of 21 countries assessed”.
It continues: “For the 15 species where we have sufficient information, our monitoring schemes reveal that seven of those species are in decline compared to three increasing, two stable and three that are too variable to assess”.
Is it that bad?
From what I see on sites I visit regularly, and from parts of the countryside I see from time to time, there are changes in butterfly populations. Without even attempting any population monitoring, it is clear that butterfly populations have undergone significant changes. This is evident when observing the changes in land use. Habitat specialists, in particular, are unlikely to survive for long in areas where their habitats are altered or destroyed by being replaced by golf courses, built on, afforested, drained, mined, cleared, modified by application of chemical fertilisers, ploughed and re-seeded, etc. In habitats not directly altered or destroyed, butterflies can be affected by gradual changes, especially by successional changes in vegetation and by changes to adjoining land such as flooding, drainage, tree-felling or tree-planting, planting of invasive plant species (such as cotoneaster) and other alterations. Natural factors such as coastal erosion, severe in some areas, results in changes to habitats and sometimes to the destruction of high-value conservation land.
It is easy to be pessimistic for the future of our butterfly populations, especially about our habitat specialists. My recent visit to the area south of Lough Corrib, County Galway engendered much despondency in me. This area, north of the N59 towards Lough Corrib between Moycullen and Oughterard contains a variety of habitats, especially bog, calcareous grassland, limestone pavement, scrub and woodland. A number of important habitat specialists have been recorded from the area. These include the Brimstone, Dingy Skipper, Brown Hairstreak, Small Blue, Pearl-bordered Fritillary (in the 1980’s), Marsh Fritillary and Large Heath.
On my visit, I encountered many new, often out-sized individual houses (with boundaries starkly proclaimed by laurel and Leylandii hedging) imposed on what appeared to have once been great habitat. I observed peat being gouged out of the bogs, parts of which have been converted to fairly unproductive agricultural grassland. Rough walls, composed of natural limestone pavement and boulders ripped from rare karst habitats are frequent in the area. It appears that few areas of untouched limestone habitat remain. In one area I examined off the local road from the N59 to Carrowmoreknock, bog grades into limestone grassland, limestone outcrops and scrub habitats. Flowers characteristic of grassy bog and limestone grassland almost have their petals touching. But the limestone pavement that once existed is no more, the limestone slabs torn up to form monumental walling. The area has clearly lost some value. It is likely that Grayling and perhaps even Pearl-bordered Fritillary flew here, but no longer. However, clearing the limestone pavement appears to have rebounded on the farmer, as that area is now buried in dense scrub. Marsh Fritillary breeds on the sward where bog grades into limestone grassland, quite likely assisted by the livestock grazing taking place.
When special habitats like these are degraded or destroyed despair deepens, as the count of precious places with their associated butterflies decreases. Once limestone pavement is ripped up, there is no chance of restoration. The habitat is gone. There are species that will not survive when this damage is done. There will be no return.
Some habitats of special character are designated as Special Areas of Conservation and therefore legally protected. However, the Special Area of Conservation that lies west of Carrowmoreknock, Gortnandarragh Limestone Pavement, has been damaged by quarrying and conversion of part of the area to farmland. Protection clearly needs to be enforced! Even when sites are protected they are sometimes unmanaged leading to undesirable successional changes in the vegetation, causing habitats to deteriorate. In the circumstances outlined above, it is easy to see that habitat specialists are likely to be in decline, and why.
What about the general countryside butterflies, the ones that breed in a broad range of habitats? Even a glance at the general farmed landscape suggests evidence for declines. Many semi-natural grasslands formerly very rich in butterflies are ploughed and re-seeded with one or two grass species and heavily fertilised. Some remaining semi-natural grasslands are heavily dosed in fertiliser annually, resulting in a habitat that excludes many of the food plants butterflies and moths need. Some semi-natural grassland has been ploughed up and planted with non-native conifers. Hedges and hedge banks are severely cut or even removed. Ponds and wet areas are drained or farming ceases, and formerly good habitats that were well managed by rough cattle grazing deteriorate. The inappropriate management of our public spaces, such as parks and canal banks where vegetation is cut when butterflies are feeding and breeding are further examples of drivers of decline. Given these grim circumstances, why are some butterflies doing well?
Firstly, let consider the species that are showing increases in population size (abundance) and in distribution (area occupied). Based on my observations, the resident species that I believe are showing increases in population size and distribution are Cryptic Wood White, Brimstone, Holly Blue, Peacock, Comma and Silver-washed Fritillary. The Speckled Wood is likely to be stable or possibly increasing. While the article quoted above mentions that three species are increasing, I believe that six species are increasing. Interestingly, all of these are found in woodland and woodland edges but other habitats are used by some of these butterflies. Wooded areas are increasing in Ireland. Some are arising from the abandonment of farming, some are planted, some existing woods are spreading and some woodland is new, developing on cutover bogs and on limestone pavement.
To take each of these butterflies in turn, the Brimstone is benefitting from the development of its larval food plants on cutover bogs. The food plants are developing in areas that used to be wet raised bogs and the spread of the butterfly into these areas suggests a genuine increase in distribution. The development of scrub containing the Brimstone’s food plants on eskers, rough hillsides, abandoned quarries and on limestone pavement is also helping the butterfly.
The reasons for the Holly Blue’s increase are harder to assess. It was, before the 1990’s, largely restricted to old woodland near the coast in Ireland but has spread inland to hedges, wooded lanes and even rural gardens, although it was found in large urban gardens before the period of expansion. The increase in woodland is likely to be a factor but a warming climate is likely to be more significant. In Britain it is very rare or perhaps absent from Scotland and rare in Northern England, reflecting its sensitivity to cooler climates.
The Peacock has probably benefited from the increase in warmth too, suggested by its increase in a cooler Northern Ireland which has been ongoing since the mid-1990’s. It is still found in smaller numbers there than further south. The increase in nitrate fertiliser usage over the past few decades benefits its larval food plant, the Stinging Nettle, which may be more vigorous, numerous and nutritious as a result. The Comma, a recent and continuing colonist, is likely to be benefiting from the same factors as the Peacock. There may be additional factors behind the Comma’s rise. It may have developed a preference for use of the abundant Stinging Nettle as a larval food plant, rather than relying on plants such as Hop, which is rare in Ireland.
The Silver-washed Fritillary is a woodland butterfly, breeding on violets growing in well-lit woods. When plantation forestry is cut down, the non-crop tree species are frequently left to grow among newly sown sapling trees, ensuring that woods are not clear-felled and that some shade remains. The light admitted after decades of darkness may make some of these areas suitable for the Silver-washed Fritillary especially a few years after re-planting. Edging conifer plantations with native trees may create habitat, even if this is simply a thin belt of woodland adjoining the arboreal slums of mature, modern non-native coniferous plantations. Even when plantations do not have a cosmetic band of native broadleaf trees added, a scattering of willow and birch seed often germinates along the edges, with Silver-washed Fritillary habitat developing over the following two decades. The growth of tall scrub and trees on abandoned farmland creates habitat too. The butterfly is turning up in the new semi-natural woods colonising the cutover bogs and tall scrub on limestone pavement. Some of these areas now boast large and extensive populations. In addition, some conifer plantation woodland planted on bogs develops poorly, with some trees dying after 20-30 years, leaving gaps that open up the ground to light and suitable vegetation. The dark cloud cast by the demise of Large Heath’s wet bog habitat is the Silver-washed Fritillary’s silver lining.
The Cryptic Wood White loves to fly and breed along sunny herb-rich wood edges, so is in its element along the access tracks through woods and along the edges of new wooded areas. The fact that it looks superficially like some other white species may result in it being under-recorded, but I believe it is doing well. It even shows up in my garden!
To guess which species are in decline is depressingly easy. I will mention a few here. The Dark Green Fritillary cannot be doing well in its main habitats. Its preferred habitat, unfertilised flower-rich grassland is quite rare now outside the coasts. For the same reason, Dingy Skipper, Small Blue, Common Blue, Small Heath, Wall Brown and many other semi-natural grassland dwellers must be in trouble. There are likely to be additional reasons for the fall and fall of the Wall Brown but these are not clearly understood.
However, we need hard data. My observations do not count without robust, scientifically reliable statistics. The records being sent to Butterfly Conservation Ireland from 2017 to 2021 will be used along with records collected by Butterfly Conservation Northern Ireland and the National Biodiversity Data Centre to compile an All-Ireland Butterfly Atlas in 2021. Please send us your butterfly records. We explain how to do this here: https://butterflyconservation.ie/wp/records/
We have images of all Ireland’s butterflies here to help you identify our butterflies: https://butterflyconservation.ie/wp/gallery/
The other measures you can take concern habitat protection and habitat development. Report any damaging activity you see taking place on any protected site to the National Parks and Wildlife Service. Insist on receiving information on how your concerns are followed up. The full list of Special Areas of Conservation and Special Protection Areas are here: https://www.npws.ie/protected-sites.
The data you send us will be used to create the Atlas and to update the Ireland Butterfly Red List, due to be updated in 2020. Armed with this data, we will be able to press the state for better protection and management of our landscapes so that there will still be some wildlife-rich areas for you and your children to enjoy and for our butterflies and moths to live in.
August is a busy month on the reserve at Lullybeg. Some butterfly species are busily feeding as adults or as larvae, racing to feed up for the winter. Other species are feeding to build reserves for migration or breeding. Individual adult butterflies of some species can either over-winter as adults or breed now (Small Tortoiseshell) while other species may breed now or prepare to migrate (Red Admiral). The potential for this flexibility may depend on a range of circumstances (such when the adult emerged) and conditions (weather, the condition of the larval food plant, etc). These complications and possibilities add variety and interest, and the observer can scan for clues as to the strategy used by species that have the capacity to be flexible. These clues will be seen in the behaviour. Are the male butterflies concentrating on feeding or on establishing territories and pursuing potential mates? Are females focussing on feeding or fluttering around the larval food plants?
For an example of a butterfly that can be flexible in its approach at this time of year, let us look at the Small Copper. The second generation of this species is flying now. This elegant little butterfly is now breeding. Some of the butterfly’s offspring may, if sunlight, temperature and food plant quality are suitable, become adult butterflies this year. These will fly in late September and in October. If the conditions do not allow for a third generation of the Small Copper or are marginal, most or all of the autumn larvae will endure winter hunkered down deep in the vegetation to resume feeding when spring arrives. These will reach the adult state next May or early to mid-June. I counted eleven of these sparkling starlets on the reserve today, a good tally for a butterfly usually recorded in low single figures.
Several butterfly species have their entire population in the larval stage now. The Marsh Fritillary butterfly is strengthening its population at Lullybeg, with 31 larval nests found on the reserve so far. I watched larvae feeding today, some outside their webs, nibbling in unison at the upper epidermis of the leaves of their sole food plant, Devil’s-bit Scabious. Some larvae are in their first instar while others have moulted their skins once to reach the second instar. The larvae may need to reach a healthy weight before their final moult later in autumn when they reach the fourth instar. Some species will not survive winter unless the larva reaches a certain instar before cold weather bites. The Speckled Wood is an example of this urgency. I suspect that the Small Heath larva must also reach a certain stage before winter if it is to survive.
Some butterflies don’t have these worries. The last Dark Green Fritillaries of the season was probably the tattered trio I saw on August 3rd. Their larvae, and the larvae of its bigger cousin, the Silver-washed Fritillary, hatch after two weeks, consume the eggshell and hibernate. The larva fasts for at least seven months before seeking violets to feed on. However, the larvae do have some concerns. They must not be discovered by birds, beetles or spiders. They must hope that their mothers placed them in the best conditions for over-wintering and feeding when the time comes. For the Silver-washed Fritillary, the egg-site is a cool, shady spot on a tree trunk, often on moss or half-hidden by ivy or in a crevice in a tree trunk. The Dark Green Fritillary lays her precious egg among dense, cool grass tufts with violets close by or among the tangle of grass. The cool conditions are chosen so that the tiny unfed larva does not shrivel in the August and September heat.
Life is simple for Brimstone butterflies. Feed up. That’s all they need to do. There is no complicated multi-brood strategy for our longest-lived adult butterfly. Just get as much Common Knapweed and Devil’s-bit Scabious nectar as possible before vanishing in September or October until the sun’s heat returns in mid-March.
There is so much going on now, with vast flights of ladybirds, bees, flies, dragonflies. All are racing against summer’s diminishing hour-glass. Before the sands of summer slip through your fingers, get out and savour what’s left.
Here we are in August, a month of grandeur for the special jewels of our landscapes. Below are some butterflies found this month, all recently photographed. What a summer we continue to have!
Common Blues are seemingly everywhere, even turning up in gardens where some are breeding. Some individual Common Blues are much smaller than they should be, no doubt products of drought conditions reducing the food available to the larvae. I peered hard at a couple today, so diminutive as to suggest a Small Blue.
Small Coppers are widespread but not numerous but this is typical of this lovely creatures population dynamic. No photograph can really represent its sparkling copper upper surfaces, so here I opt for a more sombre photograph of its undersides, still elegant and interestingly distinct from British populations. British Small Coppers usually have brown rather than grey undersides with a lesser defined, more subdued reddish hindwing band than the ones that grace our flowers.
Peacocks seem to be launching a takeover attempt at the moment. I am rarely shocked at their population sizes on good sites but the swarm encountered at a special site recently left me gaping in admiration as a blur of reds, golds and purples swirled in the sunshine! Never spray your nettles, the plant it breeds on!
The Brimstone is out in numbers now in its midland haunts, dawdling for several minutes at favoured Common Knapweed blooms, oblivious to bees jostling for their share.
Small Tortoiseshells are just beginning to show up in gardens, fields, parks and wood edges now, and will build their numbers to outnumber the Peacocks. Alas, when this happens, we know autumn is upon us!
Eden translates as delight. And this is what butterflies bring, especially to our intimate outdoor spaces. They bring personal excitement because for gardeners the boundary line between indoors and the great outdoors is blurred in the garden. The garden is a personal space, especially gardens that are secluded, private, personal havens where we can be ourselves, sometimes more than it is possible to be in the house because there we must toil. We must carry out the necessary tasks in the house. In the garden, we can choose to act or not.
In a garden to act is often to create. We can create living spaces for our fellow creatures, or choose not to. Yesterday, I spoke to a friend about his front garden. He had removed rather unkempt but Small Tortoiseshell bedecked lavenders with red-flowering begonias and a house geranium. I peered for a moment to assure myself that the new plants were not plastic.
“Why did you do that?” I queried, mystified because I know that he loved watching the tortoiseshells.
“Oh, the bees kept flying into the house”.
“You won’t have any more bees, don’t worry. What you put in here will not be touched by any bee or butterfly”.
In this case, the house has extended into the garden. The garden has become tame, a place where plants are cabinet or mantelpiece ornaments. There is little interaction now between man and nature, which has been discouraged.
Today, in many areas, butterflies are being rendered homeless. In the developed landscapes of our cities and towns as well as in the more sterilized intensively managed countryside we need to provide safe havens. Create opportunities for life to fill your garden. Butterflies can make your garden their home, with a little thought and the correct choices and actions. And there is the pleasure that grows from knowing that these butterflies, free though they are, are ‘your’ butterflies. You may even get to know individual butterflies. A kink in a wing and you know that you saw this one yesterday. Some butterflies pause for minutes but some stay for days, even weeks. One Common Blue remained in my garden for nearly a month. I said good morning to him each day until his time on earth was done. I miss him still.
Some butterflies seem to want to know you. From early July to late September each year, a small number of my garden’s Small Tortoiseshells enter my house to roost during wet weather or for the night. These stay inside for days when it is cold or raining, typically perched on a wall, ceiling or curtain until sunshine returns. Then he or she finds his or her way out through an open door or window. The occasional butterfly will roost in the house every night, leaving when it warms up the following morning. The Small Tortoiseshell is, of course, a species that passes the winter as an adult butterfly, so the individuals that come indoors regularly in autumn have already decided on their winter abode. Very occasionally, the Peacock butterfly will enter your house to stay for the winter.
Everyone knows that butterflies like nectar but not all flowers have this food. Select true species, avoid cultivars. Most lavenders contain nectar, so does Buddleia davidii, Common Knapweed, Common Marjoram, Common Fleabane, Purple Loosestrife, Water Mint, Red Clover, Common Bird’s-foot-trefoil, Devil’s-bit Scabious and Wild Angelica to name a mere handful of flowers. All easy to grow, all perennials, all sure to draw in lots of butterflies if planted in sunny, sheltered terrain. A nettle patch against a sunny hedge or wall for the Vanessids (Red Admiral, Peacock, Small Tortoiseshell, Comma) to lay their eggs on and you will have the butterflies using your garden as a breeding site too. If your hedge has Common Holly, Spindle. Common Buckthorn, Alder Buckthorn among the Common Hawthorn you will be likely to attract many moths and butterflies such as the Holly Blue.
Some ecologists scoff a little at gardens, dismissing these as poor substitutes for ‘real habitats’. This misses some crucial points. Gardens can be managed to suit butterflies in ways that many wild habitats cannot be, simply because of a lack of resources. Gardens can have a greater range of habitats crammed into small spaces than wild areas usually contain. Gardens mark the immediate interface between man and nature and being personal spaces, we are much more likely to take personal responsibility for what happens there. While gardens will never be habitats for the more localised, specialised butterflies and moths unless the gardens adjoin these habitats and might be considered part of them, a large proportion of our butterfly and moth species have been recorded in gardens. The more effectively the larger garden is managed for nature, the more attractive it becomes for butterflies and moths, and other wildlife.
Some of the rarer, more habitat specialist butterflies have been recorded in Irish gardens. These include the Brimstone, Silver-washed Fritillary, Green Hairstreak and Wall Brown. The Comma, a recent arrival still spreading from the south-east has already been spotted in Irish gardens. In the past two days, July 15th and 16th, I have seen Large Whites, Small Whites, Green-veined Whites, Small Coppers (three stubborn males bitterly contesting the same perch post on a Common Knapweed), Holly Blues, a Painted Lady, Small Tortoiseshell, Peacock, Meadow Browns and Ringlets in my garden. A few weeks ago, a Common Blue peppered the Black Medic plants pushing up through gaps in my patio stones with eggs, so I hope to see her offspring in August.
Gardens offer a great way of tracking the fortunes of our butterflies, particularly the widespread species. Get involved in our garden survey; here’s how to do this:
The hot, dry weather continues as 2018 is turning out to be a memorable, once-in-a-generation summer here in Ireland and in Britain. However, the dry conditions may pose trouble for species that breed on herbs on thin soils now affected by drought and for the grass-feeders especially those that breed on grasses in open, unshaded areas on thin and well-drained soils.
It has been a bumper year for Marsh Fritillary, now finished flying for the year. The butterfly has been expanding its distribution by taking advantage of the warmth to fly beyond the often narrow confines of its sites to seek breeding ground further afield. Another butterfly that does this is our largest native butterfly, the Silver-washed Fritillary. In early July it is at the start of its flight period and fresh examples look really magnificent so get out to the woods and look along the tracks where flowering bramble occurs. The Silver-washed Fritillary is unlikely to be missed if present. The large size, dashing yet graceful flight and deep orange upper sides marked with black bars (male only) and black spots (both sexes) make it a striking butterfly.
Avoid confusion with its slightly smaller but even faster-flying relative, the Dark Green Fritillary. The males of both species look quite similar on their upper surfaces but the undersides differ more clearly. The Silver-washed Fritillary lives up to its name by having washed silver bands on a greenish hind-wing, while silver spots on a greenish background indicate a Dark Green Fritillary. Each species preferred habitat is often different, with Dark Green Fritillary preferring more open, grassy sites but the Dark Green Fritillary may appear in large clearings in woodland and along some wood edges where the Silver-washed Fritillary flies.
The first generation of Small Tortoiseshells is flying, but most of these will not fly for long. The majority will remain on nettle beds, breeding to produce a long-lived second brood most of which will pass the winter as adult butterflies. A small number of first generation Small Tortoiseshells will not breed this year but will over-winter together with the second generation butterflies. However, some second-generation adults may breed this year to make a third brood, especially if weather conditions allow. The result of delayed breeding is that up to three generations of Small Tortoiseshells may be spending the winter as adult butterflies. The majority of over-wintering Small Tortoiseshells will be second generation adults that emerged as adults towards the end of August and during September.
Green-veined Whites will build their numbers to peak later in July, while Small Skipper and Essex Skipper butterflies are on the wing now, the latter in County Wexford where good numbers have already been seen. The new generation of Brimstones is beginning to emerge and unsurprisingly given the heat it is appearing earlier this year. Earlier emergence may mean it is active for a longer time and this will probably result in higher numbers being predated before it retires to scrub and woods to pass the winter as an adult butterfly.
Less evident but no less interesting are the larvae present now. Peacock larvae are finishing their growth and the Small Blue larvae are departing their disintegrating Kidney Vetch flowers to seek sanctuary in the substrate below. They can be seen now on good sites feeding openly on the seed on the now flimsy inflorescence. Some will be seen on stalks, heading downwards. These larvae will pass the next eight or nine months as fully-fed larvae. These will pupate from April to fly in May and June. Timing is everything for the larvae; they need to be full-grown by the time the food plant’s seed (the part of the plant the larva feeds on) falls to the soil. If not fully-fed by then, it is likely to starve. Some have probably starved already, as many Kidney Vetch plants on sand dunes have expired in the arid, rainless weeks. Expect less Small Blues next year where the plants have shrivelled.
Now follows a butterfly seen only by the fortunate or extremely dedicated searcher. The Purple Hairstreak is a tree-top dweller flying now in oak woods or woods containing oaks. However, it is very limited in its known distribution in Ireland because of the scarcity of oak woodland and woodland with good stands of oaks. Binoculars are the usual method of discerning it high up in the leafy oak tops, spinning in the sunlight in a delicious combination of purple and silver. The oak woods in County Wicklow are probably where the highest populations occur but the oak woods in Killarney National Park are reputed for its Purple Hairstreak numbers. The oaks adjacent to the American Embassador’s residence in the Pheonix Park, Dublin also has the butterfly in very good numbers.
This year Ringlets are superabundant in their favoured habitats but a concern exists for the numbers expected next year. The larvae feed on lush grasses growing in areas where some shade exists. The heat and drought, if it continues for another few weeks, may lead to a deterioration in its grasses, but these conditions are perhaps even more likely to reduce the ranks of next year’s Meadow Browns, which prefer grasses growing in open conditions bearing the full desiccating impact of hot dry weather.
However, these common butterflies will bounce back in the following seasons given the return of rain which will renew butterfly food plants. But for now, just enjoy July 2018.
This very well-attended event began against the backdrop of doubtful weather. After searing heat on Friday and Saturday, Sunday was cool, overcast and windy, not a good sign for a butterfly outing. A consoling thought was my retention of three lovely specimens caught the previous day to show at the event.
But shortly after the meeting time of 2pm, the cloud thinned and the sun shone kindly, providing a comfortable heat. A Silver-washed Fritillary, Dark Green Fritillary and a micro moth Pyrausta purpuralis were shown to great interest and appreciation from everyone there, and the fritillaries, being recent emergents, looked especially lovely.
Posing nicely for photographs, all three took to the air and off we went. The plan for the walk involved walking two adjoining but distinct habitats. The first area is mainly shattered limestone pavement with scattered scrub. This area was very disappointing. The thin soils here hold little moisture regardless of the weather conditions but the persistent heat and lack of precipitation has resulted in a starkly parched limestone grassland. The ground vegetation is largely a withered grey and straw colour, and butterflies and moths appear to have deserted the limestone. Even violet plants in semi-shade, used by the Pearl-bordered Fritillary were seen to be in the early stages of desiccation. At this stage of the summer, we could expect Common Blue, Dark Green Fritillary, Grayling, Small Heath among others here but only about five individual butterflies were seen on the limestone.
A change of scene was needed. We walked to the adjoining site which consists of deeper soil with tall grassland and scattered limestone pavement. Our luck changed with Common Blue, Small Tortoiseshell, Dark Green Fritillary, Grayling, Meadow Brown, Ringlet and Small Heath netted and shown. Marsh Fritillary eggs laid on the underside of a Devil’s-bit Scabious leaf were shown. This butterfly has finished flying and is succeeded by its larger cousin, the Dark Green Fritillary which has two large communal roosts on the site. However, a sobering reminder of life’s ephemeral beauty was afforded by the discovery of a killing ground containing the dismembered remains of dozens of the Dark Green Fritillary, as well as a Four-spotted Chaser dragonfly. A keen-eyed predator may have found the roost and if so, is exploiting this larder. It is the first time I have witnessed this concentration of dead specimens. The sight of the colourful wings arbitrarily adorning grey limestone reminds one of the final line of the poem Butterflies (by Rosita Boland): “Gaudy and ephemeral”.
One creature that appears safe from the unknown but probable avian predator is a fully-fed Narrow-bordered Bee Hawk-moth larva, which was found barreling over limestone on its way to pupate.
On a cheery note, the female Common Blues present were the blue mariscolore form, one of our loveliest butterfly sights. This occurs usually in the north and west and its occurrence in these areas may be an ecological response to a generally cooler, wetter climate. Further east where rainfall is lower the females are more inclined to have brown upper wings but in Clare blue is more prevalent.
We watched a Grayling heat up on limestone, a Small Heath patrol a patch he was compelled to share with Ringlets. We wondered would there be as many specimens of the grass-feeding butterflies here next year if the current drought continued. We will not say this too loudly, but it needs to rain!
Thanks to all who made the event so pleasurable, especially Burrenbeo Trust and to the local farmers in the area for allowing us to walk these beautiful areas.
The events were attended by Butterfly Conservation Ireland and Belfast Naturalists’ Field Club. The moth morning led by Philip Strickland was held at Lullymore Heritage Park followed by the butterfly walk led by Jesmond Harding which took place in Lullymore West and Lullybeg.
The previous night was dry, calm and warm, a perfect combination for moths. The five traps held good catches, especially the larger Robinson traps. The full species list is awaited, but highlights include Gold Swift, Goat Moth, Northern Eggar, Pebble Hook-tip, Grass Emerald, Large Emerald, Birch Mocha, Lilac Beauty, Barred Red, Waved Carpet (a scarce species), Northern Spinach, Eyed Hawk-moth, Poplar Hawk-moth, Elephant Hawk-moth, Beautiful Snout, Scarce Silver Y and Burnished Brass.
A great many photographs were taken by field club members who were very interested by the enormous range of the moths’ colours, patterns and shapes. Moth study is fascinating, even if one never gets beyond enjoying their physical appearance, especially the painstaking intricacies of their patterns.
The moths were released after the photos and their day-flying relatives were examined. A lovely female Meadow Brown showing delightfully intense orange fore-wing markings posed very nicely for the photographers. Often seen as a less glamorous species, this was certainly an arresting beauty. Ringlets bobbed along the wayside grasses following us as we made a stroll to the rich grasslands at Lullymore. Marsh Fritillary eggs were seen on the underside of a large leaf of the food plant, Devil’s-bit Scabious. These have turned purple-brown, having been laid about a week ago. Their parents are no longer alive, but have left us with the next generation in egg form.
Common Blues fluttered their shining, tinfoil blue wings above still yellow Common Bird’s-foot-trefoil flowers, while a myriad of marauding dragonflies made their direct linear flights and hairpin-bend turns. One snatched a Birch Mocha which it dispatched immediately. The species seen included Four-spotted Chaser, Black-tailed Skimmer, Brown Hawker and a single male Emperor.
Later, Dark Green Fritillaries dashed across our path and vanished as swiftly. These restless, shining orange jewels leave one breathless at their glowing colour and exhilarating movement. It is a pity, though, that they rarely allow a close view.
Near the end of the track connecting Lullymore and Lullybeg, where the two buckthorn trees grow together, a faded Brimstone arrived, still laying her eggs. We netted her for a close view to find her wings perfectly in order, after an adult life-span of over ten months. She was released and resumed her egg laying almost immediately.
There was one mystery. A large, dark butterfly was observed, fluttering around the tops of birch trees. If seen in Europe, it might be expected to reveal a Camberwell Beauty or Purple Emperor. But it did not descend, and the mystery of its identity remains.
A special thanks to the large number who attended and showed great enthusiasm for nature’s wonders. It was a lovely experience for all.
On the morning of June 22nd 2018 this lovely male Dark Green Fritillary emerged from its chrysalis low down in the vegetation on Lullybeg’s Crabtree Reserve. The butterfly is named for the green suffusion on the underside of the hind-wing. This stunning butterfly is a very powerful flyer, even in areas exposed to strong winds. Unfortunately, it is extremely difficult to approach, especially in hot weather.
The status of the Dark Green Fritillary on the Red List of Irish Butterflies 2010 is vulnerable because of a population reduction that is projected or suspected to be met in the future (up to a maximum of 100 years) based on a decline in the area of occupancy, extent of occurrence and or habitat quality. The key threats are loss of coastal habitats to erosion and golf links and a reduction in quality of remaining habitats which are suffering from the encroachment of invasive species, because these areas are no longer grazed and are left undisturbed. The encroachment of scrub on limestone, heaths and bogs is a threat to it on these habitats, as is tree planting (usually of conifers) on cutaway and cutover bogs. Destruction of limestone pavement and high quality calcareous grassland are sinister threats to this dynamic and handsome butterfly.
The species was formerly common on the cutover bog in Lullybeg. Sadly, about ten years ago it became very scarce and almost disappeared from the Lullybeg area. Steps were taken to make the habitat suitable for this magnificent species. Common Dog-violet is the main larval host-plant. The plant was largely absent from the open grassland on the reserve and the violets that exist on the reserve had become shaded by developing scrub and woodland. Heavy shade means that the violets are unsuitable for the larva. To create conditions suitable for the species, violets were planted in clumps on the open grassland. Invasive scrub with violets growing underneath was cut back manually or removed with Bord na Móna’s assistance using heavy machinery. This brought the violets back into the light. The grasses returned which provides cover and basking areas for the larva. The well developed woodland areas with violets within them were left undisturbed as this habitat is used for breeding by the Silver-washed Fritillary butterfly. The Silver-washed Fritillary also uses Common Dog-violet as the larval host-plant but its larva requires some shade for it to develop. This approach highlights the need to manage a site sensitively; actions taken to benefit a species should not damage or remove habitat for another, unless an urgent priority exists in favour of a highly endangered species. Retention and maintenance of a range of habitats is best practice especially when a large site is available for nature conservation.
The next step was to reintroduce the butterfly. A small number of adult butterflies were obtained from a large population and these were released into the habitat in 2016. Breeding was suspected in June 2017 when a female was observed on a patch of violets.
This deep orange butterfly perched on fresh green vegetation is a glorious sight on a sunny June morning, and it is heartening to see its return. Hard toil is rewarded!