Butterfly Conservation Ireland

This week will have unsettled weather with plenty of cloud and rain. These conditions do not allow our longest-lived butterfly, the Brimstone, to emerge from its over-wintering quarters to begin its breeding cycle. Late in March is typically when it emerges to seek mates, feed and begin to look for breeding plants.

The Brimstone has one generation a year. In Ireland and Britain, eggs are laid during spring and early summer on two small native trees, Purging Buckthorn and Alder Buckthorn. Purging Buckthorn is found mainly on rocky ground in the midlands and west of Ireland, but also on fen peat on cutaway bogs and in hedges on lime-rich soils. Alder Buckthorn occurs mainly on boggy soils, especially in alkaline peat on cutover bogs and fens, in and at the edge of bog woodland, on moist heaths and limestone pavement. Both plants occur together in some places, such as in and at the edge of turloughs in the west of Ireland, notable in the Burren.

These trees have a highly localised distribution in Ireland with Alder Buckthorn much the rarer of the two plants. The only region where these tree species are relatively abundant is the Burren, in County Clare and Galway, the only area in Ireland where the Brimstone is plentiful. Elsewhere, the Brimstone occurs in scattered locations mainly across the midlands. The butterfly does not occur in Northern Ireland, the northwest, or the southeast and is very rare in the east and southwest. The butterfly breeds only where its breeding plants occur but it does not occur in every place its larval foodplants are found.

After mating and laying eggs in spring and early summer, the adults die off, but quite slowly, with some surviving as late as early July. During July and August, the new generation is emerging as adult butterflies, but unlike most of our butterflies, they do not breed until the following spring after hibernation is complete.

So how does the Brimstone deal with several months when breeding is impossible, when the weather is unsuitable, and food is unavailable?

The article looks at how the Brimstone manages to survive adverse conditions and why it appears to be more numerous in spring after hibernation than it was during the previous summer.

The Brimstone, unlike most of our butterflies, is sexually immature when it hatches from the pupa. A reproductive diapause occurs in this butterfly. Diapause is the suspension of development or activity in any life stage of a butterfly. This strategy is used to survive months of unsuitable weather which often corresponds with the period during which its breeding plants are unsuitable. Diapause is a rest period undertaken by butterflies, moths and other insects with a seasonal life cycle.

Diapause aligns the butterfly’s complete life cycle to seasonal changes in the environment to ensure that further development occurs in the most suitable conditions. Diapause is controlled by the neuro-endocrine system (hormones released by the nervous system). Furthermore, it is genetically determined for each species and once initiated, it is not influenced by surrounding climate developments, even when these are favourable for development. Diapause usually occurs in response to environmental stimuli that precede unfavourable conditions, such as declining hours of daylight (Nash et al. 2012).

In the case of the Brimstone, diapause occurs in the winged butterfly and takes the form of delayed sexual maturity. This is likely an adaptation to the coldest months of the year and the condition of the foodplants from July to April. Between July and October, buckthorn leaves are tougher than they are in April-June and perhaps contain toxins making them unsuitable for the larvae. In March and well into April, leaves have yet to appear on the plants.

In males, sperm develops during summer and autumn but the duct through which sperm passes during mating is narrow and contains few sperm before hibernation, but the duct is swollen and filled with sperm after hibernation. Female Brimstones hatch without developed eggs (which are small, unyolked and without an outer membrane), and these are fully developed only after the females spend several warm days on the wing in spring after hibernation.

Given that males are sexually mature immediately after emerging from hibernation, males immediately seek mates. However, females do not begin emergence at the same time as males. The males spend several days on the wing before the first females appear.

This mismatch in emergence is not unusual in Ireland’s butterflies. In most if not all our butterflies, males emerge first. What is the advantage of this pattern of earlier male emergence?

The advantage is that the females are located quickly and mated, and they can concentrate on laying their eggs. In most of our butterflies, females hatch from their pupae with fully developed eggs so laying starts soon after mating.

But the female Brimstone is not ready to lay her eggs on emerging from her pupa or even after several months of life, including for a period in spring after hibernation.

Yet there must be an advantage for male Brimstones to emerge earlier from hibernation. What this might be, appears to be unknown. Here are some possibilities. Female Brimstones, it appears, mate once, while males certainly mate with as many receptive females as possible. It might be an advantage for males to emerge earlier to seek females, including females that have yet to emerge from hibernation. The earlier the male emerges, the more mating opportunities he has.

Furthermore, it is possible that the older he is, the more fertile he becomes. It has been shown that the male Monarch butterfly Danaus plexippus older males produce a higher ejaculate mass, which means females receive more nutrients from older males, increasing female reproductive productivity (Wicklund et al. 1996).

Are there advantages for female Brimstones of earlier male emergence? It is possible that male Brimstones may be sensitive to pheromones released by other males during mating. This might mean that recently mated females are less attractive and less likely to be courted by males, allowing these females to develop and lay their eggs without the inconvenience of male harassment and the dangers associated with prolonged, conspicuous male attention, which must draw attention from birds and other animals.

An advantage for later female emergence is that the foodplants have extra time to develop. In March, neither of its foodplants is in leaf so food is unavailable for the caterpillar. By the time females are ready to lay, the leaves are further on in their growth, although the leaves are often unavailable until well into April. In cool spring conditions, eggs take longer to hatch, and this delay should help the larvae to appear when the leaves are available. It is important that newly hatched larvae have young, tender leaves, so synchronizing emergence, egg development, mating and egg laying with the development of the foodplant is very important.

Before adult butterflies hibernate, they must feed on nectar (and, in some species, fruit, and tree sap) to build reserves to survive the colder months without food. However, the Brimstone butterfly shows some surprising results. Release and recapture experiments in Sweden show that wild Brimstones put on weight within one or two weeks of first being caught but that when caught later weight did not increase but was maintained at a steady rate. Despite males having to devote resources to developing their reproductive system over winter males have not been observed to feed more than females before hibernation. It might be expected that having to devote resources to reproduction over the winter would reduce male survival rates. However, both sexes have similar winter survival rates (Wicklund et al. 1996). As far as I know, this has not been explained.

The Brimstone shows other unusual characteristics. A study carried out in central Spain during the period 2006 to 2012 looked at uphill and downhill migrations of the Brimstone. These movements are influenced by the resource needs of the butterfly at different times of the year and by temperature during the summer, in this case, the need to avoid extreme heat downhill. One aspect that surprised the researchers was the abundance of over-wintering Brimstones was higher than it had been the previous summer because the numbers must decrease during hibernation (some die of starvation, and some are eaten).

It is ecologically impossible that the population of a single-brooded over-wintering butterfly is higher in spring than in the previous summer before it over-wintered. The researchers rule out the possibility of immigration boosting abundance (the Brimstone is not a migrant) and state that the reason is unknown but it may be linked with differences in behaviour in summer and the following spring. They state that “reduced summer activity could also make (it) difficult to quantify potential downhill movement in late summer” (Gutiérrez, D., & Wilson, R. J. 2014)

While the Brimstone will behave differently under the climatic conditions in a mountainous region in central Spain and in a lowland area in Ireland, it is possible that the researchers miss an important detail about the Brimstone’s behaviour during the summer.

I have often been struck, as have others, by the often excellent condition of Brimstones in March and early April. Some individuals look pristine, very few have faded and tattered individuals are very rare. How is it possible that a butterfly can be active from July to late September and still present in excellent condition the following spring?

Intriguingly, Brimstones do self-care rather well. During the first few days after they hatch from the pupa, the butterfly is quite sedentary. It sits quietly in bushes or trees and does not draw attention to itself. It does not bask with its wings open but sits with leaf-like venated undersides on show, blending with ambient vegetation. In hot or cold summer weather, it takes to cover in foliage, concealed to great effect. On summer days when it is active, it is rarely out of cover before 11 am or after 4 pm, roosting early, sometimes before that that, reducing exposure time.

Brimstones are very good at not getting caught by the onset of bad weather. They are rarely seen away from sheltering trees, bushes, ivy, or dense sedge clumps, and react quickly to changes in weather. Brimstones can forecast rain, even when it is sunny, and will take cover in advance of rainfall (Adrian Hoskins, pers. com.). They know the difference between a cloudy spell and a lengthy period of overcast conditions; a feeding Brimstone will rest on vegetation during a cloudy spell and go to roost during persistent dull weather (Harding, 2021).

The butterfly’s general behaviour is quite conservative. While it can fly at a strong pace, it usually flutters from bloom to bloom in summer, avoiding the need for lengthy or conspicuous flights. It does not fling itself into tangled vegetation at any time of the year like some species do when mate-seeking or egg-laying.

The Brimstone cleans itself, using its legs to remove dust and debris from its head and thorax, and unhooks its proboscis to remove sticky pollen.

Despite these behavioral traits, a delicate insect is expected to show wear and tear after months of active living. Their generally good condition in early spring is a key reason why I do not believe the Brimstone spends several months in an active state before entering hibernation. While records show that the new generation of the Brimstone is active from July to late September or even early October, my transect records which extend over more than 10 years suggest that individuals are active for a few weeks and that most enter hibernation during the summer. The timing of over-wintering is likely dependent on when it hatched from the pupa and the weather.

Brimstone eggs are laid over several weeks, from late March to mid-June. Therefore, adult butterflies emerge from the pupa over an extended period. If a Brimstone hatched at the beginning of July it is probably in hibernation before the end of the month. If it hatches early in August it is likely to over-winter before the month is over. Prolonged bad weather during summer will see pupae lasting longer and adults resting in cover until conditions favour hatching from the pupa and feeding on flowers. If correct, this would explain why Brimstones are often seen during September, especially following a wet August. Finally, it makes no sense for a butterfly to expose itself to danger for months, especially when it is not in breeding condition.

Thus, perhaps there is no time during most Irish summers when one sees most Brimstones that reside in an area. However, in spring when all Brimstones are in the adult state there is a mass emergence from hibernation which in spring sees them concentrated in their often-discrete breeding grounds rather than dispersed across larger areas of flower-rich habitats. In the early stages of good spring weather, most of those seen are males but soon the females appear; the sexes are very active in spring, intent on finding mates and breeding plants. This behaviour makes counting large numbers easier, but the butterfly is not more abundant in spring than it was the previous summer before over-wintering.

However, the large concentration of these large, bright, characterful butterflies on bright sunny spring days is exhilarating after the drudgery of our muddy, damp, drab winter. The daffodil yellow males’ dash along the wood, hedge, and scrub edges brings vitality and pure joy to the nature lover, while the pale females delicate fluttering around buckthorns evoke living blossoms, their glowing leaf-like wings translucently petal-like in the crystal spring sunshine. Little wonder people see their first Brimstone as announcing the beginning of spring; little wonder English naturalist Matthew Oates called this mass emergence phenomenon, “National Brimstone Lift-off Day, the first truly warm day of the year”(Oates, In Pursuit of Butterflies, p. 220). It must be warm and sunny to tempt the Brimstone out in spring so when you see it, you know the weather offers the promise of happiness.

While the Brimstone offers the fascination of investigation, discovery, and ongoing inquiry, it offers much else besides, a view of a flower-rich countryside in the finest weather. The Brimstone is our ultimate sunshine butterfly, especially when back-sunlit wings are enjoyed. The male turns suddenly from matt yellow to gold in such light, inspiring for anyone, particularly for a photographer seeking to preserve the memory of a perfect experience, when the moment literally turns golden.

Look out for this moment in the weeks ahead…

 

References

Gutiérrez, D., & Wilson, R. J. (2014) Climate conditions and resource availability drive return elevational migrations in a single-brooded insect. Oecologia, 175(3), 861–873. doi:10.1007/s00442-014-2952-4

Harding, J. (2021) The Irish Butterfly Book. Privately published, Maynooth.

Learnaboutbutterflies.com

Nash, D., Boyd, T. and Hardiman, D. (2012) Ireland’s Butterflies a review. Dublin Naturalists’ Field Club, Dublin.

Nelson, B., and Thompson, R. (2006) The Butterflies and Moths of Northern Ireland. National Museums Northern Ireland, Belfast.

Oates, M. (2015) In Pursuit of Butterflies. Bloomsbury, New York.

Wiklund, C., Lindfors, V., & Forsberg, J. (1996) Early Male Emergence and Reproductive Phenology of the Adult Overwintering Butterfly Gonepteryx rhamni in Sweden. Oikos, 75(2), 227. doi:10.2307/3546246

Under the Wildlife Acts, hedgerow cutting is banned during the period March 1st to August 31st inclusive.

This ban is legally enforced, and many prosecutions have been taken by excellent National Parks and Wildlife conservation officers charged with protecting our diminishing heritage. Burning, cutting, and grubbing vegetation during this period is also prohibited.

If you see anyone breaching the law, take photos of the incident and machinery and contact your local National Parks and Wildlife Service officer. You can also contact the Gardaí.

The following are the contact details for the National Parks and Wildlife Service.

The Eastern region:

https://www.npws.ie/contact-us/eastern-division

Northern region:

https://www.npws.ie/contact-us/northern-division

Western region:

https://www.npws.ie/contact-us/western-division

Southern region:

https://www.npws.ie/contact-us/southern-division

Hedges are especially important for butterflies and moths. 65% of Irish butterflies use hedges. Some use hedgerow trees as breeding plants, some use grasses and flowers growing on the warm margins for breeding. In addition, many adult butterflies use hedges as territory, mating stations, nectar sources, flight paths, dispersal routes, and hibernation sites. The Brimstone butterfly uses hedgerows for all these reasons, while the Brown Hairstreak uses hedges for breeding, meeting and mating, feeding, and as a flight path.

A study by Merckx et al. (2012) found the hedgerow trees and extended width margins locally increased the number of larger moth species (also known as macro-moths) but not the abundance. Interestingly, they found that species richness and abundance were not affected by intensive farming, measured by the amount of arable land in the landscape. Both mobile and less mobile larger moths did better when extended width margins and hedgerow trees were present.

The benefits of trees in the hedgerow were especially strong for tree-feeding species. Increasing the density of hedgerow trees was recommended to lessen the effects of agricultural intensification. The study underlined the value of hedgerow trees, claiming “a disproportionate effect on ecosystem functioning given the small area occupied by any individual tree”.

The study also found a link between increased macro moth populations and ecosystem functioning (in other words, the higher moth abundance and species richness improve biological community functioning).

Why is this? Moths are associated with higher pollinator success, which benefits crops and animals, and moths are an important prey base for a range of species.

A study by Coulthard et al. (2016) showed that hedges are very important flight paths for moths. 68% of moths in the study were observed at 1m from the hedge and of these 69% were moving parallel to the hedge. Hedges are believed to provide the sheltered corridors needed by flying insects in our generally open, farmed landscapes.

These studies highlight how crucial hedgerows and hedgerow trees are for butterflies, moths, and biodiversity generally. It is crucial that hedges are protected and correctly managed. A badly managed hedgerow can be disastrous for some of our rarer species. For example, many species that breed on hedges lay eggs on the newest growth. Unfortunately, it is this outer part of the hedge that is removed by cutting. The Brown Hairstreak butterfly is extremely vulnerable for this reason, and Berwearts and Merckx (2010) report studies that found that annual mechanical cutting of hedges removes 80-99% of Brown Hairstreak eggs. A rotational cutting system that involves cutting one-third of the hedgerows in an area each winter resulted in the butterfly’s longer-term survival.

Even more serious is the removal of hedgerows by farmers who want to increase field sizes. Outside protected areas, this can be done between August 31st and March 1st. Given the importance of hedgerows to butterflies, moths, and many other species, our landscape cannot afford such losses. Another damaging though the smaller-scale practice is the replacement of hedgerows comprising several native species with a single species hedge, often non-natives such as Common Beech, laurel, and leylandii, among others. In some parts of the west, non-native fuchsia hedging has become naturalized, disfiguring the landscape, displacing native species, and reducing biodiversity. These alien species are of much less value because they have not co-evolved with the other species naturally present here.

Our hedges are crucial to our landscapes, giving our countryside character, building a sense of place, and hosting much biodiversity. The poet Wordsworth described the hedgerows at Tintern Abbey as “Little lines of sportive wood run wild”. While some management is necessary, a more relaxed attitude would be a great boost to butterflies and much else!

References

Coulthard, E., McCollin, D. & Littlemore, J. 2016, “The use of hedgerows as flight paths by moths in intensive farmland landscapes”, Journal of insect conservation, vol. 20, no. 2, pp. 345-350.

Merckx, T., Marini, L., Feber, R.E., Macdonald, D.W., Kleijn, D. & Sveriges lantbruksuniversitet 2012, “Hedgerow trees and extended-width field margins enhance macro-moth diversity: implications for management”, The Journal of applied ecology, vol. 49, no. 6, pp. 1396-1404.

 

Butterfly Conservation Ireland Annual Report 2022 is now available here:

Butterfly Conservation Ireland Annual Report 2022

We hope you enjoy it.

The new book on Ireland’s butterflies, The Irish Butterfly Book, is available now.

Here is some of what Michael Viney said about The Irish Butterfly Book in The Irish Times:

Harding is quite used to overwintering small tortoiseshells and feels “a burst of delight to watch the butterfly surge into the sunshine in spring”. It’s part of the 25 years of his study that distinguishes a €35 quality paperback on sale from his home in Co Kildare.

The Irish Butterfly Book is definitive, engaging and heavy with glossy illustration. It covers the ecology, life cycles and food plants of Ireland’s 35 butterfly species, many of them around Harding in the midlands and more in some 40 habitats from Cork to Donegal. The sites are mapped and photographed, along with their likely species.

It’s a book full of knowledge, from Harding’s own painstaking observation and also new lepidopteral research. Most people are content just to have a name for a butterfly, but his essays on each species open up fresh worlds of interest, observation and mystery. Butterflies, their caterpillars and chrysalises don’t lead such casual lives after all.

The review is here: https://www.irishtimes.com/news/environment/another-life-what-to-do-if-you-disturb-a-butterfly-s-winter-slumber-1.4759961

Here is an extract from a review of the book by Seán Lysaght ( Seán is a poet and nature writer. His prose includes Eagle Country (2018) and Wild Nephin (2020). He has published several collections of poems and translations with Gallery Press, including The Mouth of a River (2007) and Carnival Masks (2014). His forthcoming collection, New Leaf,  was published by Gallery in May 2022).

Ireland’s butterflies have now got the study they deserve in this extraordinary, landmark publication by Jesmond Harding. Harding, who is indisputably the leading national authority on the subject, has been studying and recording this insect group for many years; remarkably, in an age of specialism and science, he works independently of any institution. His Irish Butterfly Book is the latest in a long and distinguished amateur line of Irish natural history, which includes William Thompson’s Natural History of Ireland (1849-56), Robert Lloyd Praeger’s Irish Topographical Botany (1901), RF Ruttledge’s Ireland’s Birds (1966), and Zoë Devlin’s Wildflowers of Ireland (2014).

Harding’s Irish Butterfly Book is a treasure of fascinating detail and no doubt will motivate many wonderful summer excursions in future years; it will be an indispensable reference book for experienced nature watchers, and it should charm and inspire less specialist lovers of Ireland’s natural heritage. In time, also, it is to be hoped that this superb book will have a future life as a redesigned pocket guide, perhaps in a second edition from a commercial publisher.

The mysterious behaviour of Ireland’s butterflies is explored in this book.

• Why do some female Speckled Woods flaunt themselves at males, while others behave so evasively?
• Can Brimstone butterflies forecast the weather?
• How do male Small Coppers react to persistent attacks from larger males?
• Why do some Small Tortoiseshells hibernate in July, months before they hibernate in other places nearby?
• How does the male Green-veined White react when he faces a highly competitive mating environment?
• Do social caterpillars cannibalize?
• Why do male Brown Hairstreaks ignore females after 11 am?
• Why do we never see Painted Ladies leave Ireland during autumn?
• Why do some male butterflies check caterpillar foodplants?
• Is the warming climate making life easier or harder for Ireland’s butterflies?

The culmination of over 25 years of study and based on thousands of records, THE IRISH BUTTERFLY BOOK  documents the full life cycle of every Irish butterfly from egg to adult butterfly and includes over 400 original colour photographs. There are one or more photos for each life stage of every species making this book the first of its kind.

Among the contents of this book are:

• Butterfly ecology
• Gardening advice
• Butterfly life cycles and behaviour
• A site guide detailing the best places in Ireland to see butterflies

THE IRISH BUTTERFLY BOOK also has its own YouTube channel (linked to within the book) where you can enjoy film footage of Ireland’s butterflies.

Beautifully presented and designed, with large font size and accessible text, this book is a great addition to the Irish wildlife bibliography.

Available directly from the author. ISBN 978-0-9560546-1-6. Softback. Full-colour printing, 328 pages. €35 inclusive of postage within the Republic of Ireland.

Contact: jesmondmharding@gmail.com.

Also available in selected bookshops. These are listed below.

For more, see https://www.facebook.com/profile.php?id=100078056964282

Book Sample Pages

 

 

Text and photographs © J. Harding

The book is also available from:

Antonia’s Bookstore, Navangate, Trim, Co. Meath

Bandon Books, Cloghmacsimon, Bandon, Co. Cork

Banner Books, The Square, Ennistymon

Bargain Books, High Street, Butter Slip, Kilkenny

Barker and Jones, 2 Poplar Square, Naas East, Naas, Co. Kildare

Books Upstairs, 17 D’Olier Street, Dublin 2

Bridge Street Books, Bridge Street, Wicklow Town

Charlie Byrne’s Bookshop, The Cornstore, Middle St, Galway City

Constantia, Unit 2, Supervalu Plaza, Navan Rd, Dunboyne, Co. Meath

Hodges Figgis, Dawson Street, Dublin

Just Books, 23 Pearse St, Mullingar, Co. Westmeath

Liber books, 35 O’Connell Street, Sligo

Maynooth Bookshop, Main Street, Maynooth

Midland Books, High Street, Tullamore, Co Offaly

The Castle Bookshop, Castle St, Gorteendrunagh, Castlebar, Co. Mayo

The Ennis Bookshop, 13 Abbey St, Lifford, Ennis, Co. Clare

Swift Books, 19a Burrow Road, Sutton, Co. Dublin

Vibes and Scribes Books, 21 Lavitt’s Quay, Cork

Woodbine Books, Lower Main Street, Kilcullen, Co. Kildare

The Irish Peatland Conservation Council: http://www.ipcc.ie/nature-shop/#!/The-Irish-Butterfly-Book/p/432271396/category=139703608

Birdwatch Ireland: https://birdwatchireland.ie/shop/

 

 

 

I hated school. That sounds bizarre after a career in education, but it is true. School was incarceration, an ordeal to be suffered, in my case, between the ages of 4 and 17.

I have very few positive memories of my years as a primary and second-level student. Endurance not fulfillment was the objective. Happiness was sought elsewhere.

Sunshine and butterflies and birds and wildflowers, the great ingredients of a countryside yet to be sullied by chemical fertilisers, were the antidote to school and much else.

School ends when summer begins and begins when summer ends. And the summer was the time of happiness. On the last day of school each year, always a half-day, I sprinted not home but to the fields where so much life was taking place. Fox cubs gamboled in June’s buttercup meadows, Chaffinches crafted their very beautiful nests in shrubs and Orange-tips, looking tropical against the emerald verdure, dashed along rides and hedges.

The former paradise close to my childhood home lies buried beneath the concrete of monotonous housing, roads, industrial estates, a massive shopping centre, and Tallaght Hospital. Staring into the wet dark of January from an upper floor room in the hospital two years ago, I ruminated at the grim transformation of the area, from happy farmland where Bord na gCapall had its leafy, wooded grassy home to the dark hulls of massed buildings, dimly outlined by the orange street lamps.

June is not really a school month; in primary school, June means school trips and for second level it’s a holiday month unless you’re caught for state exams. For me, June was Friday. July was Saturday; the school became a distant memory, and summer eternal. August was Sunday. As August aged, the ache in my stomach intensified. September was Monday.

The sun and glories of summer fade rapidly during September. Butterfly abundance diminishes before crashing at or even before the month’s decease.

Some years evoke the beguiling illusion that summer will be a permanent fixture. The summer of 1976 was a standout. I remember the hot sun, a life lived outdoors, and masses of ladybirds, their cheery red, black-dotted carapaces a fun sight. But the Mediterranean summer vanished, drowned by the retaliatory downpours of September, all the butterflies over for the year, overnight. No lead-in. No Ode to Autumn. No illusion that ice cream weather could extend into school time.

In fact, while my classmates and I stared in awe at the ferocity of the rain in September 1976, we were observing the end of summer for the rest of the decade.

Autumn held some pleasures. Before the dark, short days ushered in winter, there were Small Tortoiseshells, Peacocks, Red Admirals, and Speckled Woods to enjoy. In fact, in some years, like 2022, there were so many autumn Red Admirals and Speckled Woods I really imagined that winter was abolished and that the swallows wouldn’t return to Africa. A few days of cloud, heavy rain, and violent wind tore down that dream along with the leaves.

September saw me scouring the bleached grasslands and bedraggled hedges for lingering symbols of summer. I discovered a curiously late blooming bank of bramble, occupied with final fling Red Admirals,  year after year. Annoyingly, the exquisite scarlet and black creatures often perched out of reach, like a gleaming fruit that gleams all the more when unattainable. When my pocket money did extend to a butterfly net from the newsagents (there was a recurring conflict in my heart: HB Dracula ice-pop or net) the net was often impaled then ripped among the treacherous thorns or, more maddening, it detached from the bamboo and was marooned high on the bush. On occasion, a butterfly would heap the humiliation by entering the stranded net tented over a spray of the pink blooms to sup on the nectar. Why, I wanted to know, did everything always conspire against me?

Another winter-beating strategy was to bring summer indoors. One autumn I caught a newly hatched Red Admiral and attempted to overwinter it in a shoe box stowed below the stairs. I read, in one of my few butterfly books, that Red Admirals hibernate in central Europe. So why not here? This hibernation information is not correct, but it was a while before I realised that.

My strategy to prepare my pet for a lengthy overwintering phase involved sitting in the front room, TV on but lights out, a piece of cut fruit, usually peach, in my hand with my Red Admiral feeding on the fruit’s sweet juice. Seated siblings were under sit-still orders. This worked quite well. It taught me patience and stillness and afforded close observation over a lengthy period. I noticed how it sometimes lodged its feet in the exposed parts of the fruit, and gracefully dipped its antennae towards its often-stationary proboscis, ‘smelling’ its nourishment. Sometimes it dabbed its proboscis impatiently, possibly because the juice dried or hardened.

Newly hatched autumn Red Admirals spend several days feeding and will become quite docile. What happens when they are ‘full’ is not, as I believed, a long winter sleep but a long migration flight. After being tame for some days, my pet duly became restive, flying across the room to the TV screen. I turned the central heating off to simulate winter cold but parental interference kicked in when ice formed on the inside of the windows. Containment in the shoebox did not create slumber. Even in the pitch dark, the butterfly tossed its migration-ready self against the cardboard and never settled, eventually perishing, to my bemusement and grief.

During my formative years in the 1970s and 1980s, the talk was not about global warming but contrarily, a new ice age was expected. The rotten weather from 1977-1981 seemed to support this idea, and aside from 1983, 1984, and outstandingly, 1989, the 1980s had miserably wet ‘summers’, especially the three years following 1984.

The climate has certainly been feeling the increased heat since 2000, and we are seeing the response of nature to this warming trajectory. The colonisation and rapid expansion of the Comma butterfly in Ireland are believed to derive in part from the warming climate and associated causes, such as fossil fuel burning contribution to the nitrogen enrichment of soils, leading to healthier, more nutritious Stinging Nettles for the Comma’s larvae. The rising air temperatures allow the Comma’s solitary larva to warm up enough to digest protein-rich nettle. The solitary habit of the caterpillar is speculated as one of the factors telling against successful breeding here in the past because, unlike social caterpillars, the Comma caterpillar does not gather in a cozy gregarious heat ball the Peacock and Small Tortoiseshell caterpillars form.

The Comma is breeding here twice a year, with a second brood flying well into October, and in good numbers, enjoying the season’s delights, especially blackberries, ivy nectar, and overripe orchard windfalls.

These well-fed Commas then identify a secluded sylvan retreat to see out the winter.

But there is a butterfly that is really excelling itself at extending summer. For over twenty years, Frank Smyth, who observes butterflies along parts of the north Dublin coastline, has chronicled the radically altered circumstances of the Red Admiral in the Howth area.

In some milder coastal areas, nettles do not die back, and egg-laying late in the year has been observed many times since 2000 on Howth Head, County Dublin by Frank. He has also observed larvae throughout winter and spring and expects to see Red Admirals there every time he looks for them. In November 2021, I observed breeding behaviour inland in County Meath, 34 km from the coast. If recorders check nettles for eggs when they see the adult in late autumn, we may discover it has become a resident species over more of this country.

It is worth describing how the Red Admirals breeding in Howth responds to the low temperatures there from November to March. Frank Smyth’s observations show that the egg lasts a good deal longer than usual, up to ten weeks, and that the larval stage takes months to complete. This ability to prolong its development cycle enables the species to survive the coldest months and allows the adult to emerge when conditions are more favourable.

This prolonged breeding cycle over the winter has also been observed in Sussex, on England’s south coast, where Red Admiral eggs laid late in the year took 65-90 days to hatch (David Harris pers. com. per Frank Smyth). The Howth Red Admirals appeared as adults in late April and May (Frank Smyth 2018 pers. com.). In Southern England, eggs hatching in late November and early December produced adults by the third week in May of the following year (Eeles 2019). The offspring of those that migrated to breed in the warmer Mediterranean region emerge as adults in March and April (Thomas and Lewington 2014).

Remarkably, on March 7th, 2021, Frank Smyth observed egg-laying at Howth on small, unshaded south-facing nettles. Frank believes the female he saw laying her eggs to be a migrant, given he saw no other adults in the area. This is likely to be the earliest egg-laying recorded in Ireland to date by any species, and a fascinating example of what this beautiful butterfly is telling us about changes in our world.

This is a developing story. Frank has recorded good numbers of Red Admirals in Howth throughout autumn and on November 18th, 2022 he found 10 Red Admirals, some laying eggs, and a Painted Lady. It is late in the year for all (or perhaps for any) of these to be home-grown. They might be migrants from warmer parts of Europe, assisted on their journey by recent mild southerly winds which have been followed in recent days by gentle airflows. The still-lush nettles and flowering ivy give them what they need for breeding and feeding.

This is a new development. Red Admirals leave Ireland during autumn. That is well established. I have observed this myself, as have many others, especially birdwatchers along the south coast who see a large build-up of the butterfly in October, within sight of the sea, and then the butterflies suddenly vanish. Radar has also picked up southward migration in autumn, from England.

But inward Red Admiral migration in late autumn into Ireland was unknown until now. Frank’s observations of their development overwinter in recent years suggest that the Red Admirals laying now will be successful breeders. Intriguingly, there was a single, freshly minted Painted Lady with them. A fellow migrant, this species should not be here in late November, according to our knowledge of this butterfly.

The habits of these species are changing quickly, but these changes are not uniform. Most of our Red Admirals still leave in autumn, but a few now remain and, it now appears, some even migrate here to breed. The species is showing flexible responses to changes in the climate. It is this ability to respond to change that makes the Red Admiral a successful butterfly, and in this regard, it has some vital advantages. It is cold-hardy, which allows it to remain active in cool weather as long as it is sunny, and can fly in dull weather as long as it is mild. It is highly mobile, having the ability to abandon unsuitable areas and reach a habitat containing healthy foodplants hundreds of kilometers distant. It breeds on a robust plant that occurs in a range of habitats right across Europe, temperate Asia and north-west Africa. It is not capable of over-wintering as an adult butterfly, like the Peacock, but it can take shelter and rest for several days, possibly for weeks, without feeding. The immature stages are able to prolong their development times in cooler conditions, a feature crucial for successful development during an Irish winter and spring.

There are species that our warming climate will not suit and there is some indication that some of our butterflies are struggling to cope with changing temperatures and rainfall patterns. There are winners and losers in circumstances of change. But summer can still be found at Howth, even at the end of November, and despite our queasiness at climate-related changes, including changes that bring pleasure, the Red Admiral testifies to the resilience and adaptability of some of our butterflies.

 

Key References

Eeles, P. (2019) Life Cycles of British & Irish Butterflies. Pisces Publications, Berkshire.

Harding, J. (2016) The Comma (Polygonia c-album (L.)) (Lepidoptera: Nymphalidae) breeding in Ireland, with notes on larval development. Irish Naturalists’ Journal 35: 63-65.

Harding, J. (2021) The Irish Butterfly Book. Self-published, Maynooth.

Smyth, F. and Nash, D. W. (2008) Overwintering of the Red Admiral butterfly (Vanessa atalanta (L)) on the Howth Peninsula, County Dublin. Irish Naturalists’ Journal 29:81-86.

Thomas, J. and Lewington, R. (2014) The Butterflies of Britain and Ireland. (Revised edition) British Wildlife Publishing, Dorset.

 

 

 

 

 

 

 

 

Submission to the Consultation on the Draft Forest Strategy (2022-2030)

This submission is prepared by Jesmond Harding, a director and Conservation Officer of Butterfly Conservation Ireland. Jesmond is the author of two books on Ireland’s butterflies, Discovering Ireland’s Butterflies & their Habitats (2008) and The Irish Butterfly Book (2021). This submission addresses some of the content of Ireland’s Forest Strategy Implementation Plan (draft) the Stage 1 AA Screening and Stage 2 AA Natura Impact Report (NIR) produced for Department of Agriculture, Food and Marine (DAFM).

The Need for More Native Woodland Cover

Ireland needs more native woodland cover, especially with just about 2% of the land surface of the country used for native trees. The sensitive design and creation of native woodlands, using seed sourced from indigenous woodlands within Ireland, has the potential to create badly needed woodland habitats for Ireland’s native woodland bryophytes, plants, invertebrates, and vertebrates.

At a landscape scale, the most important consideration in terms of native woodland expansion is to reduce fragmentation and provide connectivity for species between woodlands and other semi-natural habitats within the surrounding area. Analyses show that 30% woodland cover within the landscape is a critical threshold – for most woodland species, this is the minimum proportion at which the landscape begins to function as a single, large wood. [1]

Given the size and distribution of native woodlands in Ireland, it will be difficult to achieve these targets regarding size and woodland cover. This, however, may be possible within some of our larger SACs and proposed NHAs and where native woodlands adjoin conifer plantations. A good example is found in the Woodford area of Co. Galway, where several native woodlands, including the Derrycrag (110 ha), Pollnaknockaun (39 ha) and Rosturra (18 ha) Nature Reserves, are embedded within an extensive forest area. In the context of limited resources, emphasis should be placed on expanding individual woodlands within existing forest matrices, rather than creating or expanding isolated woodlands in landscapes that are largely agricultural in nature. Suitable areas include, for example, parts of Waterford, east Wicklow, southwest Cork/southwest Kerry, central Clare / southeast Galway, and northeast Donegal, where there are already significant concentrations of native woodland. An exception should be made for isolated ancient woodlands, the boundaries of which should be expanded, where possible. The expansion of native woodlands can be achieved by native woodland afforestation on greenfield sites or by converting non-native conifer, broadleaved or mixed stands to native woodland. Where practicable, the latter is the preferred option.[2]

Ireland’s Forest Strategy Implementation Plan (draft) proposes new forest types, especially Emergent Woodland/Rewilding, which is especially welcome in the context of the foregoing. The document also proposes Forests for water, Amenity forests and Neighbourwoods. There is no need for non-native tree/shrub species in such woodlands. I strongly urge the use of native seed, collected in the vicinity of these proposed woodlands, to establish these woods.

Impact of Afforestation on the Marsh Fritillary butterfly

Ireland’s Forest Strategy Implementation Plan (draft) the Stage 1 AA Screening and Stage 2 AA Natura Impact Report (NIR) produced for the Department of Agriculture, Food and Marine (DAFM) indicates Annex II Species, Conservation Status and Forestry Related Pressures and Threats in Table 3. On page 32, the table quotes the 2019 Article 17 report as identifying no threat or pressure to the Marsh Fritillary butterfly relating to forestry.

This is not accurate reflection of the report  The Status of EU Protected Habitats and Species in Ireland (2019), or the threat posed to the species by afforestation. Page 52 of the report contains the following sentence:

Sites (occupied by the Marsh Fritillary) are often on marginal land in upland areas and the edges of wetlands and peatlands which are subject to pressures from agricultural conversion and afforestation.[3]

Analysis of Article 17 Reports submitted by  EU member states carried out by Butterfly Conservation Europe noted the following problems with protected grassland habitats. The prevalence of threats to grasslands described in the Article 17 reports show that abandonment of grassland management (no grazing or cutting of vegetation) is the chief threat, with 385 mentions in the reports. The second most prevalent is mowing or cutting of grasslands at 254 mentions, followed by overgrazing (240), natural succession resulting in change in the species present (148), use of chemicals to protect certain agricultural plants (111), afforestation (110), conversion from one type of farming use to another (87), conversion from other land uses to housing, settlement and recreational use (78), use of synthetic fertiliser on farmland (76), collection of wild plants and animals (72) and conversion to other forest types including monocultures (70)[4]. All these factors, except the collection of wild plants and animals, applies to Ireland’s grasslands. This information is derived from EU member state Article 17 reports, so the causes of decline across Ireland and the EU and the improvement steps needed are known. This needs to start in protected areas and in any new protected areas.

A key requirement of the Habitats Directive is that the effects of any plan or project, which is not directly connected with or necessary to the management of a European site, but which alone, or in combination with, other plans or projects, are likely to have a significant effect on a European site, should be assessed before any decision is made to allow that plan or project to proceed. The obligation to undertake a screening for AA, and if necessary, an AA, derives from Article 6(3) of the Habitats Directive (92/43/EEC) and both involve a number of steps and tests that need to be applied in sequential order.

The Marsh Fritillary occurs in several European sites, including where the butterfly is not listed as a qualifying feature of the site (the species is listed as a qualifying feature in 16 Special Areas of Conservation in The Republic of Ireland). The species (which has a highly localised distribution in most of the areas where it occurs in Ireland) exists in a metapopulation structure, meaning that it has a central population with outlying colonies that are lost during the periodic declines which are characteristic of this butterfly’s ecology, and which are then re-occupied during periods of expansion (one such expansion occurred in the long, hot summer of 2018). This means that the Marsh Fritillary’s large colonies must be protected and that corridors to outlying areas must also be preserved, which involves protecting the landscape. Without a network of managed habitats, the isolation of populations will result in the loss of this largely sedentary butterfly. Thus, a habitat beyond the boundaries of a European site occupied by the Marsh Fritillary or a breeding area that is not currently occupied by the butterfly requires protection from negative impacts to ensure the long-term survival of the species. [5]

At 4.6.4 Ireland’s Forest Strategy Implementation Plan (draft) refers to Molinia meadows as holding populations of the Marsh Fritillary, and correctly identifies the threat to this habitat type from afforestation. However, the Marsh Fritillary occurs in a wide range of grassland habitats. These include limestone grassland, grassy heaths, humid grassland on cutover bogs, the grassy, heathy margins of intact bogs, fens, eskers, wet meadows, marshes, woodland clearings, fixed sand dunes, and machair grassland. (One example of the damage done by plantation forestry to machair grassland and fixed dunes and dune slacks can be seen at  Murvagh Special Area of Conservation, Co. Donegal Site Code: 000133 where the plantation of conifers and the spreading of self-sown conifers has and is reducing the areas of habitat available to the Marsh Fritillary). The impacts on these habitats, also used by the Marsh Fritillary, must be considered, especially in view of the metapopulation structure and the need to protect a network of habitat areas up to 15 km (the furthest distance from a known population the adult has been found in Ireland) from European sites to protect the species.

Conclusion

The overarching statement for the Shared National Vision for the role of trees and forests is

‘The right trees in the right places for the right reasons with the right management supporting a clean, healthy and well protected environment and a sustainable economy and society’.

Butterfly Conservation Ireland agrees with this vision. The right places for the right trees are not high-nature-value lands badly needed by some of our threatened species and habitat types. A mosaic of open and wooded habitats can hold a great range of grassland, heath and wetland species, and return parts of the landscape to what may have been its natural state.

Jesmond Harding 10/11/2022

[1] Peterken, G. 2002. Reversing the habitat fragmentation of British Woodlands. World Wildlife Fund (WWF)-UK.

[2] Cross, J.R. & Collins, K.D. 2017. Management Guidelines for Ireland’s Native Woodlands. Jointly published by

the National Parks & Wildlife Service (Department of Arts, Heritage, Regional, Rural & Gaeltacht Affairs) and the Forest

Service. Forest Service, Department of Agriculture, Food & the Marine, Kildare Street, Dublin 2, Ireland.

[3] NPWS (2019). The Status of EU Protected Habitats and Species in Ireland.

Volume 1: Summary Overview. Unpublished NPWS report.

[4]   https://www.youtube.com/watch?v=D1PUk__cO_o&t=2180s

[5] Harding, J. (2021) The Irish Butterfly Book. Privately published, Maynooth.

One of the results of Ireland’s impoverished fauna is the lack of large wild grazers over most of our grasslands. This means that grazing by cattle, vital to maintaining semi-natural grasslands, has to be arranged as a direct conservation management tool.  This is true of our best semi-natural grasslands in the Burren Counties Clare and Galway, in Sheskinmore, County Donegal, Ballyteige Burrow, County Wexford, and on Butterfly Conservation Ireland’s reserve at Lullybeg.

Cattle grazing tackles the grasses that would otherwise form dense, tall mats that overwhelm the existing flora and inhibit the germination of new flora. Micro-climate variation is created by cattle grazing patterns, particularly by selective grazing and poaching.

Another issue to be tackled is scrub control and this is where human hands are needed. On a very grey Saturday when it threatened to rain but luckily remained dry, our volunteers focused on a long rectangular area very rich in flowers but with hundreds of birch saplings that pose a major challenge to maintaining species-richness.

The work we embarked on was not really taxing but was repetitive. Working methodically, hundreds of saplings, now leafless, were removed. The area, shown in a photo taken in dull light, is used primarily as a feeding area by the reserve’s butterflies.

Containing masses of Devil’s-bit Scabious, with occasional Common Knapweed, Common Spotted Orchid, Common Milkwort, Common Dog-violet, and hawk-bits, this grassland was especially favoured by the Comma and Red Admiral this autumn. It is also used by the Small Purple-barred, an uncommon, small but striking day-flying moth that is double-brooded in the area.

While we uprooted the birch and occasional willow, a great catch-up on our news and summer butterfly experiences coloured and animated our toil. It can be difficult for anyone who has not visited Lullybeg Reserve in its summer pomp to realise how this site, so bedraggled in its appearance in late autumn and winter, can boast such riches of beauty and biodiversity during the spring and summer.

When May comes, the work makes sense!

Thanks are due to everyone involved with this event, and all our friends and supporters.

 

Submission to the Citizens’ Assembly on Biodiversity Loss by Butterfly Conservation Ireland

Executive Summary

The most urgent matter is preventing any further damage to our protected habitats. This requires monitoring protected areas and applying the highest penalties on anyone who damages our designated habitats. A programme of eradication of non-native biological threats to our habitats should be rolled out nationally, especially to target invasive, non-native Fuchsia, Montbretia, Rhododendron, Cherry Laurel, Japanese Knotweed, and Himalayan Balsam.

Extending protected areas is needed to adequately protect species and habitats and to meet the need to protect 30% of our land under the EU Biodiversity Strategy 2030. A new National Park proposed for the Ballydermot area in northwest Kildare and east Offaly, the first in the midlands and the first to be located on raised bog habitat, will help to meet Ireland’s commitments to protect nature, tackle pollution threats and climate change.

Scientific research is needed to determine the causes of decline of our rarest butterflies and moths, and to calculate the Favourable Reference Value to judge how many sites should be protected. Management plans for such sites and for all protected lands and marine areas should be produced and implemented.

Semi-natural grasslands must be protected and farmed correctly to maintain and enhance their conservation status. Teagasc and the National Parks and Wildlife Service have crucial roles to play in supporting farming for nature.

Peatlands must be protected from any further drainage and depletion. Peat extraction and importation should be banned. Industrialisation and afforestation of peatlands must be prevented and reversed, and peatlands restored as fully as possible.

Clean/renewable energy generation should be promoted to reduce pollution, but associated infrastructure must be located in appropriate sites, and must not impact negatively on threatened habitats or species.

The area under native woodland must be greatly extended using native seed obtained from indigenous sources.

Hedges and extended field margins should be correctly managed and new hedges, comprising native species from indigenous sources, planted to reduce field sizes and create connectivity across the landscape. New legislation to prevent hedge removal may be needed.

Agricultural pollution must be greatly reduced to avoid further damage to our terrestrial and aquatic habitats.

Environmental education should be introduced as a discrete element across the primary and second level curricula, and training of ecologists reviewed to re-focus on the skills and knowledge needed to identify species and ecological conditions required for our most threatened species.

A restructured National Parks and Wildlife Service is required to discharge its remit to conserve, designate and advise on priority species and habitats, to implement nature conservation legislation and policies, to manage state-owned areas reserved for nature and promote awareness of natural heritage and biodiversity.

What path will our environment take? Semi-natural grassland, limestone pavement, scrub and woodland in the Burren, County Clare.

Introduction: The Context of this Submission

The Citizens’ Assembly on Biodiversity Loss has much loss to consider. The following presents Butterfly Conservation Ireland’s view on the biodiversity circumstances pertaining to Ireland and its implications for butterflies and moths and general biodiversity, and actions that can be taken to attempt ameliorate or remedy the environment degradation that besets this country.

According to the Natural History Museum in London, out of all EU countries (including the UK) only Malta is worse in terms of biodiversity loss than Ireland. This puts Ireland in the bottom 10% of countries globally in terms of biodiversity intactness. [1]We have no natural habitats left, and many of our semi-natural habitats continue to suffer neglect and direct removal. The greatest reason for biodiversity loss in Ireland is the change in land use, mostly for agriculture, especially since Ireland joined the EEC in 1973. Other drivers include invasive non-native species, afforestation, pollution, and climate change.

2. The Problems

Grasslands

Many of our butterfly and moth species depend on semi-natural grassland habitats. Grassland butterflies and butterflies associated with other habitats are excellent indicators of the health of the environment. Data on the abundance of most of Ireland’s butterfly species is easily recorded, given the high visibility of butterflies and their popularity with the public. The Irish Butterfly Monitoring Scheme run by the National Biodiversity Data Centre in Carriganore, Waterford, presents the data in annual reports, which are fed into the European Grassland Butterfly Indicator. The EU Grassland Butterfly Indicator is one of the indicators of the status of biodiversity in the European Union. It is an abundance indicator based on data recording the population trends of seventeen butterfly species in 16 EU countries.

The European Grassland Butterfly Indicator is based on the national Butterfly Monitoring Schemes (BMS) in 19 countries across Europe, most of them in the European Union. The Irish Butterfly Monitoring Scheme data is represented in these findings.

The EU Butterfly Indicator for Grassland species: 1990-2017 showed the following grassland species that occur in Ireland have declined across Europe, including Ireland: Wall Brown Lasiommata megera (strong decline), Small Heath Coenonympha pamphilus, Small Copper Lycaena phlaeas and Common Blue Polyommatus icarus (moderate decline). The trend status for the Marsh Fritillary, our only legally protected butterfly, was ‘uncertain.’[2] The data from Ireland supports the decline trend.

The results of the Irish Butterfly Monitoring Scheme 2021 show, as they did in 2020, that there was a moderate decline in the number of butterflies flying in 2021 when compared the baseline year of 2008 (the start of the monitoring scheme). In terms of the individual species trends, none of our butterfly species showed a positive trend with only two species having ‘stable’ trends. All other species showed either ‘declining‘ or ‘uncertain’ trends when compared to the baseline year of 2008[3].

While this decline exists across the EU, it is worse in Ireland. Furthermore, being an island, Ireland is isolated from European butterfly populations and a rescue effect, with individual butterflies migrating to areas that have again become suitable, is unlikely as most of our butterfly species are non-migratory.

Considerable significance should be interpreted in the decline of our most abundant species, the Meadow Brown Maniola jurtina which showed a trend 2012–2021 of moderate decline (-70%). The reason that this is especially significant is that this is a widespread species with low specificity in its grassland habitat requirements. It breeds on any semi-natural grassland even when fertiliser is applied. When an undemanding species is declining, widescale environment degradation is indicated[4].

The problems affecting grassland habitats in Ireland and across the EU are known from the Article 17 Reports provided by EU member states, including Ireland,  to the European Commission. Under Article 11 of the EU Directive on the Conservation of Habitats, Flora and Fauna (92/43/EEC), commonly known as “the Habitats Directive”, each member state is obliged to undertake surveillance of the conservation status of the natural habitats and species in the Annexes and under Article 17 to report to the European Commission every six years on their status and on the implementation of the measures taken under the Directive. In April 2019, Ireland submitted the third assessment of conservation status for 59 habitats and 60 species (including three overview assessments of species at a group level).

The most important grassland habitats for Ireland’s butterflies and the assessment of their conservation status in the 2019 report are: machair (Inadequate), Marram Dunes/White Dunes (Inadequate) Fixed Dunes/ Grey Dunes (Bad), Calcareous Grassland/Orchid-rich (Bad), Molinia Meadows (Bad), Lowland Hay Meadows (Bad), Alkaline Fens (Bad).[5] The report provides reasons for the assessments. The most cited reason for a negative rating is agricultural intensification (fertiliser use). Other causes mentioned are inappropriate grazing, land abandonment (where farming that had been beneficial has ceased), drainage, disturbance, and afforestation.

The reason for butterfly and moth declines and general biodiversity loss is linked, not with climate change but with the condition of habitats. Analysis of Article 17 Reports submitted by  EU member states carried out by Butterfly Conservation Europe noted the following problems with protected grassland habitats. The prevalence of threats to grasslands described in the Article 17 reports show that abandonment of grassland management (no grazing or cutting of vegetation) is the chief threat, with 385 mentions in the reports. The second most prevalent is mowing or cutting of grasslands at 254 mentions, followed by overgrazing (240), natural succession resulting in a change in the species present (148), use of chemicals to protect certain agricultural plants (111), afforestation (110), conversion from one type of farming use to another (87), conversion from other land uses to housing, settlement and recreational use (78), use of synthetic fertiliser on farmland (76), collection of wild plants and animals (72) and conversion to other forest types including monocultures (70)[6]. All these factors, except the collection of wild plants and animals, applies to Ireland’s grasslands. This information is derived from EU member state Article 17 reports, so the causes of decline across Ireland (and the EU) and the improvement steps needed are known. This needs to start in protected areas and in any new protected areas.

Peatlands

The butterfly species monitored for the grassland butterfly indicator are mainly widespread species. There are some habitat specialists dependent on habitats that are less common in our landscapes or that were common but have since been significantly altered or destroyed. One example is the Large Heath butterfly Coenonympha tullia which relies on bogs containing large areas of characteristic wet bog vegetation. Widescale peatland drainage and harvesting operations have impacted populations greatly but calculating distributional change by mapping at 10km resolution carried out by the National Biodiversity Data Centre fails to show the population decline that has occurred in Ireland over the last half-century or so. Given the specialised habitat requirements of this species, without habitat restoration projects which specifically recreate favourable breeding conditions for Large Heath, the conservation outlook for the species, (ranked ‘Vulnerable’ on the Irish Butterfly Red List[7] ) remains poor in Ireland.

However, most bogland is so severely degraded that recreating these conditions within any reasonable time frame is impossible, even when re-wetting is applied. The habitats produced on re-wetted bogs are typically reed swamp, poor fen and open water, unsuitable for the Large Heath and a range of butterfly and moth species, and for many other high bog specialist species.

The protected raised bog areas that remain continue to deteriorate. According to the 2019 Article 17 Report,

The main pressures on active raised bog are peat extraction, drainage, afforestation and burning. Climate change is also considered to pose a threat in the future. The Overall Status of the habitat is Bad and deteriorating, unchanged since the last assessment.

 If this continues, species that rely on this habitat type will disappear.

Scrub and Woodlands

Aside from grasslands, marsh, and bogs, the other main butterfly habitats are scrub and woodland. These often exist as mosaics with grasslands and wetlands. Ireland is deficient in native woodland. The remnants are generally hillside woods in Counties Kerry and Wicklow with small patches on old estates or inaccessible sites such as lake islands and eskers. Few native woods on fertile soils remain in Ireland. Plantations of non-native species, undertaken especially on what is considered marginal farmland and upland blanket bogs, not only removes important habitat but creates woodland that is unsuitable for Ireland’s biodiversity, including butterflies and most moths.

The total national area of forest is about 10% of the land surface, less than one-fifth of which consists of native woodland.[8] The result is that woodland butterflies are generally thinly distributed because their habitats are absent from many areas. The Purple Hairstreak butterfly Favonius quercus which requires native oak trees, is known from a single location in County Dublin (Phoenix Park) and County Kildare (Leixlip Castle). The species has a restricted distribution by the scarcity of habitat that would, without human interference, be common across our landscapes.

The pressures that affect the annexed habitat, Old Oak Woodland (Habitat Code 91AO) are non-native species such as Rhododendron ponticum, Cherry laurel Prunus laurocerasus and Common Beech Fagus sylvatica and overgrazing by deer. These impacts severely reduce tree regeneration, which is essential for the long-term viability of woodlands in conjunction with the continued fragmentation of remaining stands, lead to an Overall Status of Bad with a deteriorating trend[9]. The aim of the development of native woodland should be to have woodland throughout the landscape, connected by well managed hedgerows and scrub, and to have native woodland large enough to ensure that woodland animals and plants can move across the landscape, and woods large enough for people to get lost in.

 Hedgerows

Hedgerows usually contain native trees and are very important for butterflies, moths, and biodiversity generally, especially in our farmed landscapes. In Ireland, hedgerow trees and shrubs are mainly Common Hawthorn, Common Blackthorn, Common Hazel, Common Holly with gorse and Grey Willow commoner on wetter soils. Other plants that occur in hedges are Common Yew, Common Spindle, Common (Purging) Buckthorn, and occasionally Alder Buckthorn. Many hedgerows contain trees, especially Pedunculate Oak, Rowan, Common Ash, and Common Beech. 65% of our butterflies and many of our moth species are associated with hedges and extended field margins. Hedges that have large native trees that are allowed to grow are especially valuable[10].

Severe and widescale cutting of hedgerows is damaging to biodiversity. many species that breed on hedges lay eggs on the newest growth. Unfortunately, it is this outer part of the hedge that is removed by cutting. The Brown Hairstreak butterfly Thecla betulae is extremely vulnerable for this reason, and Berwearts and Merckx (2010) report studies that found that annual mechanical cutting of hedges removes 80-99% of Brown Hairstreak eggs. A rotational cutting system that involves cutting one-third of the hedgerows in an area each winter resulted in the butterfly’s longer-term survival.

Even more serious is the removal of hedgerows by farmers who want to increase field sizes. Outside protected areas, this can be done between August 31st and March 1st. Given the importance of hedgerows to butterflies, moths, and many other species, our landscape cannot afford such losses. Another damaging though smaller-scale practice is the replacement of hedgerows comprising several native species with a single species hedge, often non-natives such as Common Beech, laurel, leylandii, among others. In some parts of the west, non-native fuchsia hedging has become naturalised, along with Montbretia, disfiguring the landscape, displacing native plant species and reducing biodiversity, including in our most important habitats, such as in the Burren region. These alien species are of much less value because they have not co-evolved with the other species naturally present here.

Pollution Threats

The findings in a German study by Habel et al. (2015) entitled Butterfly community shifts over two centuries looked at the impact of atmospheric nitrogen loads and climate change over the period 1840-2013. The study found that high rates of atmospheric nitrogen deposition (from exhaust emissions, the burning of fossil fuels, wood, industrial incineration and the application of nitrate fertilisers) change nutrient-poor ecosystems, resulting in the replacement of plants in nutrient-poor habitats with plants that enjoy soils enriched with nitrogen. This results in butterflies that depend on nutrient-poor habitats, such as limestone grassland and heathland, disappearing, leaving a smaller number of butterfly and moth species that are adapted to plants containing high nitrogen levels.

The study further suggests that while habitat generalists (like the Peacock butterfly Aglais io) have benefited from increasing temperatures, habitat specialists have been negatively affected by increasing temperatures and rainfall. These effects may be explained by increased vegetation growth rates triggered by the combination of increased moisture, temperature, and atmospheric nitrogen. Greatly increased vegetation growth may also explain the apparently paradoxical situation that heat-loving species are declining in response to increased temperatures. However, higher vegetation growth rates, fostered by the combination of increasing plant nutrients, precipitation, and higher temperatures may produce a cooler and more humid microclimate close to the soil. The environment just above the soil is of particular importance in the development of the larvae of many butterfly species, such as the Small Heath and Wall Brown. Eeles (2019) [11]reports elevated levels of carbon dioxide which increases larval development times as another possible reason for the decline in the Small Heath.

The Small Heath is a widespread butterfly across Europe and attention is mostly focused on much less widespread species that are judged to require special protection. However, the decline in widespread grassland butterflies should set the alarm ringing, the proverbial canary in the mine. Unless the drivers of climate change are tackled, site protection may be insufficient save some of our more sensitive biodiversity over the longer term. However, the immediate priority is to deal with the damage being directly caused to our semi-natural habitats.

3. Recommendations

Solutions to be tailored to Species’ Habitats

It is impossible to protect butterflies, moths, or any animal or plant group without protecting its home.

We have the data and scientific knowledge to identify new areas that require protection under the EU Biodiversity Strategy 2030 which aims to protect 30% of the land area of the EU. Often the current protected areas are too small, and not well managed. Such distribution data and knowledge of the needs of specialised butterflies (butterflies with highly specific habitat needs) can be applied to expand protected areas or create new protected areas, such as former Bord na Móna peat extraction bogs, including the Ballydermot Bog Group area in northwest Kildare, a large wilderness area very rich in biodiversity, currently proposed as a new National Park by Ireland’s conservation NGOs, including Butterfly Conservation Ireland, Birdwatch Ireland and the Irish Peatland Conservation Council[12].

For protected habitat specialist butterflies the approach being used is to calculate the Favourable Reference Value for the population to judge how many sites must be placed under protection. To calculate Favourable Reference Value, required viable population size or species-specific or habitat type-specific features such as habitat suitability or required area for proper functioning are considered (Bonelli et al. 2021). Such an approach has been described which may protect some of the rarest species in Ireland possibly those listed below[13].

For rare species, such as the White Prominent Leucodonta bicoloria, Irish Annulet Gnophos dumetata, Sandhill Rustic Luperina nickerlii  and Pearl-bordered Fritillary Boloria euphrosyne, specific action plans are needed to cover issues such as monitoring population size, high-resolution distribution data and management of protected areas. Some of the management carried out under agri-environmental schemes do not give sufficient protection to scrub, which is often removed to increase the area of high nature value grassland, such as Calcareous /Orchid-rich Grassland. For some species, a mosaic of scrub and grassland is vital.

A further approach that can be applied in Ireland is the umbrella approach. Some habitats regarded as priority habitats under the EU Habitats’ Directive such as Calcareous /Orchid-rich Grassland (EU Habitat Code 6210) are butterfly-rich. By identifying areas of this habitat containing endangered butterflies protected under the EU Habitats’ Directive, such as the Marsh Fritillary, a case can be made for including such areas within the enlarged protected areas required under the EU Biodiversity Strategy 2030. Protecting habitats for the Marsh Fritillary protects many other species, making the Marsh Fritillary an umbrella species.

For species that appear to remain widespread, but which are suffering from changes such as changing farming practices, we need to work to persuade farmers to adopt measures to protect the habitats. Beautiful, charismatic species like the Small Copper should be used to promote protective practice, using funding from the CAP and other sources. Agricultural intensification is a great threat to this and many butterflies.

Some species, like the Dark Green Fritillary Speyeria aglaja and Marsh Fritillary need a different approach. The larva needs structured grassland vegetation with leaf litter.  Populations are being lost from protected sites because of natural succession. Action plans need to be written with a clear management prescription.

Management and monitoring (especially the use of citizen science), as well as protection from damaging activities are key to butterfly recovery. We suggest integrating the Butterfly Monitoring Scheme with specific guidelines for monitoring species listed in the Habitats’ Directive (in Ireland’s case, the Marsh Fritillary, currently under-monitored here). This approach requires working with citizen scientists and experts. While Butterfly Conservation Ireland, the Irish Peatland Conservation Council, and the National Biodiversity Data Centre monitor the Marsh Fritillary, we simply do not have enough transects (fixed-route walks carried out annually) to monitor this butterfly. A serious effort to apply the Favourable Reference Value to assess the Marsh Fritillary’s populations in landscapes important for its conservation, like the Burren, County Clare and Galway, Sheskinmore in County Donegal and Ballydermot in County Kildare, should be made through the National Parks and Wildlife Service to increase the protected areas that Ireland needs to pledge to the EU by the end of 2022 to help to address the biodiversity crisis afflicting this country.

If applied across our landscapes these measures will be of great value, but they may not be adequate to protect butterflies and biodiversity in the longer term. Most of our landscapes will not be strictly protected and even strictly protected areas will not benefit fully from these measures in the absence of much wider changes in how society operates because pollution is playing a role in the loss of some butterfly populations.

Grasslands

The correct management of our grasslands begins by not destroying any more semi-natural grassland. Because most of our land is farmed, the role of farmers is vital, and the role played by the farm advisory service, Teagasc (The Agricultural and Food Development Authority), is crucial. Teagasc has an advisory and instruction/education role. Unfortunately, it advises farmers to apply pesticides, herbicides, and fertilisers to their land, which destroys biodiversity, increases pollution, and drives climate change. It also promotes or has promoted single-species swards, devastating for most biodiversity. When Butterfly Conservation Ireland wrote to Teagasc to draw attention to research on the impact of nitrates on the mortality of some of our grassland butterflies[14], and offer our help to research nitrogen tolerance, our letter went unanswered. Teagasc must be much more responsive to ecological concerns, and not simply directed to ever-increasing production.

In some areas, farmland is being abandoned, which can result in improved biodiversity outcomes for a short time but eventually leads to habitat change and reduced biodiversity. Scrub and woodland follow with some woodland often comprising non-native self-sown conifers such as Lodgepole Pine.

Biodiversity-led agri-environmental programmes with well-researched results-based outcomes may benefit farming in areas of low agricultural productivity. Re-wetting drained farmland to restore habitats such as hydrophilous tall-herb swamp and marsh, with low intensive grazing using traditional cattle breeds, is highly sympathetic to biodiversity.

 Peatlands

The destruction of peatlands is the most egregious affront to the integrity of our landscapes. The race to drain, extract and burn peat is the gravest offence to our environment since World War II. The damage is done and is effectively irreversible on most peatlands where mechanised, large-scale exploitation occurred. All that can be done is to properly protect the remaining designated peatlands, applying the full penalties allowed to those who destroy legally protected habitats. We want the state to purchase bogs that are capable of regeneration instead of paying owners and holders of turbary rights to refrain from cutting peat.

We advocate a full ban on peat extraction and peat importation. We should not be importing peat at the expense of any other country’s biodiversity.

Re-wetting, calibrated according to the ecological circumstances of each site, should be extended to all bogs in state ownership, at a minimum. Industrial infrastructure, such as wind turbines, should be located at appropriate locations offshore, not on bogs.

Scrub and Woodland

The amount of land under native woodland and scrub must increase to restore biodiversity and restore the natural vegetation pattern. This may be done directly by planting native trees sourced from seed obtained from indigenous sources as close to the planting site as possible, and by allowing land to re-wild of its own accord. The interventions needed in a natural re-wilding to produce the best results will be the removal of any non-native trees, such as Sycamore, which offer little by way of food for native invertebrates.

Woodland should not be planted on highly biodiverse grassland unless a managed grassland/scrub/woodland mosaic is to be created. Farmers should be incentivised to allow a proportion of their land to develop scrub, rather than being penalised.

Ancient woodland sites that have been planted with non-native trees or which contain invasive non-native plants should have their native tree cover restored; a project to remove exotic conifers and Rhododendron and restore Sessile Oak woodland is currently in progress albeit on a limited scale, in Glengarriff, County Cork[15].

Any new tree planting along roads, especially motorway embankments, should avoid the use of non-native species, which are completely needless in such locations. The choice of species should be the same as those found in the locality. This advice also applies to planting in public parks, public green spaces and verges.

Hedgerows

The law in relation to the closed season for hedge cutting and removal must be enforced throughout Ireland and should not rely on the selective and sporadic dedication of individual Conservation Officers.

Hedgerow management advice provided by Teagasc must take account of the needs to biodiversity and farming. Rotational cutting, allowing individual hedgerow trees to grow, and encouragement for hedgerow retention (grants and other incentives) should be advised by Teagasc.

No non-native species should be planted in hedgerows. Extended field margins adjoining hedges should not be ploughed, re-seeded, or sprayed with agricultural chemicals.

 Pollution Threats

In addition to the comments made under the Grassland heading, more funding to increase grants to all homeowners to install solar panels is recommended to reduce pollution from the burning of fossil fuels. All public buildings should be fitted with solar panels. Power derived from wind energy must be increased with turbines located in areas where carbon sequestration, important habitats and species are not adversely affected.

The creation of more native woodland, re-wetting drained land will help to mitigate pollution.

Clear labelling should be introduced to inform consumers of the carbon and pollution cost of products such as mushrooms grown on peat substrates.

Farmers should be encouraged to deliver slurry and effluent to treatment plants instead of spreading the material on farmland. Treatment plants must be upgraded to deal with increased loads. Slurry should never be spread on semi-natural grassland.

Education

There is a great lack of biodiversity education in our primary and second-level schools. What coverage there is appears dependent on the enthusiasm of the individual teacher. In second-level schools, it is practically non-existent apart from the biology syllabus. Climate change is not the main driver of biodiversity collapse; habitat loss is the key problem.

Concern about climate change is often a celebrity-driven phenomenon, monopolising space better occupied by an awareness of the ravages caused by habitat destruction, especially of our wetlands, grasslands and woodlands. Remedying this damage will play a role in mitigating climate change impacts.

A broad appreciation for wildness, a love of nature, should be encouraged in our children. There is space in the second level curriculum, occupied by wellbeing, that can be dedicated to nature study. This can easily be integrated into the wellbeing programme: a day of tree-planting, a ramble in Glendalough, drain-blocking on a bog, pond-dipping, scrub control on a nature reserve, camping in a woodland, butterfly breeding and nature treasure hunts are all happy, healthy activities that can be carried out with or even without a detailed ecological context. Appreciation of such experiences can prompt curiosity, a desire to learn and to love nature.

The Transition Year programme particularly lends itself to environmental education. Modules should be developed by the National Council for Curriculum and Assessment (NCCA) for Transition Years to grasp the basics of ecology. This can feed into project work and may increase take-up of biology at senior cycle. The Environmental Studies module (optional for schools) (https://ncca.ie/media/2520/environmental_studies.pdf) could be developed further by developing the resources and connecting the material studied with complementary actions that effect or instigate real change, even if it is on a small-scale initially.

The worrying feature of the education of our professional ecologists is the dearth of knowledge frequently exhibited in ecological reports and in the field. The basics of habitat and species identification and knowledge of the ecological requirements even of species of conservation concern is disturbingly thin or entirely absent in some ecologists. There may be over-specialisation in the higher education training of ecologists; whatever the cause, it is disconcerting to see so few younger people with the knowledge required at this time of great need.

A Restructured National Parks and Wildlife Service

It should not take ten phone calls to reach the correct District Conservation Officer when attempting to report suspected damage to a Special Area of Conservation. The National Parks and Wildlife Service requires the correct complement of dedicated staff who are empowered to act to protect the environment without fear that their career progression will be negatively impacted by taking an ‘inconvenient’ case. Efficient, well-managed, well-supported competent staff are essential to any organisation. The courtroom should be the natural habitat for District Conservation Officers when environmental legislation is breached.

The capacity of the organisation to respond to planning applications that have the potential to negatively impact protected sites and species must be increased and maintained. The workload of conservation officers is frequently excessive with extensive geographical areas to cover. Some initiatives, such as the Burren Invertebrates Conference 2022, are excellent at showcasing the wonders of Ireland’s special places. To this end, the organisation’s website could be made much more attractive to view; while it contains important information, it lacks appeal for the general user. Furthermore, the premises used by the service are often hard to find, small and unattractive with little to inspire people. This should be remedied.

4 Conclusion

An integrated approach is required, involving in the first instance, farming, forestry, government, both local and national, planning bodies, especially An Bord Pleanála, professional ecologists and conservation and recording bodies, and conservation and recording volunteers. However, biodiversity loss is a challenge for society not just for those who can directly apply solutions on a more immediate level, because without a societal demand for change, the political will to effect change continues to be absent. We ask The Citizens’ Assembly to urge these recommendations on the Irish Government, to let those in power know that citizens want a healthy, butterfly-filled, nature-rich environment.

The Marsh Fritillary butterfly, Ireland’s only legally protected insect.

Jesmond Harding, Conservation Officer, Butterfly Conservation Ireland

 

About Butterfly Conservation Ireland

Butterfly Conservation Ireland (BCI) is a volunteer-run non-governmental conservation charity (Revenue Number 18161, Charities Regulator Number 20069131) founded in 2008 in response to the decline of our butterfly populations. BCI is dedicated to the conservation of butterfly habitats. BCI has a reserve at Lullybeg, County Kildare which we manage with Bord an Móna where conservation measures are applied to protect the excellent habitats so that the extraordinary butterfly and moth populations continue to thrive. We manage a reserve at Fahee North in the Burren in conjunction with the Burren Conservation Volunteers to protect Ireland’s rarest butterflies. BCI operates a recording scheme and shares the data with the National Biodiversity Data Centre. BCI holds events to showcase butterfly conservation and we provide regular educational content on our website and in our Annual Report. BCI provides advice concerning the conservation of butterfly habitats and advocates the protection and correct management of our landscapes.

The Ballydermot Bog Group area, County Kildare, is the ideal location for a new national park for Ireland.

Footnotes

[1] https://www.nhm.ac.uk/discover/news/2020/september/uk-has-led-the-world-in-destroying-the-natural-environment.html#:~:text=While%20countries%20such%20as%20Canada,UK%20only%20has%2050.3%25%20remaining

[2] https://butterfly-monitoring.net/sites/default/files/Publications/Technical%20report%20EU%20Grassland%20indicator%201990-2017%20June%202019%20v4%20(3).pdf

[3] Judge, M and Lysaght, L. (2022), The Irish Butterfly Monitoring Scheme Newsletter, Issue 14.

[4] Harding, J. (2021) The Irish Butterfly Book. Privately published, Maynooth.

[5] https://www.npws.ie/sites/default/files/publications/pdf/NPWS_2019_Vol1_Summary_Article17.pdf

[6] https://www.youtube.com/watch?v=D1PUk__cO_o&t=2180s

[7] Regan, E.C., Nelson, B., Aldwell, B., Bertrand, C., Bond, K., Harding, J., Nash, D., Nixon, D., & Wilson, C.J. (2010) Ireland Red List No. 4 – Butterflies. National Parks and Wildlife Service, Department of the Environment, Heritage and Local Government, Ireland, p.13

[8] https://www.npws.ie/sites/default/files/publications/pdf/Woodlands%20booklet.pdf

[9] NPWS (2019). The Status of EU Protected Habitats and Species in Ireland.

Volume 1: Summary Overview. Unpublished NPWS report, p.39

[10] Merckx, T., Marini, L., Feber, R.E., Macdonald, D.W., Kleijn, D. & Sveriges lantbruksuniversitet 2012, “Hedgerow trees and extended-width field margins enhance macro-moth diversity: implications for management”, The Journal of applied ecology, vol. 49, no. 6, pp. 1396-1404.

[11] Eeles, P. (2019) Life Cycles of British & Irish Butterflies. Pisces Publications, Berkshire, p138

[12] https://www.nationalpeatlandspark.com/

[13] Bonelli et al. (2021) https://doi.org/10.1016/j.ecolind.2021.108356

[14] Kurze, S., Heinken, T. & Fartmann, T. 2018, “Nitrogen enrichment in host plants increases the mortality of common Lepidoptera species”, Oecologia, vol. 188, no. 4, pp. 1227-1237.

[15] https://www.glengarriffnaturereserve.ie/

Reserve Management Event Postponed

The site management event planned for Saturday 5th November is postponed due to the weather forecast on the Met Eireann website.

We will attempt to hold the event on Saturday 12th November.

Please see the Events page for details.

We apologise for any inconvenience caused.

The site management event planned for Saturday 29th October is postponed due to the weather forecast on the Met Eireann website. (https://www.met.ie/forecasts/Leinster)

We will attempt to hold the event on Saturday 5th November.

Please see the Events page for details.

We apologise for any inconvenience caused.