Month: August 2022

In late summer and early autumn, we still have a large number of species flying.  A good, ‘natural’ garden stocked with native herbs and trees can attract all of the species featured below. Here is a selection of these butterflies and moths. All but one of the moths shown are strictly nocturnal and spend the daylight hours concealed among the leaves of trees and shrubs.

All photos J. Harding

The National Biodiversity Data Centre (NBDC), based in Waterford, has been tracking the fortunes of Ireland’s butterfly populations since 2008. Using 2008 as the baseline for abundance, the recording scheme used by the NBDC the Irish Butterfly Monitoring Scheme (IBMS), involves 26-weekly transect walks carried out during the main flight period from April 1 to September 30. This scheme tracks abundance and flight periods. In addition, the Five-visit Monitoring Scheme also collects data on abundance.

The news emerging from the NBDC over the past two years is concerning. In 2020 and last year the multi-species index showed that once again there was a moderate decline in the number of butterflies flying when compared to the baseline year of 2008 (the start of the monitoring scheme). In terms of the individual species trends, no species shows a positive trend with only two species having ‘stable’ trends and all other species showing either ‘declining‘ or ‘uncertain’ trends when compared to the baseline year of 2008.

In Britain, a new Red List has been published this year, showing that half of Britain’s remaining butterfly species are listed as threatened or near threatened. The Irish Red List, published in 2010 and outdated classifies 33% of our species as threatened or near threatened. The List should have been re-evaluated in 2020 but will now be revised following the collation of data for the Irish Butterfly Atlas 2017-2021, probably in 2023.

When the Irish list is re-evaluated, it is likely that some additional species will be red-listed.

Nostalgia often leads us to think that the past was a better time, and butterfly memories charm reminiscence. We recall times of butterfly abundance in fields and gardens, but the absence or scarcity of data means verification of abundance trends is elusive. What can be gleaned from records taken before 2008 are some indications of distribution change.

It is quite clear why some butterflies are no longer found in certain places. Clearly, when land is built on, the composition of species that live on the land will change, with some doing well, such as the Holly Blue, which finds suburbia highly convivial, and others, like the Wall Brown, disappearing. The more disturbing and mysterious feature of butterfly loss is when a species has vanished, but the habitat remains, apparently unchanged. Subtler forces are at play when this occurs, and such circumstances can be difficult to discover and may be beyond our ability to address.

Some land use changes that cause distribution loss are avoidable and often irreversible. The widescale drainage of bogs, afforestation of bogs and peat extraction has certainly reduced the distribution of bog species, especially the Large Heath butterfly. Extensive changes in land management, particularly farmed land, have powerful impacts on butterflies, especially because 85% of our land is farmed.

A relatively new threat is the impacts arising from introduced invasive alien species, especially along hedges and stone walls in the countryside. The rampant weed, Montbretia, is a serious pest species, forming dense bands along hedgerows, eliminating all native herbs that butterflies, moths and other invertebrates require for their life cycles. This problem is increasingly acute, because of the increased relative biodiversity value of our native hedges and associated extended margins. Recently, Montbretia is appearing along the boreens of the Burren to sinister effect.

We appeal to everyone, especially if you live in a rural area, to remove this plant. It can be easily pulled up and the bulbs will yield easily. These must be destroyed. There are websites that advise on the eradication of this extremely damaging weed.

Another culprit is Fuchsia, a shrub that often accompanies Montbretia, and which is another invasive alien species that displaces native plants. While undeniably pretty, the plant has very little value as a breeding plant, unlike the native shrubs it crowds out. It is hard to get rid of once established and may need to be killed using an herbicide. Our advice is to avoid planting it and grow a native shrub instead.

If the avoidable threats from introducing non-native plants cannot be dealt with, our deeper problems are even less likely to be tackled. However, conservation is also about what not to do.

Do not grow non-native plants, unless you want them in your garden, but make sure they stay there. Do not buy peat for the garden or the fireplace. Leave peat where it belongs, in the bog. Do not buy electricity from wind or solar suppliers if the electricity they generate is derived from infrastructure built on bogs. Our bogs have taken all the abuse they can, and more. They must be re-wetted and allowed to begin recovery of their distinctive habitats and carbon capture capacity.

On top of the things that we need not do, there is a lengthy to-do list. Much of this relates to changes needed in the way our land is farmed, and this is a huge policy question internationally. The widescale use of chemicals is a very significant challenge along with the use of single or reduced-species swards to graze livestock.

A related, and global challenge to biodiversity, of which butterflies are one of the most charismatic and visible symbols, is climate change. Climate change is strongly associated with the over-exploitation issues already stated, as well as its link with industrialisation. Pollution, which is a driver of climate change also changes the soil conditions needed by butterfly foodplants, while increasing temperatures cause a complex range of challenges and outcomes which vary according to species and location.

Therefore, issues such as land use changes and climate change influence butterfly distributions, but the NBDC report quoted in the introduction deals with abundance trends (and flight times) in other words, how large our populations are compared with their 2008 baseline.

When only two out of our 35 butterfly species are recorded as having a stable population, we should not doubt that our butterflies and wildlife generally are under pressure, as a direct result of our behaviour.

The two stable species are the Peacock and Brimstone, although the evidence so far submitted to Butterfly Conservation Ireland this year suggests abundance declines for both in 2022.

The really worrying feature is the decline of very common, widely distributed species. Our best-distributed butterflies are four whites: Large, Small, Green-veined White and Orange-tip, the Small Tortoiseshell, and three browns: Speckled Wood, Meadow Brown and Ringlet.

Selecting one year only will not tell us much if anything about trends. Let us see how these did in 2008-2020 and 2012-2021.

 Large White:

Trend 2008 – 2021 – Strong decline (-76%)

Trend 2012 – 2021 – Moderate decline (-34%)

Small White:

Trend 2008 – 2021 – Strong decline (-77%)

Trend 2012 – 2021 – Moderate decline (-44%)

Green-veined White:

Trend 2008 – 2021 – Strong decline (-87%)

Trend 2012 – 2021 – Strong decline (-59%)

 Orange-tip:

Trend 2008 – 2021 – Strong decline (-68%)

Trend 2012 – 2021 – Moderate decline (-20%)

Small Tortoiseshell:

Trend 2008 – 2021 – Moderate decline (-49%)

Trend 2012 – 2021 – Uncertain (no significant change, changes likely to be >5% per year)

Speckled Wood:

Trend 2008 – 2021 – Strong decline (-78%)

Trend 2012 – 2021 – Moderate decline (-40%)

Meadow Brown:

Trend 2008 – 2021 – Strong decline (-86%)

Trend 2012 – 2021 – Moderate decline (-70%)

Ringlet:

Trend 2008 – 2021 – Strong decline (-88%)

Trend 2012 – 2021 – Strong decline (-62%)

 There is a group of butterflies that are not as widespread as these but are still widely distributed but more specialised in their requirements. Two examples are given here.

Small Copper:

Trend 2008 – 2021 – Moderate decline (-69%)

Trend 2012 – 2021 – Uncertain

Small Heath:

Trend 2008 – 2021 – Moderate decline (-76%)

Trend 2012 – 2021 – Uncertain

The IBMS report 2021 does not make any attempt to interpret the reasons for these declines but changes in how land is farmed must be the greatest influence on populations. Chemical usage is a major factor driving declines. Two doses of NPK fertiliser per year plus an application of herbicide rids grasslands of plant diversity and benefits a small number of vigorous grasses. Add to that the spread of non-native, invasive species on the last strips of farmland, the hedge and strip of parallel land at the field margins, especially adjoining public roads, and the last vestige of habitat is lost.

There is little doubt that habitat loss is the major factor driving the current declines of widespread butterflies, and that widespread, severe environmental degradation is the key issue. With a degraded environment, resisting and adapting to climate change is becoming impossible.

Moreover, add cobblelock and tarmacked driveways replacing gardens, public green spaces planted with useless and harmful non-natives and mismanaged, and our best wild places neglected.

We get what we deserve.

In F. Scott Fitzgerald’s novel, The Great Gatsby, an incident occurs when a drunken guest who attended Gatsby’s party crashes the car into a wall, causing it to lose a wheel.

“But how did it happen? Did you run into the wall?”

“Don’t ask me”, said Owl Eyes, washing his hands of the whole matter. “I know very little about driving-next to nothing. It happened, and that’s all I know.”

“Well, if you’re a bad driver you oughtn’t to be driving at night.”

“You don’t understand,” explained the criminal. “I wasn’t driving. There’s another man in the car.”

…a pale dangling individual stepped out of the wreck, pawing tentatively at the ground with a large uncertain dancing shoe.

“Wha’s matter?” he inquired calmly. “Did we run outa gas?”

“Look!”

Half a dozen fingers pointed at the amputated wheel-he stared at it for a moment, and then looked upward as though he suspected that it had dropped from the sky.

“It came off,” someone explained.

… “Wonder’ff tell me where there’s a gas station?”

At least a dozen men, some of them a little better than he was, explained to him that wheel and car were no longer joined by any physical bond.

“Back out,” he suggested after a moment. “Put her in reverse.”

“But the wheel’s off!”

He hesitated.

“No harm in trying,” he said.

(The Great Gatsby, Penguin edition, pp. 55-56)

This incident foreshadows a much more serious car accident later when the consequences of human excess, irresponsibility, and delusion destroy the most vulnerable in the story. The motor car operates as a symbol of wealth, status, individualism, and human achievement yet it plays a major role in the destruction of idealism and happiness. The novel implies the moral and ecological bankruptcy of man’s exploitation of nature when the serious accident occurs in a grotesque “valley of ashes,” an industrial wasteland presided over by a billboard showing pair of sightless eyes, mistaken by a grieving character for the eyes of God. Without seeing where we are heading, without heeding the relationship between our treatment of  Earth’s ecosystems and our reliance on them, we will lose more than our butterflies.

The butterfly is a symbol of all that is good and healthy in our world. Where they abound in their diversity of species, the ecosystems are healthy and functioning as they should be. As August stands on the doorstep of September, enjoy the butterfly spectacle now on show in nectar-rich gardens. Spectacular though it is it will be of short duration. Their brevity and vulnerability should touch us to respect and love our butterflies and the landscapes they represent even more.

Key Reference

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

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

When will we ever learn? Nature is in crisis. Changes in land and sea use, overexploitation of biological resources, climate change, pollution, and invasive alien species have eroded our once rich natural capital and pushed more species to the edge of extinction than at any other point in human history. In the last four decades alone, global wildlife populations have fallen by 60% because of human activities, and nature is now in steep decline in almost every corner of the planet.

We face the extinction of three-quarters of global biodiversity by 2100 if we continue to pump the same quantity of greenhouse gases into the atmosphere as we have during the past decade.

The effects of climate change on animal and plant populations can be simple and complex. A relatively simple example is that some animals that favour warm conditions are shifting their European distributions further north, and to sites with a northerly aspect and to more elevated altitudes as these areas, now warmer, become suitable. Some species that favour cool conditions are responding in the same way, to avoid the habitat and other changes created by increasing warmth and because the increased temperature is enabling these cool climate specialists to use areas that had previously been too cold.

There are limits to the success of these responses. In a scenario of continued temperature rises, some species, such as the montane and arctic butterflies (such as Lapland Fritillary Hypodryas iduna), will run out of higher ground and cooler terrain to retreat to. This species breeds in damp habitats such as bogs and marshes. Increased heat will change the character of these areas resulting in habitat change and likely extinction. One of the world’s rarest species, the Sinai Hairstreak Satyrium jebelia, breeds on buckthorn bushes growing at altitude on the Sinai Peninsula. High-mountain endemics with very restricted ranges are likely to have a high risk of extinction under the various scenarios of global warming.

Endemic to the high mountains of the St Katherine Protectorate in South Sinai, the total world population in 2012 was estimated to be 1,010 individuals. Aspects of hostplant and habitat quality were significant predictors of the presence of Sinai Hairstreaks on individual trees. No immediate threats are evident except global warming: if current climate-change predictions for Egypt are correct, the quality of habitat and plant diversity will decrease in the St Katherine Protectorate, with negative conservation results likely (Power et al. 2014).

Let us look at just a couple of our butterflies, the Small Tortoiseshell and Peacock butterflies.

The Small Tortoiseshell butterfly is faring better in Ireland than in Britain. Here the population is regarded as showing a moderate increase (Judge and Lysaght, 2020) while in the UK it has shown a significant major decrease in abundance of -73% from 1976-2014 (Fox et al. 2015). It should, however, be noted that the Irish abundance study covered a shorter time (2008-2020) than the UK study. The species has declined in abundance by over 70% in Europe (Van Swaay, pers. comm. April 2021).

However, we should not be complacent about the butterfly’s abundance in Ireland. The arrival of the parasitoid, Sturmia bella, a fly species, in England in the late 1990s (first confirmed in Peacock caterpillars in Hampshire in 1998) has had a significant impact on the Small Tortoiseshell (and to a lesser extent, on the Peacock butterfly) in England. S. bella occurs naturally in Europe and its appearance in England may be the result of accidental or deliberate introduction or the result of climate change. S. bella lays its eggs on nettle leaves which are ingested by Small Tortoiseshell and Peacock caterpillars. The egg hatches inside the caterpillar. The parasitoid kills its host after the caterpillar pupates. The grub descends from a thread to pupate on or in soil.

A study by Gripenberg et al. (2011) found that the fly was present in 26% of larval groups of the Small Tortoiseshell assessed and that survival was 25–48% lower in batches of Small Tortoiseshell larvae where S. bella was present, indicating that S. bella causes host mortality in addition to that caused by native parasitoids. In some batches, all the caterpillars were infected. S. bella was found as far north as Lincolnshire, and the Small Tortoiseshell has declined significantly south of Lincolnshire but not north of this county. The report concludes that S. bella may be playing a role in the recent decline of the butterfly but “further research is needed to establish its effects relative to other potential drivers of trends in the abundance of this butterfly.” (Gripenberg et al. 2011)

S. bella also attacks the Peacock, Comma, Painted Lady, Speckled Wood and other butterfly species, but none of these are in decline in England. The Peacock’s stable status might be partly because the Peacock favours different breeding sites, particularly nettles close to woods, where S. bella is less common and because the Peacock, which is single-brooded, produces its larvae mainly between April and June, when S. bella is not numerous. The Small Tortoiseshell produces two or even three broods, and the second brood of larvae, in July, coincides in time with the abundance of S. bella.

A further climate-related problem for the Small Tortoiseshell is that prolonged dry weather in mid-summer reduces foodplant quality which may cause longer development times for the larvae or which results in the butterfly cancelling reproduction in the year of its birth and undergoing a reproductive diapause until the following spring. This necessitates a prolonged hibernation with adults entering their dormant state in July instead of September/October. This strategy helps the butterfly avoid second brood production which is more at risk from the effects of malnutrition and S. bella than its first brood, produced in spring. But it would certainly be at increased risk from animals that have not yet over-wintered and that use Small Tortoiseshell hibernacula as roosts or breeding sites, such as Brown Long-eared Bats Plecotus auratus.

The Small Tortoiseshell and Peacock have several native parasitoids to contend with. Larvae of the Small Tortoiseshell and the Peacock are also attacked by several other parasitoid species, of which the most common ones are the ichneumonid wasp Phobocampe confusa Thomson, the braconid wasp Cotesia vanessae, and the tachinids (fly species) Phryxe spp., Pelatachina tibialis, and Compsilura concinnata. These are all endoparasitoids (the parasitoids develop inside the host), and in all cases the parasitoid larvae emerge from the fully developed caterpillars before host pupation.

Small Tortoiseshell pupae (and the pupae of several butterfly and moth species) are attacked by a wasp, Pteromalus puparum, discovered in Ireland in 2002 (but present before that date, with the earliest known museum specimen dated 1928) which lays its eggs into newly formed, still soft pupae. Although the pupa is aware it is being disturbed and wriggles vigorously, it has no defence. Instead of a butterfly emerging from the pupa, tiny wasps, which may number over 100, bite their way out and exit through tiny holes. This parasitoid wasp is widespread in Ireland and has been found as far apart as Warrenpoint, County Down (1928), Glengariff, County Cork (1943) and Drumachon, County Kildare (2015).

Aside from S. bella, the native parasitoids have been present in England and Ireland for a long period, and these did not cause a prolonged decline in the species. However, irresponsible behaviour such as deliberate introduction can bring in a new parasitoid that creates severe difficulty for our native species.

A warming climate also encourages colonisation events, bringing threats to our indigenous species. It should be underlined that S. bella is native to Europe, so the great decline in the Small Tortoiseshell in the continent has not been explained by reference to the fly, and the causes of decline are currently unknown. However, could the decline be attributed to a warming climate favouring the fly?

And does the warming climate mean that the fly can make greater use of other host species? One reason for the Peacock’s lower vulnerability to S.bella is its use of nettles at wood edges, where the Peacock has a warmer micro-climate. However, recently the Peacock has also been observed using nettles in more open situations, possibly because the warming climate now makes these suitable; I have encountered several Peacock larval clumps on nettles along a track running through an open field.

For the second year in succession, the Peacock has shown a great decline in abundance in many areas in Ireland. This has been noted as a widespread reduction, in areas as distant as the Burren, County Clare, Lullymore, Co. Kildare, and County Antrim. This is a sudden and dramatic abundance decline, following the Peacock showing a “strong increase” 2008-2020 (Judge and Lysaght, 2020). The Peacock is believed to have benefited from the warming climate. In the 1960s it was a rare migrant to northern Scandinavia. In the 1970s it began to acclimatise, beginning to survive hibernation over the winter. Today, it is one of the most abundant Nordic species in late summer (Haahtela et al. 2011).  Parasitoids might be responsible, however for the population reduction during the past two years. The coming years will tell us if this decline is a trend, but it is far too early to make any assessment.

One useful conservation response the gardener can make is to allow nettles to grow in different areas, in semi-shaded, unshaded, exposed and sheltered locations. Heterogeneity in the location of the nettles offers the best hope of satisfying the breeding requirements of the Peacock under the changing circumstances wrought by the changing climate.

We are incapable of reversing climate change as individuals, and whatever the causes driving the decline of the Small Tortoiseshell in England, one fact is at least clear. One should not bring plants (including from overseas nurseries), eggs, larvae or pupae from Europe into Ireland or Britain, or from Britain into Ireland. The immature stages of butterflies often contain parasites or even viruses which our butterfly populations do not need, especially with climate change and habitat change and loss added to the challenges faced by our beleaguered butterflies.

Key References

Fox, R., Brereton, T.M., Asher, J., August, T.A., Botham, M.S., Bourn, N.A.D., Cruickshanks, K.L., Bulman, C.R., Ellis, S., Harrower, C.A., Middlebrook, I., Noble, D.G., Powney, G.D., Randle, Z., Warren, M.S. & Roy, D.B. (2015). The State of the UK’s Butterflies 2015. Butterfly Conservation and the Centre for Ecology & Hydrology, Wareham, Dorset.

Gripenberg, S., Hamer, N., Brereton, T., Roy, D. B., Lewis, O.T. (2011). A novel parasitoid and a declining butterfly: cause or coincidence? Ecological Entomology, 36, 271–281.

Haahtela, T et al. (2011) Butterflies of Britain and Europe. A&C Black, London.

Judge, M and Lysaght, L. (2020) ‘2019, the year of the Painted Lady’, The Irish Butterfly Monitoring Scheme Newsletter, Issue 13.

O’ Connor, J. P. 2002, “Pteromalus puparum (L.) (Hym.: Pteromalidae), a chalcid new to Ireland” The entomologist’s record and journal of variation Vol. 114 pp. 111-112. Available at https://www.biodiversitylibrary.org/part/194950 (Accessed 22 August 2022)

Power, A., Zalat, S. & Gilbert, F. 2014, “Nowhere left to go: the Sinai Hairstreak Satyrium jebelia”, Journal of insect conservation, vol. 18, no. 6, pp. 1017-1025.

 

Cast your imagination back 125,000 years. The climate then was as warm, on a sustained basis, as it has been in the past decade. Where Trafalgar Square stands today, alligators, hippopotami, and lions roamed the savanna while elephants grazed the banks of the Thames. Today,  Sir Edwin Landseer’s bronze lions guarding Nelson’s column grandly survey the Square where the wildlife consists mundanely of feral pigeons.

Imaginative indulgence conjures dreams of restoration ecology, beloved by hankerers for the recovery of ecosystems deficient in parts of the puzzle. In Ireland, such projects are usually concerned with iconic apex predators, such as the Grey Wolf, Red Kite, White-tailed Sea Eagle, and Golden Eagle. The latter three have been introduced to Ireland while the Grey Wolf is busy recovering lost territory throughout western Europe, under its own steam, but benefiting from the ban on poisoning and hunting that brought the animal to the edge of oblivion in most of Europe in the late 1970s.

But clocks are not easily turned back, and as the Covid pandemic demonstrated, we are not in control. The greater powers, the wrath of whom we have provoked, are in the ascendant. We are reactors, employing a scattergun approach to problem-solving that Manchester United’s transfer negotiator John Murtough would recognise, but be embarrassed by.

Our vulnerability to greater power than our meagre selves was spelled out to the cabinet committee on the environment and climate change in early May 2022 by Professor Peter Thorne, a lead author on the Fifth Assessment Report of the Intergovernmental Panel on Climate Change and one of the world’s leading climate experts.

Professor Thorne told the Climate Committee, which consists of the Taoiseach (Prime Minister), Tánaiste (deputy Prime Minister), Ministers of Public Expenditure and Reform, Social Protection, Agriculture, Climate Action, Tourism and Housing, that to keep the temperature below 1.5 Celsius above the pre-industrial era temperature, we need net emissions to reach zero by 2050. This requires halving methane emissions and getting carbon emissions to net zero.

You probably knew that. But then the devastating news was delivered that stabilisation of all effects of climate change is impossible in the next few centuries. Sea levels will rise by five metres.

There is nothing we can do to change this.

If you live in Cork City, Limerick, Galway, or Belfast you are in peril, especially if you are in junior infants’ class, typically a five-year-old. Here is what the sea level rise means for Dublin.

By the time our five-year-olds reach old age, Dublin will no longer contain Sandymount, Blackrock, Monkstown, Sandycove, Dun Laoghaire, and Ringsend on the south side and Malahide, Clontarf, Portmarnock and Sutton on the north side of the River Liffey. The Hill of Howth will be an island and there will be no Bull Island. The Liffey, by then hundreds of metres in width, will enter the sea at Phoenix Park. Dublin Bay will stretch from Cabra on the north side to Donnybrook to the south. The flooding will reach Lombard Street, near Trinity College.

The past 10,000 years have seen a remarkably stable global climate, allowing humans to develop from nomadic hunter-gatherers to settle in great urban centres facilitated by the industrial and agricultural revolutions. This climate stability is rapidly unraveling, according to Professor Thorne.

It will be worse elsewhere, such as on the Indian sub-continent, but we will feel the shocks, directly, economically, and in human terms, with mass migration to this country. We are at the edge of human livability in some areas already, such as the Horn of Africa, and this year, in parts of India.

If we are stupid enough to go to three Celsius above pre-industrial temperatures by the time our Junior Infants reach advanced old age, and this is where we are heading with current emission levels, 75% of all the planet’s biodiversity will be lost. Imagine what such a world would look like.

Many of our familiar plants and animals have ceased to exist. The photographs in The Irish Butterfly Book will likely show several extinct species. I wonder if the Wall Brown, Hedge Brown, Small Heath and Large Heath will still exist. These species are already in serious decline, and climate change and issues driving climate change are among the causes. The extinction list is also likely to contain the species that need well-drained skeletal soils: Dingy Skipper, Small Blue, and Pearl-bordered Fritillary.

There are studies concerning the link between the warming climate and butterfly declines. There are indications that a combination of climate change and pollution is damaging the habitat of the Wall Brown. Kurze et al. (2018) suggest that it is very likely that nitrogen enrichment from fertilisers is killing some species larvae on farmland while Habel et al. (2015) suggest that increased plant growth rates arising from nitrogen deposition, increased rainfall and climate warming are cooling the micro-climate at larval sites, driving declines of species that depend on nutrient-poor habitats.

A study that looked specifically at the Wall Brown’s decline, Impact of nitrogen deposition on larval habitats: the case of the Wall Brown butterfly Lasiommata megera by Klop et al. (2014) found that nitrogen addition to potted foodplants on which larvae were fed had beneficial effects on larval development. However, the study found the influence of nitrogen deposition on larval micro-site cooling the most likely reason for the decline: “The raised levels of green plant biomass under excessive nitrogen availability leads to an increase of both shading and green: dead ratios in the vegetation, which should be expected to result in a cooling of microclimatic conditions.”

Like Habel et al. (2015), Klop et al. (2014) believe the decline of heat-loving species “could be explained by a combination of excess nitrogen and climatic warming, with both factors enhancing plant growth in early spring and reducing the availability of warm microclimates.” Elevated temperatures at the larval micro-site, typically arising from a combination of unshaded bare patches of ground containing sparse foodplant vegetation and warm, dry, dead plant litter are critical to the caterpillar in spring when air temperatures are cool. If these findings are correct, geographical scale pollution reduction measures must be implemented along with measures to tackle climate change. If not, we could be lamenting the extinction of one of our formerly common and widespread butterflies.

However, in such a devastating context that Professor Thorne outlined, the fate of our butterflies may seem of small consequence, a trivial footnote to a doomsday of mass extinction and global crisis for mankind, with continued human existence at stake.

Thorne stated that a brief and closing window exists to secure a livable future if concerted global action takes place.

But the past decade has had the highest greenhouse gas emissions in human history.

Professor Thorne stated that technological solutions exist to produce low emissions, but investment, which is available, and leadership, are needed.

How, then, did the cabinet committee react to Thorne’s presentation? A few polite questions later, the ministers began to discuss sectoral contributions to emission reduction targets. The Irish Government reacted by producing, according to the Environmental Protection Agency (EPA) report published three weeks (May 31, 2022) after the briefing, an emissions policy that adds up to 28% of greenhouse gas (carbon dioxide, methane, and nitrous oxide)  reductions by 2030, not the required 50%.

When RTE’s HOT MESS programme sought an interview with any of the ministers who attended the briefing, no minister was made available.

Before we blame the Government, let’s look at ourselves. Do you want to sell your second car, get rid of your beloved SUV, pay higher taxes, and pay more for food?

I doubt it. But politicians need to lead public opinion, not follow it. Opportunities for leadership exist. Jim Hacker, the fictional minister in the British comedy, ‘Yes, Minister’, when asked to defy public opinion for the good of Britain, responded, “I am their leader. I must follow them.”

No more of that.

Policies that are unpopular now, will become more popular, over time, as people realise how crucial they are. Let us act so we don’t run out of it.

Sources

Dublin Live (2022) Terrifying flood map shows what Dublin will look like by 2030 https://www.dublinlive.ie/news/dublin-news/terrifying-flood-map-shows-what-23608348 (Accessed 19 August 2022)

EPA (2021) EPA Greenhouse Gas emissions projections highlight the need for urgent implementation of climate plans and policies. Available at: https://www.epa.ie/news-releases/news-releases-2022/epa-greenhouse-gas-emissions-projections-highlight-the-need-for-urgent-implementation-of-climate-plans-and-policies-.php (Accessed 19 August 2022)

Habel, J., Segerer, A., Ulrich, W., Torchyk, O., Weisser, W., and Schmitt, T., (2015). Butterfly community shifts over two centuries. Conservation Biology, Volume 30, No. 4, 754–762, accessed 28 December 2020, https://conbio-onlinelibrary-wiley-com.jproxy.nuim.ie/doi/epdf/10.1111/ cobi.12656

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

Klop, E., Omon, B. & Wallis DeVries, M.F. (2015) Impact of nitrogen deposition on larval habitats: the case of the Wall Brown butterfly Lasiommata megera. Journal of Insect Conservation 19, 393–402. https://doi.org/10.1007/s10841-014-9748-z

Kurze, S., Heinken, T. & Fartmann, T. Nitrogen enrichment in host plants increases the mortality of common Lepidoptera species. Oecologia (2018) 188: 1227. https://doi.org/10.1007/s00442- 018-4266-4

Natural History Museum (2014) London’s Wild Times: Past and Present https://www.nhm.ac.uk/natureplus/blogs/whats new/tags/britain_one_million_years_of_the_human_story.html (Accessed 19 August 2022)

RTE (2022) Episode 12 Getting Hotter. Available at: https://www.rte.ie/radio/podcasts/22110709-ep-12-getting-hotter/ (Accessed 19 August 2022)

World Wildlife Fund (2021) The Return of the Wolf in Europe https://www.worldwildlife.org/stories/the-return-of-the-wolf-in-europe#:~:text=Wolves%2C%20along%20with%20other%20predators,effort%20to%20prevent%20livestock%20predation. (Accessed 19 August 2022)

 

 

 

 

 

 

Our Burren outing began at 10 am when we gathered at the unofficial car park at the crossroads in the Burren National Park. The sky was grey, streaked with pale, fearful blue but the air was still, with a hint of warmth. Perhaps we would be lucky.

Following introductions, we over-stepped a low Burren wall and entered the area north of the road, where limestone pavement, open grassland, and scrub are beautifully flower-rich, with the heavily sweet influence of Fragrant Orchid flavouring the breeze, imbuing the atmosphere with alluring exoticism. To be there at this time of the year is to step into a dream world. August may be seen as summer grown old, a little wrinkled from its long exertions, frayed and browning, the glowing bloom of earlier days thinning and paling, paradise lost. The grasses are tinged with oatmeal, the light lower, sharper, flowers bedraggled.

The jaded look is challenged by the arrival of freshly hatched butterflies, especially our latest butterfly to take flight, the Brown Hairstreak, our main priority for this day. The Brown Hairstreak is the last Irish butterfly to emerge each year. Speckled Wood-sized, it is a most elusive species, common nowhere in Britain or Europe. Ireland has most of its brown Hairstreak populations in the Burren, with scattered presences in west Tipperary, south Galway, and in Mayo near Lough Corrib. But it is not easy to find, especially where tall oak trees occur, for the more active males tend to occupy tree-tops, rarely descending. The Burren has fewer tall trees, and very few oaks so we do see males at eye level, feeding on nectar, rather than aphid secretions on oak leaves.

Females are especially richly coloured with warm orange-brown undersides, while males usually look paler. Males are more active, jinking around the canopy, especially in the mornings, seeking newly emerged females. Mated females and males spend the long afternoons feeding on bramble and tall hedge side Creeping Thistles.

The overcast weather was against us, because the hairstreaks typically perch quietly on tall scrub, typically on hazel in the Burren. Before we reached likely habitat, we noticed the large population of fresh-looking Meadow Browns, sharply different from the diminished populations in the east, now in rapid decline, their life’s work already done. Common Blue, Small Copper, Ringlet, Grayling, and the occasional Small Heath were encountered in the tall sward.

The scrub patch identified in previous years as a good source of Brown Hairstreak sightings was searched. Nothing at first but high up one was seen, restless around the canopy before settling, wings ajar, on hazel. We failed to coax it to land lower down, but at least we knew they remained faithful to their patch. “If it brightens up, and you’re still around, you should find more here.” I learned that this is what some of our group did in the afternoon when the sunny weather appeared. A female was also found later, and they are rather lovely, in their tame, quiet, approachable way.

Later we crossed the road, finding another traditional haunt and another, less camera-shy male, who did fly down to feed on Creeping Thistle. A male Vapourer Moth was seen and photographed close by, a nice addition to the Burren Green and True Lover’s Knot moths caught the night before and shown to our group.

We later returned to our cars, for refreshments, and positive feedback on our outing. A great thank you to all who joined our outing, some having made long journeys to share an experience with nature. May the sights we saw live on in our memories, and may the amazing Burren continue to hold its amazing depth and range of wilderness and biodiversity.

Some years ago, a gardener told me she was enjoying the butterflies in her garden. It was early in a sunny September, and a range of butterflies flapped their vibrant wings around the nectar-filled blooms in her compact, warm sun-trapping garden. Did she grow any plants to encourage the butterflies to breed?

No, came the emphatic answer. She hates caterpillars.

But you cannot have butterflies without caterpillars.

No, she still didn’t want them.

The clarion call to save biodiversity is a cry that meets with broad public support nationally and internationally. Yet for many people, conservation is something that happens somewhere else. It is not. It is everyone’s responsibility. Covering your garden with artificial grass, tarmac, concrete, and cobbles do little to save nature.

Mowing your garden every week is damaging to the prospects of most wildlife and yet it is an endemic practice in Ireland, the UK and much of Europe. Yet many of the same people, if asked, would claim to care about nature.

Just as you cannot have the butterfly without the caterpillar, there is no biodiversity without a loving and hospitable home for our wildlife.

For most people, including butterfly and moth lovers, the larvae are rarely seen. But in some cases, the larvae are extremely interesting and very beautiful. Here we show a selection of butterfly and moth caterpillars and tell you a little about them.

All photographs J.Harding except Alder moth F. Parnell.