Habitat destruction and butterflies it eliminates

Lockdown has been hard on people. Long periods without meeting friends and family, without working face to face with colleagues, without playing sports, and following our hobbies with other people are sorely missed. We need other people. That is how we are made.

One of our compensations is nature’s beauty, needed and appreciated more in our restricted circumstances. Bird song really cheers especially during spring when many species are in full voice. The Blackcap is particularly evocative of spring, having a varied, sweet, and melodious broadcast. He sings throughout the day in spring and well into summer. Gardens, woods, and hedges are occupied by this modest-looking bird, which appears to be thriving. Goldfinches, Linnets, Song Thrushes, Blackbirds, Chiff-chaffs are very vocal right now, often singing at the same time, making separating their songs tricky.

A rarer sound now is the call of the Curlew, a sweet but haunting call, made all the more evocative when heard drifting across a vast expanse of bog, surely our wildest and loneliest looking habitat. A dreamy, melancholic repeated note, there is just something mystical about the call, something that stirs in the soul.

So much rarer now, the species is numbered at around 130 pairs, a catastrophic crash mirroring the mass destruction of our bogs. The plummeting population of the Curlew and other birds are well recorded but many species are declining without our knowledge, silently vanishing, having no voice for us to notice their plight.

The mass decline and extinction of species from many areas is a stark underliner of our loss and mortality. By replacing natural habitats with agricultural grassland, we exchange the profound for the banal, biodiversity with impoverishment.  Our sense of place is altered, affecting us culturally and psychologically.  Who can sigh with satisfaction after replacing flower-filled limestone grassland with acrylic green sward nibbled to nothing by sheep? Who beams with pleasure when the character is ripped from the countryside? The ‘blanding’ of our landscapes carries on as I write; there is a hideous human drive, it seems, to ‘improve’ land.  The outcome is that we are all diminished and have so much less to leave to following generations.

In butterfly terms, many losses do not show up on distribution maps. The maps are often produced at the 10 km resolution, which does not pick up local extinctions. In some of these 10 km squares, a population of a particular species is confined to a single site but the map gives the impression that the species is well represented in that square.  A study by Thomas and Avery (1995) showed that maps at the 10 km resolution probably reflect real declines in only the rarest species, whereas declines of species of intermediate rarity may be underestimated by as much as 85%, and population losses of common species are unlikely to be detected at all.

One species that is now locally scarce but is not showing range contraction on butterfly atlases is the Small Heath. For species that are declining strongly, like the Wall Brown, the 10 km maps are showing range contractions. For butterflies like the Small Heath and Small Copper, To obtain a clearer reading of the status of butterflies like the Small Heath and Small Copper, maps with a more detailed level of resolution are needed.  If you can help with recording, please send in your records, according to the details here  https://butterflyconservation.ie/wp/records/

Why are declines happening?

Recently, a conservationist who carries out site surveys told me that he is seeing “habitat destruction everywhere” he looked. One does not need to look hard to see this depressing situation. Here are just some examples of habitat destruction and some butterfly losses arising.

Limestone grassland and pavement, even in areas protected by law, are being altered unnecessarily to facilitate farming. J. Harding
Limestone grassland south of Corofin, County Clare that is not legally protected, being destroyed. J. Harding
The Wood White ranked near threatened, relies on wooded habitat on carboniferous limestone that is being destroyed, especially in areas outside the Burren, such as around Lough Corrib, County Galway. J. Harding
The Pearl-bordered Fritillary is also reliant on habitats on karst limestone. Any removal of these habitats results in this threatened butterfly being lost permanently from that area. J. Harding
The Pearl-bordered Fritillary is named for the seven pearls bordering the underside of the hindwing. J. Harding
A raised bog in Kildare being destroyed for fuel. 2004 was the last year that Curlew was recorded on this bog. J. Harding
Green Hairstreak is a gorgeous, characterful and diminutive bog butterfly. It especially breeds on Cross-leaved Heath, a plant found on wet bogs. J. Harding
The Large Heath is tied to wet bogs. In his 2014 book, The Butterflies of Britain and Ireland, Jeremy Thomas, Professor of Ecology at the University of Oxford, warned that the Large Heath is experiencing “numerous local extinctions” in Ireland, which he describes as “a very great cause for concern”. Photo J. Harding

These are just a few examples of habitat damage. But there are many more, including around our own homes. Spraying chemicals to control “weeds” create damage, and this anti-social behaviour, while not as conspicuous as industrial-scale pollution and habitat loss, damages ecosystems too and says so much about our attitude to nature. Conservation starts at home. Let us all play our part.

 

Spring is here

Spring has really made its presence felt over the last week, with abundant sunshine bringing nature to life. Birdsong seems constant, with Blackcap, Chiff-chaff, Willow Warbler, Song Thrush pouring their music from scrub and hedges everywhere. The Barn Swallow arrived in early April and the Cuckoo has been heard in Donegal.

The Brimstone is on the wing in its open woods and scrub habitats that contain its breeding plants, Purging Buckthorn and Alder Buckthorn.  Orange-tips, emerging later than in recent years, are now flashing their gleaming, high-vis orange tips in bright sunshine while the less showy females already looking for egg-sites. Green-veined Whites are emerging too-a species to watch, given a recent decline. Large Whites and Small Whites are now hatching from their pupae and exiting the gardens where they pupated last autumn. Speckled Woods are out too-less conspicuous than the whites, but can be seen fluttering around grassy scrub and hedge edges edged with wild grasses.

Holly Blue, a much smaller butterfly than any mentioned so far, is highly prominent because their shining lilac-blue gleams in the sun. This active butterfly loves suburban and urban gardens with holly and ivy, the breeding plants for the first and subsequent generations respectively.

Comma, Peacock and Small Tortoiseshell butterflies are found in and around their Stinging Nettles, the food plant for their caterpillars. Males are quite territorial-while the sexes look identical, males will fly after any object thrown in the air, while the females ignore it.

Spring butterflies are at the mercy of the weather. Spring can collapse into winter very suddenly, and when this happens for a prolonged time, spring can be over for these early season fliers.  In short, enjoy the Orange-tips, Brimstones and the rest of spring’s insects, two of which are featured below, while they are here!

Brimstone laying an egg on Alder Buckthorn in an area cleared last winter. J.Harding
Freshly laid Brimstone egg. J. Harding.
Holly Blue, male, basking on ivy. J. Harding
Common Dog-violet in full bloom. This plant is the food plant for the caterpillar of the Silver-washed Fritillary, Dark Green Fritillary, and Pearl-bordered Fritillary. J. Harding
Green-veined White male butterfly taking moisture from damp peat., This butterfly may be taking water and minerals to replace those lost in mating. J. Harding
This Four-spotted Chaser has just emerged. This dragonfly is abundant in suitable habitats in May and June. J. Harding
The Green Tiger Beetle likes soft peat and sandy soils. A carnivorous beetle with serrated jaws, this species can cover 24 inches/60 cm in one second. It hunts by using its speed on the ground but it also flies, but for short distances. J.Harding

Opportunity Knocks

Brutus: There is a tide in the affairs of men.
Which, taken at the flood, leads on to fortune;
Omitted, all the voyage of their life
Is bound in shallows and in miseries.
On such a full sea are we now afloat,
And we must take the current when it serves,
Or lose our ventures.

Julius Caesar, Act 4, Scene 3, 218-224.

An era has ended for Ireland’s state-owned bogs and a new phase is beginning. Bord na Móna’s announcement in late 2020 that all peat cutting has ended on its estate coupled with the Government’s Peatlands Climate Action Scheme (PCAS) announced by the Minister of the Environment, Climate Action and Communications Eamon Ryan on 24 November 2020 marks a new beginning. This Scheme will see the Minister support, via the Climate Action Fund, Bord na Móna in developing a package of measures,  for enhanced decommissioning, rehabilitation and restoration of cutaway peatlands, referred to as the Peatlands Climate Action Scheme.  The additional costs of the scheme to rehabilitate peatlands are being supported by the Government through the Climate Action Fund, administered by the Department of Environment, Climate and Communications (DECC), while the National Parks and Wildlife Service (NPWS) will act as the Scheme regulator. (Details of the scheme can be found here https://www.gov.ie/en/publication/136a7-bord-na-mona-bog-rehabilitation-scheme/)

Before we get too excited, we need to consider the condition, among other important factors, of the peatlands being rehabilitated. Most of the peatland areas selected (and there are many bogs that have not been added to the scheme) are so severely degraded that it is not possible to restore them to anything resembling their once pristine condition. In short, the restoration of “active raised bog” as described by the European Union Habitats’ Directive Annex I   within the foreseeable future is not possible. In fact, the primary objective of the Government scheme is not habitat restoration but to turn carbon-emitting peatlands into carbon sinks to address climate change. This is a worthy objective, especially as the re-wetting is planned to set the peatlands on a trajectory towards the establishment of a mosaic of compatible habitats including wetland, fen, reed swamp, wet woodland, heath, embryonic sphagnum-rich peat-forming communities, scrub and birch woodland communities.

Refinements in the re-wetting measures will be applied where important grassland habitats have developed on parts of the peatlands selected for enhanced decommissioning, rehabilitation and restoration. This is key to protecting important butterfly habitats. Some bogs contain superb grasslands, including orchid-rich grassland one might expect to see in a very different habitat, such as in karst landscape and eskers. Some of the high-quality grasslands are so studded with summer orchids the fragrance is stunning, almost cloying in its concentration. Over this fragrant colour dance bejewelled butterflies like Common Blue, Dark Green Fritillary and Small Copper.

Modern farming has destroyed the vast majority of flower-rich grasslands making the biodiverse grasslands on peat soils the last bastion for many butterflies. Some species that are now unknown from farmland have found refuge in cutaway bogs (peatlands from which most of the peat has been removed).  There is, for example, no known viable population of the Dark Green Fritillary butterfly in County Kildare outside the Ballydermot Bog group area.

This area of bogland currently holds among the best butterfly and moth habitats and populations in Ireland. The area holds 25 butterfly species, some of these endangered, and hundreds of moth species, including endangered species. At around 7,000 hectares, in one large contiguous block, it is the right size for species to move around in the landscape, allowing species to find the best habitats for their needs and avoid genetic bottlenecks which damage a species’ vitality. Butterfly Conservation Ireland’s monitoring of the Marsh Fritillary in the area shows that the species is moving around in the landscape taking advantage of optimum habitat as it develops. We have noted that there is a high level of variability in the wing markings of the Marsh Fritillary butterflies in the region, a clear indication of genetic diversity. In short, the population of this endangered butterfly is healthy here and this must continue.

Once in a Lifetime Opportunity

Peat-cutting has ceased in the state-owned Ballydermot Bog group area. The machinery has fallen silent, and the sounds are now exclusively nature’s voices. Ravens and Whooper Swans in winter, Cuckoos and Willow Warblers and Great-spotted Woodpeckers in spring,  grasslands sizzling with grasshoppers and humming with the drone of bees shouldering their way through flowers in summer, followed by Goldfinches, Linnets and Lesser Redpolls delivering their liquid notes throughout autumn as they pick their way through the rich seed harvest.

Flowers bloom from April to October hosting various butterflies, bees, moths and much more according to the season. Vast native birch woods, shrubbery rich in birds, sky-reflecting lakes, ponds, dry and damp calcareous grassland, wet grassland, heath, fens, bogs abound. There is so much for the nature-lover and rambler to enjoy. The varied landscape gives a restless and artistic eye the drama of change to soothe and inspire. The area offers you the freedom to lose yourself.

And look where the area is, on the doorstep of the biggest population of people in Ireland, a wilderness offering exploration, freedom, health and happiness. I once brought a group of underprivileged urban teenagers to these bogs on a fairly dull spring day. After clambering out of the minibus they looked around, bemused. “Where are the shops?” “Where are the paths and street lights?”

I feared a long, long day. But no. They loved every minute of it. “Are we allowed to go here?”  There are no walls, boundaries or prohibitions to inhibit freedom. Of course, they jumped in every pond, drain and puddle available, amazed at frog spawn and “water lizards” (newts!) Notorious for their boisterous behaviour,  their exuberance was appropriate here, perhaps for the first time.

Why am I telling you this? Because there is so much more to nature and what it has to offer than hitting climate action and Water Framework Directive targets, very important though these things are.  Horse riding, walking, running, cycling, picnicking, scientific study for young and all other age groups are available along with tremendous physical and mental wellbeing benefits. And, perhaps above all, the vastness of the space offers great freedom. And all compatible with habitat restoration and nature conservation.

It is time to show vision, to take the opportunity now available. The west of Ireland has five national parks. There is no national park in Ireland’s midlands.  Without this landscape-scale protection, the long-term viability of many species in the region is in peril.  Butterfly Conservation Ireland, together will all the non-governmental environmental organisations, is calling on the Minister of the Environment, Climate Action and Communications Eamon Ryan, Bord na Móna, Kildare County Council and the National Parks and Wildlife Service to establish a new national park in the Ballydermot Bog group area, for nature, for people, forever.

Flower-rich habitat at the Ballydermot Bog group, County Kildare. Photo J.Harding
Lullybeg lake, on part of the Ballydermot Bog group, County Kildare. Photo J.Harding
Marsh Fritillary male, at Lullybeg, County Kildare. Photo J.Harding
Brimstone, male, Lullybeg, County Kildare. Photo J. Harding
Fragrant Orchid, common on orchid-rich grassland on the cutaway bogs in the Ballydermot Bog group region. Photo J. Harding
Small Copper, female. This declining butterfly needs the unfertilised, wild grasslands on our bogs for its survival. Photo J. Harding

 

 

Spring signs

In the butterfly world, signs of spring are often well concealed and most of the signs that are detectable are subtle and elusive. The glowing colours of the adult butterfly will only be seen later in the season in the case of most of our species so we must look hard for the signs that are available. Below are some of these signs. Let us imagine how these lead to greater glories as warmth returns.

Marsh Fritillary larvae bask together on their communal platform, warming each other to digest their food. Photo J.Harding
A close up of an individual Marsh Fritillary caterpillar feeding on the upper epidermis of a Devil’s-bit Scabious leaf. Photo J.Harding
This Marsh Fritillary caterpillar has just moulted and is now in its fifth instar. There are six instars in this species. When the sixth instar caterpillar has reached its full size it is ready to pupate. The pupa lasts around 2-3 weeks and the butterfly is usually seen from late May to late June. Photo J. Harding
Angle Shades larva. This caterpillar can be found in all months of the year. Photo J.Harding
Ruby Tiger caterpillars bask in spring. The moth is seen from May. Some specimens are a deep red, very striking when newly emerged. Photo J. Harding
The Hebrew Character is an early spring moth, flying from February. While not strikingly coloured, it reminds the dedicated moth watcher that brighter days imminent. Photo J.Harding
A Small Heath caterpillar, a rare sighting nowadays. This butterfly typically flies from May to August. Photo J.Harding
A male Common Quaker, an early spring flyer. This one was attracted to an outdoor light. This cryptically coloured moth is strictly nocturnal and is rarely seen, despite being quite common. Photo J. Harding
A reminder that nature is poised to take flight-this Large White chrysalis was formed on a window last autumn. The butterfly will emerge later this spring. Photo J.Harding

How Ireland’s Butterflies regulate their body temperatures

Ireland’s butterfly species operate in a relatively cool climate which presents challenges to these ectotherms, cold-blooded animals whose regulation of body temperature depends on external sources, such as a cool, shaded woodland or direct sunlight or a heated surface such as a mat of dead vegetation, branch or rock.  The metabolic activity and physical movement of butterflies are highly influenced by the thermal environment. This article looks at strategies butterflies use to deal with their thermal environment.

The adult butterfly needs to fly to escape enemies, to find food, mates and breeding sites. Efficient flight is only possible when the thoracic musculature, which houses the wing muscles, reaches temperatures in the range of 35-40 Celsius. Biological functions, such as mating, egg development and egg-laying, require certain temperatures (these vary according to the species). Air temperatures in Ireland rarely reach the levels needed so how do our butterflies reach the temperatures required for efficient flight and for the metabolic activities needed to sustain life?

During our butterfly flight periods, all our butterflies deal with thermal challenges.  These can be unsuitably hot or unsuitably cool conditions. A way to raise body temperature to enable the butterfly to take flight is wing muscle vibration. This is used by a butterfly during cool weather or when it has roosted in a cool location when it is unable to use external heat sources to warm its flight muscles. Wing muscle vibration, which looks like the butterfly is shivering, allows a butterfly to create enough heat to fly to or from cover but will not allow for sustained flight. The butterfly (or moth) vibrates its wings vigorously until it has created heat by friction that enables it to fly, usually weakly and briefly, to reach a suitable location. In cool, breezy weather this strategy may not work, leaving the immobile butterfly vulnerable to predation and severe weather. Occasionally, early on spring and autumn mornings, stranded butterflies can be found resting in the open on a flower from the day before, covered in dew.

Butterflies are efficient heat seekers, frequenting warm sheltered areas receiving direct sunlight even when these sites contain fewer resources than more open sites. It will be noted that open flower-rich grassland will often have fewer butterflies than expected, while sheltered rides in woodland with fewer nectar resources can hold an abundance of butterflies and other insects. Managers of nature reserves containing open, exposed grassland should be careful to allow some scrub, a resource that enables grassland butterflies to find shelter when the weather is cool, cloudy and windy. When the sun shines, butterflies will move into more open areas. As our climate warms, scrub habitats may become vital for butterflies to escape escalating heat during the hottest times of the day or season.

Butterflies also adopt thermoregulation strategies (regulation of body temperature) that vary according to species, habitat and temperature. The wings are used to regulate temperature, both to raise and reduce the temperature.  Most of our butterflies will bask with wings held wide open when they need to increase body temperature. This is known as dorsal basking. When the thorax is coolest, the wings are held fully extended and the extreme edges of the wings are pressed against the surface, often bare soil or rock. This is known as the ‘appression’ posture, proposed in one study as potentially different from dorsal basking. This is often seen used by the Small Tortoiseshell, Peacock, Comma, Red Admiral and Painted Lady-the first three species use this technique frequently on cool, sunny days in early spring. This technique is believed to be the most efficient for increasing thoracic temperature, by trapping warm air radiating from the surface,  trapping warm air radiating from the underside of the wings and minimising the flow of cooling air around and under the thorax.

Basking with wings held off the surface in a horizontal posture is used to warm the butterfly when it is cool but slightly warmer than a butterfly applying appression.  The butterfly is absorbing heat onto the wings, but experiments with dead butterflies show that only 30% of the wing area closest to the body is used to transfer heat to the thorax.  A heating thorax causes the basking butterfly to angle its wings, forming a shallower ‘V’ as the thoracic temperature rises until the butterfly folds its wings, a posture to allow cooler air to circulate around the thorax so the insect can cool down. If it becomes too warm for this thermoregulation strategy to be efficient, the butterfly seeks shade.

Lateral basking is another thermoregulatory mechanism used by some of our butterflies. This involves basking with folded wings where the butterfly perches on a surface and angles its wing surfaces by leaning sideways onto the sun to receive the maximum solar incidence when the insect is too cool. When the butterfly is warming, it starts to correct its posture until perched upright. When the butterfly is too warm it stands head-on to the sun, raising its body off the surface by standing tall. This strategy is used particularly and rather strikingly by the Graying, and less notably by the Large Heath, Small Heath, Green and Purple Hairstreaks and the Brimstone. The Brimstone uses this especially in spring, typically by basking on dry, dead grass clumps. Using this mechanism, it can raise its body temperature to the high 30s Celsius when air temperatures are barely above 13 Celsius.

The other form of thermoregulation used is called reflectance basking. This is used by some of the whites, especially the Large White, Small White, Green-veined White and Orange-tip, although these species will occasionally use dorsal basking when they need to recover a steep loss of body heat. The butterfly perches on a surface, usually a leaf, with wings half-open. It orients its position to receive sunlight onto its wing surfaces. The white wings reflect solar radiation onto the body to increase body temperature. A dusting of dark scales on the wings near the thorax may also play a role in heating the thoracic muscles. When it is too warm, the butterfly shields body tissues from the sun by folding its wings.

A thermoregulation mechanism used by the Brown Hairstreak to avoid over-heating on its sunny, sheltered hedge habitat is orienting its closed wings towards the sun, where its shiny undersides reflect rather than absorb the light. While this appears to be lateral basking, which is used to increase body temperature, this rare butterfly mainly uses dorsal basking to warm itself. Appearances can deceive!

Let us look at how adult butterflies respond to prolonged unsuitable thermal conditions. Migration involves butterflies leaving an area that is becoming unsuitable and moving to a location where their needs are met. It enables butterflies to escape the onset of prolonged unsuitable conditions typically caused by changing temperatures. An example of this strategy is the migratory habits of the Painted Lady, which extends its range progressively from early spring onwards through summer, from North Africa, throughout Europe. This continues until the onset of cold weather when return southwards migration of the species is undertaken by the children, grandchildren and great-grandchildren of the individuals that dispersed northwards earlier in the year.

Another response by adult butterflies to prolonged unsuitable thermal conditions (in Ireland these prolonged conditions consist of low temperatures) is hibernation. This is used by the Brimstone, Small Tortoiseshell, Comma and Peacock butterflies and by several moths, such as the Red-green Carpet, The Herald and Tissue. These species remain dormant until suitable temperatures return.

The next time you are outside looking at butterflies, look at the posture it is adopting. There is nothing casual, accidental or whimsical about the way butterflies perch, they are always doing what they do for a reason. There is a lesson for us in that, but you can decide what that is!

This Peacock butterfly is using appression to heat its body. ©J.Harding.
A male Common Blue using dorsal basking. Photo J.Harding.
This dorsal basking Small Copper is angling its wings as it warms. She is feeding on a buttercup in the County Clare Burren during warm weather. Photo J.Harding.
A Dark Green Fritillary with its wings closed. This photograph was taken during very hot weather in early July 2018. On the day in question, Dark Green Fritillaries were observed entering the hazel scrub to keep cool. © J.Harding.
This female Green-veined White is using reflectance to increase her body temperature. Photo J.Harding.
This male Brimstone is using lateral basking on a warm bramble leaf to warm himself during sunny weather in early April. Photo J. Harding.
This female Brown Hairstreak has closed her wings to reflect light to reduce her body temperature.  After this photograph was taken, the butterfly adjusted its position to increase light reflectance. Photo J.Harding.

 

Heat Up or Chill Out?

Our temperatures are increasing. All the indications show that all our seasons are warmer, spring is arriving earlier, the growing season is lengthening. How good is this for our butterflies? Here we consider just some of the results observed and ponder potential results that may arise from the ongoing climate warming.

Weather conditions play a major role in the abundance levels of our butterfly populations, while climate change plays a deeper role, influencing abundance and distribution of species. Let us start by looking at our three regular migrants. Three migrant butterfly species are considered to recolonise Ireland each year from southern Europe or North Africa: the Clouded Yellow, Red Admiral and Painted Lady. However, nowadays the Red Admiral is commonly present here during winter, blurring the distinction between resident and visiting species. There are also indications that Clouded Yellow larvae and pupae may be overwintering in warm, sheltered spots. This has been recorded in County Wexford.

We may receive new species that are expanding in response to the warming climate. In August 2013, there was a substantial influx of the Long-tailed Blue, with around 30 individual butterflies recorded, predominantly from south and east coast counties of England. In several cases, eggs or larvae were discovered at the same locations and, subsequently, an autumn ‘home-grown’ generation of Long-tailed Blues emerged across southern England, generating sightings of at least 80 individual butterflies spread across eight counties. Although the occurrence of Long-tailed Blue in the UK in 2013 was unprecedented in abundance and distribution, the species is not able to survive our winters and so permanent colonisation is impossible at present. Amazingly, another almost identical influx of Long-tailed Blue occurred in the summer of 2015, again with substantial local breeding and the emergence of a new generation. Milder winters may allow this very successful butterfly to become established in Ireland.

Another candidate for colonisation is the Swallowtail. The Swallowtail a large and spectacular butterfly that, occurs widely in continental Europe and on many off-shore islands. Sightings of this species have increased in southern England. Two were recorded here in recent years, including one last summer. As a highly mobile butterfly, it can reach our island and may become established here if temperatures continue to increase. The species over-winters as a pupa, which may be able to survive our winters as they warm.

We may also receive the Southern Small White as a new species. Until recently, and as its name suggests, this butterfly was confined to southern and especially south-eastern Europe, but it is now spreading rapidly in a north-westerly direction, at the rate of over 100 km per year. It was first found north of the Alps in France and in Germany in 2008 and has since gradually extended its range and was first sighted in the southern Netherlands in 2015. In 2019 it was reliably recorded near Calais in France. So there is only the matter of the 22 miles of English Channel to cross before it arrives on the UK’s shores.

Of course, it may already be in the UK, just not noticed amongst its cousins.  This expanding species is likely to be Ireland’s next new butterfly.  It breeds on Candy Tuft Iberis sempervirens, commonly grown in gardens, Rock Candy Tuft Iberis saxatilis and Bladderpod Alyssoides ultriculatum, which are also garden plants. It looks very similar to the resident Small White but can be separated from it by looking at the upperside of the forewings. The black wing-tips extend as far down the leading edge or costa as it does along the outer edge or termen. In the Small White, the black wing-tip extends further down the leading edge or costa. The forewing spots are more square rather than rounded and a thin black line extends from the forewing spot (from the forewing spot closest to the wing-tip in the female which has two forewing spots) to the black wing-tip where this extends down the outer edge (termen).  If you think that you have seen this butterfly, send us a photograph!

A butterfly success that is associated with increasing warmth is the Comma, unknown as a breeding resident until it was confirmed breeding here in 2014. It is now well established in the south-east and expanding northwards and westwards. It appears to be a matter of time before it is distributed throughout Ireland. Its larva is a solitary feeder, meaning it needs warmer conditions than larvae that feed in groups that help their fellows to absorb heat, like the caterpillars of the Small Tortoiseshell and Peacock butterflies.
The Peacock butterfly, a resident for as long as records can tell us, has increased in abundance in northern parts of Ireland, where it was much scarcer before the 1990s.

Another success being associated with climate ‘amelioration’ is the Holly Blue butterfly. Until the late 1990s, this was mainly restricted to old woodland in milder coastal areas and was very rare outside these areas. Not only is it found throughout much more of Ireland, but it is also producing more generations than it did. E. S. A . Baynes (1964) considered it was single-brooded in the northern half of Ireland and double-brooded in the southern half. Today it regularly produces two generations in some counties in Northern Ireland and three in southern areas, including along the Dublin coast.

Warmer summers appear to be assisting the Marsh Fritillary butterfly, which is usually highly sedentary, especially in wet, cool summers but it will move beyond its colony in warm, dry summers, which was very evident during 2018. The species exists in many areas in a metapopulation, meaning it moves around in the landscape, repopulating sites lost during poor years. To function in this way, the species needs warm weather. Cold May and June weather can destroy colonies, so earlier springs and warmer summers may be an advantage to this endangered butterfly.

But there is always a ‘but’. Warmer drier summers and milder, wetter winters may damage some species even if these conditions benefit others. Take the example of the Small Blue, an endangered butterfly that breeds on one species plant, Kidney Vetch, that only grows in usually poor, well-drained thin and skeletal soils such as on fixed and eroding sand dunes and limestone grassland. These soils dry quickly after a few weeks of hot, sunny weather and the foodplant often desiccates, leaving it useless for breeding. Even more worrying is rising sea levels that can remove coastal dune habitats that are the main stronghold for this tiny butterfly. This is already happening along the east coast, notably at Portrane in Dublin.

More subtle changes are created by climate warming that challenges the survival of butterflies. Milder, wetter winters and earlier and warmer springs prompt plants to remain green and begin growing earlier. While this appears to be good news for some butterflies, this can prevent larvae of some butterflies from developing at an optimum rate to cut down on losses due to natural predation or may prevent some developing, starving to death on their healthy foodplants.

This paradox of heat-loving butterflies declining under a warming climate can be explained by the need of many butterfly and moth larvae for an abundance of dry, senile plant matter which is used for basking to raise their body temperature, allowing for food digestion. This is extremely important for larvae that resume feeding in early spring when air temperatures are low. This problem may be behind the crisis afflicting the Wall Brown, now in freefall across most of Ireland. It has not been seen in Northern Ireland since 2015 and is missing from most areas where it was present before the mid-1980s. I suspect this issue may be influencing the decline of the Small Heath too, for like the Wall Brown the caterpillars are daytime feeders that bask on dry, non-growing plant matter to digest their green food.

The increasingly rapid growth of the larval foodplants creates a shading effect, decreasing ground temperatures, making basking on dry stalks or bare soil impossible (if bare patches will persist for long enough under moister, warmer conditions) unless the caterpillar moves away from the plant which many larvae are reluctant to do.

The constraints on the larval micro-site temperatures may eventually be overcome if climate warming creates air temperatures that are warm enough to allow the larvae to reach the correct body temperature without the need to bask on dry, warm material. However, this is not certain either. One of the drivers of climate warming is the increased level of Carbon Dioxide. This may be affecting foodplant quality.

This is an interesting area of study, and the body of literature on this topic is increasing. At this stage, the picture emerging is that winners and losers will emerge under a warming climate scenario. A study in Germany by Habel et al. entitled Butterfly community shifts over two centuries that tracked butterflies on a dry calcareous grassland site overlooking the Danube from 1840 to 2013 found that changes in the environment associated with industrialisation and climate change are benefiting habitat generalists, especially those that use nitrogen-loving plants and damaging habitat specialists that use plants that are adapted to a low nutrient environment.

However, in Ireland and Britain, we have seen some species that were generalists or that occurred in a broad range of habitats become specialised on a smaller number of habitat types. To add to the mix, one butterfly in Britain, the Brown Argus, that was a habitat specialist has become adapted to a broader range of habitats, a development attributed to the warming climate which has allowed it to exploit foodplants that previously were unavailable because they grow in habitats that were previously to cool for it.

The story told here is a developing one. We can expect colonisation by some species, and some of our current species breeding at higher altitudes than they do now. These are likely to be habitat generalists that are following their climate envelope. What is the future of our habitat specialists, which are generally much rarer? We certainly need to protect their habitats and we need butterfly records to let us know what is happening. We don’t want to lose the plot of this tale. Send us your records, both your casual records and, if you can give the commitment, monitor the butterflies in your garden.

Here is how to provide these records, which will be published on our website and sent to a national database. Send your butterfly and moth records to us by email at conservation.butterfly@gmail.com.

Let us know: your name/s, date of the find, species found, the life stage/s found, the numbers seen, the location the butterfly/moth was found (e.g., townland name, site name, county), and a six-figure grid reference, including the letter identifying the 100,000-metre grid square in which the location lies (see http://www.gridreference.ie/ or Discovery Series maps) weather conditions and any other interesting comments you wish to provide.

Example:

John Smith (14/06/2020)

Small Blue 14, Small Heath 15 at O 254515, Portrane sand dunes, County Dublin. Sunny, light breeze, 18 Celsius.

It will be greatly appreciated if you could send in their records by listing the butterflies observed in the following order:

Small Skipper, Essex Skipper, Dingy Skipper, Common Swallowtail, Wood White, Cryptic Wood White, Clouded Yellow, Brimstone, Large White, Small White, Green-veined White, Orange-tip, Green Hairstreak, Brown Hairstreak, Purple Hairstreak, Small Copper, Small Blue, Common Blue, Holly Blue, Red Admiral, Painted Lady, Small Tortoiseshell, Peacock, Comma, Pearl-bordered Fritillary, Dark Green Fritillary, Silver-washed Fritillary, Marsh Fritillary, Speckled Wood, Wall Brown, Grayling, Hedge Brown/Gatekeeper, Meadow Brown, Ringlet, Small Heath, Large Heath, Monarch.

To count the butterflies in your garden, download our Nation Butterfly Garden Survey form below which explains how to record your garden butterflies. We will send you a report at the end of the year after you send us your survey forms.

National-Garden-Butterfly-Survey

A climate change winner, the Comma butterfly. Photo J.Harding
Small Heath butterfly, a victim of agricultural intensification and possibly a climate change casualty. Photo J.Harding
The Swallowtail may colonise Ireland if climate warming continues. It breeds on a range of plants, including Rue (garden herb), Fennell (mainly a coastal plant, also a garden herb) and Wild Carrot (widespread). Photo J. Harding

Annual Report 2020

The rain, wind and misery of January hang heavy on most people, especially on butterfly lovers, who miss the sunshine and happiness inseparable from butterflies. While we wait for better weather to renew our relationship with nature, it is nice to catch up on some reading. A good backdrop to the coming season is Butterfly Conservation Ireland’s Annual Report 2020, now available under the Report tab on this website. The hard copy of the report is free to members of Butterfly Conservation Ireland and will be posted soon. The report is available to non-members at €15.

We hope you enjoy our report and find plenty to interest you. If you have any question or inquiry don’t hesitate to contact us by email at:

conservation.butterfly@gmail.com

or by post:

Butterfly Conservation Ireland, Butterfly House, Pagestown, Maynooth, County Kildare

We bring news of Ireland’s butterflies in our report but we also feature butterflies from faraway. This year we look at the butterflies of South Korea, in a special report brought to us by Michael Friel and Dongjun Cha. This lovely butterfly is Indian Awlking Choaspes benjaminii, related to our skipper butterflies.
Our report mainly tracks the fortunes of our native butterflies, such as the iconic Red Admiral. Like the Barn Swallow, the Red Admiral spends the summer and early autumn months here, but its winter quarters are found in warmer areas in southern Europe.

Good News

After decades of removing peat from our bogs and contributing to biodiversity loss, water and air pollution and rising CO2 emissions, Ireland is moving to biodiversity enhancement, pollution reduction and carbon sequestration. A significant step towards these objectives was taken in November when the government announced a €108m fund to add to €18m provided by Bord na Móna to rehabilitate 30,000 hectares of peatland, with more to follow.

The bog rehabilitation will involve re-wetting bogs that have been drained or cutover (a cutover bog is a bog that has been drained and has had its characteristic vegetation removed along with some of its peat).  Drains will be blocked, ditches filled in and peat profiling carried out to slow water movement on the bogs and promote the development of the bog-building sphagnum mosses which will act as carbon sinks. Among the key goals and outcomes are as follows.

Rehabilitation will support the National Policies on Climate Action and GHG mitigation by maintaining and enhancing the current condition peat storage capacity of the bog (locking the carbon into the ground). In time, it is expected that the bog will develop its carbon sink function, in part, as Sphagnumrich communities develop across the bog. It will also support Ireland’s commitments towards the Water Framework Directive, the National Biodiversity Action Plan and the National River Basin Management Plan 2018-2021. (Source: Bord na Móna Draft Rehabilitation Plan 2020).

Bord na Móna workers who previously worked in peat ‘harvesting’ will be working to restore the bogs. Walking tracks, trails and other amenities will also be constructed in certain parts of the boglands, while efforts to protect biodiversity will begin. Other peatlands will be rehabilitated outside of Bord na Móna’s landholding and it is cooperating with the National Parks and Wildlife Service to expand this operation into third-party lands over the next decade.

It is expected that work to restore peatland habitats will begin next April.

While this is very positive news, the expectation is that the natural processes involved in rehabilitating the habitats will take a long time, especially on some cutover bogs. However, Bord na Móna is confident that this can be achieved over time, but warns that “it will take some time (30-50 years) for naturally functioning peatland ecosystems to fully re-establish. ” (Source: Bord na Móna Draft Rehabilitation Plan 2020).

The prospect of bog restoration, of seeing Large Heath and Green Hairstreak butterflies and Emperor moths, of hearing the Curlew and Skylark, of smelling the sweet intoxication of heather in August, is indeed exciting.

We urge people living in the midlands to engage with the newly restored bogs, by walking on the tracks and trails provided, by photographing the habitats and wild creatures and publicising the wonderful worlds that bogs offer. Bogs need exploring carefully; their wildlife treasures do not always yield themselves to casual observation. Butterfly Conservation Ireland will be delighted to post these images on our website and Facebook page.

Butterfly Conservation Ireland has written to Bord no Móna with suggestions on how the progress of bog rehabilitation might be measured.  The presence of the endangered Large Heath butterfly is indicative of the quality of the rehabilitation undertaken because the butterfly only exists on wet bogs. Its larval host-plant, Hare’s-tail Cottongrass Eriophorum vaginatum, dies when the surface of a bog dries but the plant is frequent when the bog’s water table is at or close to the surface. This plant needs to be abundant on the bog for the Large Heath butterfly to survive. We suggested that vegetation monitoring planned by Bord na Móna assesses the density of the Hare’s-tail Cottongrass and Cross-leaved Heath Erica tetralix, the latter plant being the chief nectar source for the adult Large Heath, against the density on intact bog sites containing abundant populations of the Large Heath.

We also urged that no future use that compromises the conservation value of any rehabilitated peatland is considered. We also recommended that publicity material be generated to showcase the biodiversity benefits achieved by the rehabilitation undertaken at the various bogs. This will support Bord na Móna’s “naturally driven” philosophy and generate considerable positive publicity to highlight Ireland’s commitment to tackling biodiversity loss, pollution and climate change.

More needs to be done to protect bogs, and urgently, as many protected bogs or areas of protected bogs in private hands such as Mouds Bog, County Kildare, among many others, are still being destroyed. We need to extend climate action and biodiversity action policies to all peatlands, not just a few.

However, we commend the Irish government on the steps taken to cease peat exploitation on Bord na Móna bogs. A lot done, but more to do.

See https://www.gov.ie/en/press-release/2aae1-cabinet-approves-108m-funding-for-groundbreaking-bord-na-mona-bog-rehabilitation-plan-minister-ryan-also-announces-that-47-more-projects-in-the-midlands-totalling-278m-are-approved-under-the-just-transition-fund/

Update on December 14th post

In January 2021 Bord na Móna announced that it has ended turf cutting throughout its estate.

Making the announcement, Bord na Móna Chief Executive Tom Donnellan said: “The Brown to Green strategy has involved the transformation of Bord na Móna from a traditional peat business into a climate solutions company. The progress made over the past two years means we are now fully focused on renewable energy generation, recycling and the development of other low carbon enterprises. While there are many advantages to the changes we have made, the key benefits include the high value, sustainable employment we are providing and the significant support we are delivering to Ireland’s objective, to become carbon neutral by 2050.

As we have put our new climate-focused business in place, we have also completely stopped a number of high carbon operations and transitioned others to a more sustainable model. During this period, peat harvesting has already been wound down and stopped. The company’s last full peat harvest took place in 2018, followed by a partial harvest in 2019 and a full suspension of harvesting operations last year. The company has today decided to make this suspension permanent and cease any remaining harvesting preparations, including planning and substitute consent applications. Today marks the formal end to the company’s association with peat harvesting, as we move on to tackle the critical challenges concerning climate change, energy supply, biodiversity and the circular economy.”

Butterfly Conservation Ireland warmly welcomes this development. We want to see the end to all peat cutting on Bord na Móna land, including cutting by operators with contracts with Bord na Móna to cut peat on Bord na Móna land.

Some bog beauties follow…

Common Darter. Photo J.Harding
Red Admiral Photo J.Harding
Green Hairstreak Photo J.Harding
Eyed Hawk-moth.©J.Harding.
Marsh Fritillary. Photo J. Harding.
Marsh Fritillary Photo J.Harding
Emperor Moth  Photo J. Harding
Some rehabilitated areas will contain flooded areas that will provide habitat for wetland plants, birds and aquatic animal groups such as amphibians and dragonflies. Photo J. Harding

 

Where does our environment stand now?

It is late November 2020 as we near the end of the second decade of the second millennium. It is time to ‘take stock.’ How are our precious habitats and wildlife populations coping with our behaviour?

Let’s see what Ireland’s Environmental Protection Agency (EPA) has to report on the state of Ireland’s precious habitats

Listening to the EPA Director General Laura Burke on RTE Radio 1’s Morning Ireland on Wednesday 25th November, we are performing poorly.

Some headline statistics underscore the deterioration in the quality of our surroundings. We have 20 pristine rivers today compared with over 500 in the 1980s. Raw sewage is being discharged to water from 35 towns and villages. 90% of Ireland’s energy is still being generated from fossil fuels; air quality in some urban areas does not meet World Health Organization standards.  85% of Ireland’s EU-listed habitats are in an unfavourable condition.

These habitats are legally protected, but this is rarely enforced. Just look at Mouds Bog, County Kildare (among many other ‘protected’ bogs), being ravaged by illegal drainage and peat cutting while the body charged with protecting these habitats, the National Parks and Wildlife Service (NPWS), stands idly by, watching it all happen. And doing absolutely nothing to stop this, other than producing bland letters describing various (meaningless) policy initiatives to protect rapidly vanishing peatlands.

Dealing with habitat protection is not a resource issue for the NPWS, it is a problem of identity, leadership and culture. As for identity,  the NPWS is not an agency or even a single body – lately, it sits within the heritage division of the Department of Housing, Local Government and Heritage, alongside the National Monuments Service and Built Heritage, Architectural Policy and Strategic Infrastructure. As for leadership, there is no head of the NPWS as such; responsibility ultimately lies with the minister of the day. The culture within the organisation means that it is ill-suited to its task. I once made 11 phone calls to a range of phone numbers to report suspected damage to a protected site before I received an answer to the call. When the appropriate person made contact, several days later,  I was told that their phone was out of range. This I knew to be untrue, and I made this known. An embarrassed silence followed.

The officer did make a site visit and all was well, thankfully, but the issue was not processed in a timely manner. Non-governmental organisations like Butterfly Conservation Ireland should not need to insist that our environmental laws are upheld. The NPWS exists to fulfil this function, among others.

Sticking with the NPWS function to defend habitats that have legal protection, there are some excellent NPWS staff absolutely committed to their roles.  These men and women do excellent work, using their powers to protect our environment. They get little or no encouragement from within the organisation, and some may feel isolated and vulnerable. The sense is that there is little chance of promotion for zealous conservation officers. This conveys a dysfunctional culture and leadership failure-in such cases, one is relying on people of honour to do their jobs properly. Luckily, NPWS has such caring, brave staff.

For the sake of the tawdry remnants of our bogs, let us hope that NPWS continues to have their service. But more of these dedicated people, and overall reform and serious will, is needed.

Ireland has a reputation for having a clean environment. The new EPA report shows that this is undeserved. The state signs up to various environmental commitments and then largely ignores delivering on them. Thus, the state agreed to the European Union Habitats’ Directive as a European Union member state and designated Special Areas of Conservation and Special Protection Areas. Some features (known as qualifying interests)  used to identify Special Areas of Conservation, such as the presence of particular species, now no longer exist on a number of the designated sites, due to site deterioration arising from illegal damage and or bad management.

Such deterioration may lead to call for the site to be delisted as a protected site-it is hard to see how some raised bogs can remain on the protected list after the damage done to them. A cynic might say that this is how the state hopes to evade its responsibilities to protect these delicate sites.

If that is the plan, it is working.

Raised bogs are on the brink of extinction in Ireland, thanks to a refusal to protect them.
The Large Heath butterfly lives nowhere else except on wet bogs. Its future in Ireland lies in our hands. Photo J. Harding.

 

 

What is flying in November

The clocks have moved back an hour, sounding the death knell for Irish summertime. In truth, the summer left us some time ago. Time: the indefinite continued progress of existence and events in the past, present, and future regarded as a whole.

One of time’s markers is the appearance of the species of butterfly and moth because each species has its slot or slots in the year. For those on intimate terms with our species flight times, we can mark the seasons according to the emergence of butterflies and moths. Sometimes we are surprised. Every so often, we see a species when we shouldn’t.

In February, statistically our coldest month of the year, we don’t expect to see Brimstone butterflies. On 25th February 2019, Pat Wyse recorded nine Brimstone butterflies in Lullymore and Lullybeg, in County Kildare. We had an unusually balmy week and Brimstones woke early. But they looked out of place. Their breeding plants were not ready. Luckily, early dandelions provided nectar. Other records of early butterfly sightings flooded in.

The early opening to the Brimstone flight season did not do the butterfly any harm judging from the large generation that flew later in the year.

However, the Brimstone can appear at odd times because it exists as an adult butterfly for most of the year. In fact, it can be seen in any month, although it is abundant mainly in April/May and August. But to see it in February is very unusual and requires unusually warm, sunny weather.

The year 2020 had early emergence dates for spring butterflies but afterwards the weather dipped, giving us more typical flight times for summer and autumn flyers. We are having a mild autumn and there are still butterflies and moths flying.

The Comma is still on the wing and is feeding on ivy blooms and late flowers in gardens. At this time of year, it will spend long periods basking on warm, dry surfaces, such as bare earth, tracks, tree trunks and garden decking. Stephen Lawlor has sent in the lovely photo of a Comma basking in his garden. It looks especially beautiful in autumn sunlight-when seen in the flesh, it has an incredible glow, a stirring warmth to excite the eye.

The odd Small Tortoiseshell is being seen. George McDermott has seen the species in Donegal, taking nectar on late-flowering  Perennial Wallflower  ‘Erysimum Bowles Mauve’. A few Red Admirals are still out there; indeed, they are still breeding in Howth, County Dublin, where Frank Smyth keeps a close watch on their development over the colder months of the year.

Last night I saw my first December moth of this season, a male twitching his feather antennae under an outdoor light. Usually, I see this moth later, at the end of November and during December. Check under outdoor lights during mild nights for this species.

The lovely Red-green Carpet is flying now, but you really need a light trap to attract this species. The moth mates in autumn but males die, with the mated females entering hibernation. At this stage, the moths feed on ivy flowers. When the females wake in spring, they feed on sallow catkins.  They will lay their eggs on birch, lime, oaks and other trees and shrubs.

The well-named November moth is flying too-a cryptic grey moth flecked with black. Yellow-line Quakers, also requiring light traps to be found, also occur during November; again ivy flowers are used for feeding. These two species leave their eggs behind before the adults die. The eggs of both species are laid on native trees such as oak, birch, hazel, hawthorn and others.

However, these species represent a late flowering. Soon, apart from a small number of winter specialists, we must wait until spring to see the glow of butterfly wings in flight.

Start getting your garden ready for spring!

Comma basking. Photo Stephen Lawlor.
Red-green Carpet. Photo J.Harding.
Small Tortoiseshells can fly well into November. Photo J.Harding.
November moth. Photo J.Harding.
Red Admirals will breed even in winter in mild coastal areas. Photo J.Harding.
December moth. Photo J.Harding.
Small Heath caterpillar. Photo J.Harding. The Small Heath caterpillar is very difficult to find in the wild. The caterpillar will feed during the day throughout the winter during mild, sunny weather. The caterpillar in this photograph is c.8mm in length and is in the fourth of five instars.