Lullybeg Reserve, County Kildare, March 2020. Photo J.Harding
Purple Moor-grass is the dominant grass over much of Butterfly Conservation Ireland’s reserve at Lullybeg, County Kildare. In autumn, the grass changes to a bright bleached colour. This makes the site especially wintry in appearance.
However, spring is stirring on this apparently dead grassland. And it is this dead grass litter that helps kick-start life into action. At this time of year, this grass dries out and heats up very quickly. Warmth rises from this straw-like grass. And caterpillars depend on this for their development.
Caterpillars feed on live leaves, including larvae that feed on grasses. However, eating food and digesting it are very different processes. A caterpillar must raise its body temperature to activate the digestive enzymes.
In the photos below two species are basking on the leaf litter. The massed larvae are the caterpillars of the rare and beautiful Marsh Fritillary butterfly, a beautifully patterned creature whose habitat enjoys protection under European Union legislation. One of the reasons it is so rare is that it must have very specific habitat conditions. Among its requirements is a high density of the caterpillar foodplant, Devil’s-bit Scabious growing among vegetation that contains dry leaf litter in spring. Lullybeg ticks this box.
The site is very carefully managed to ensure that these conditions are maintained. Today, I counted the Marsh Fritillary nests (the larvae live in groups from the time they hatch in July until late in April). Some of these nests, happily, hold hundreds of little caterpillars which help to heat each other when they sun themselves in a bristly black mass. We have a thriving population here, thanks to all the support from our members. It is great to know that we can make a difference to rare species. We are delighted to be able to report that 49 nests of the Marsh Fritillary caterpillars have made it through the winter. Thank you!
The single caterpillar is the larva of one of our largest moths, the Fox Moth. This caterpillar will not feed again. It spends some of the spring basking on dry grass before pupating. It flies in May and June.
Other larvae present at Lullybeg, such as the Small Heath butterfly’s caterpillar, also need dry, dead leaf litter among its green food. Feeding only in daylight, this caterpillar also shares the need for warmth and dryness.
So while the photo appears to show a ‘dead’ scene, it is anything but!
A final piece of news: the Great-spotted Woodpecker has arrived at Lullybeg. A bird was drumming on a tall tree. What a lovely way to announce spring.
Marsh Fritillary larval nest, Lullybeg, County Kildare. Photo J.HardingFox Moth caterpillar basking in advance of pupation. The adult moth, which does not feed, flies in May and June. Photo J.Harding
Continuing with the theme of spring’s onset, we can ‘see’ spring coming when certain signs appear to signal the season’s arrival. People often have a particular, personal spring sign. For some it is birdsong. The Hedge Sparrow is singing now; it is a drab little bird but a persistent singer (https://www.youtube.com/watch?v=G5ptciy2AuA). For others, it is the emergence of frogs to spawn in ponds. It might even be the emergence from hibernation of a fairly obscure creature, like the Smooth Newt. I know of a newt population that dwells in a hot spring. These newts become active in January, but that doesn’t count! April is more usual. For other people, it is the appearance of spring flowers, especially the Primrose on hedgebanks, a stirring and happy sight. Who doesn’t like a Primrose?
Some people like them too much. ‘Primrose trains’ carrying less wealthy Londoners into the countryside in the early decades of the twentieth century saw mass picking of the flowers to brighten homes and gardens in London. Today we often buy cultivated primrose plants from garden centres, which is a pity as the authentic wild plant is easily propagated from seed sown fresh.
Butterfly lovers keenly await their first butterfly of the year. I still wait for my first sighting. I nearly succeeded but was a day too early-I saw a Peacock on December 31st! There is folklore in some countries, especially Scandinavian cultures which holds that if your first butterfly of the year is yellow you will have a wonderful summer. According to Matthew Oates, the first butterfly sighted in England in 1976 was a male Brimstone, a beautiful yellow butterfly, and what a summer that was! Unfortunately, in Ireland (as in England), the Brimstone is the only yellow butterfly we have so the chance of seeing the Brimstone as our first is not high. Our first record of the glorious summer of 2018 was a Small Tortoiseshell on January 5th the sighting of which is also, apparently, a positive sign. According to folklore, a sign of a bad summer is seeing a Peacock or Red Admiral as the first butterfly of the year so we hope to avoid these as our first sightings. Perhaps it is fortunate that I did not see that Peacock on January 1st!
Last night (March 17th) we had some heavy rain but mild conditions. Many moths, unlike butterflies, don’t mind rain, even heavy rain, as long as it is mild. When I inspected the moth trap in the morning I found five species, all typical of early spring. These are all muted in colour, unlike the far more colourful moths found in June and July when vegetation is well-developed and there are plenty of hiding places. However, these are our first free-flying species of the year, making these a warmly welcome sight.
Early Grey, an aptly-named moth, appears from March-May. This moth can sometimes be seen by day, settled on grey limestone walling until night returns.The Hebrew Character flies from March to May. It breeds on native trees, such as oak, birches, willows as well as Bilberry, Meadow-sweet and Common Nettle. The moth is named after the black mark on its forewing that resembles the serif version of the Hebrew letter ‘nun’, the equivalent of our ‘n’. This moth is abundant, providing a vital food source when its larvae are available to foraging birds.The Clouded Drab is also a March to May flyer and also breeds on a range of deciduous trees. It is undeniably plain but seeing it in spring makes it a sign of a return to vitality and natural abundance.The Early Thorn flies from mid-February to May and again in a second generation from July to September. This species depends on native trees for its breeding requirements. Its sharply pointed forewing bears the appearance of a thorn. This individual remained on the wall of an out-building all day. A foraging Wren failed to identify it as food-the thorn impersonation works.The Common Quaker flies from March to May. Oaks, willows, birches, Common Hazel and Common Hawthorn are breeding plants. This species is very numerous in moth traps and its larvae which feed in spring and summer must be a vital food for breeding birds. Its plain colouring explains its name as the early Quakers wore sober, unpretentious garments.
The weather is set to show improvement. The next few days and the week ahead are forecast to be mainly dry with some sunshine. We need sunshine in our lives, especially now. Add butterflies and birdsong for extra happiness.
Send us any records (see https://butterflyconservation.ie/wp/records/) and photos (especially of moths and butterflies) to share your happiness!
Nothing is so beautiful as Spring –
When weeds, in wheels, shoot long and lovely and lush;
Thrush’s eggs look little low heavens, and thrush
Through the echoing timber does so rinse and wring
The ear, it strikes like lightning to hear him sing;
The glassy peartree leaves and blooms, they brush
The descending blue; that blue is all in a rush
With richness; the racing lambs too have fair their fling.
The English poet Gerard Manley Hopkins 1844-1889 is renowned for a poetic technique known as sprung rhythm. This technique gives his work vibrancy, fitting for a poem about so uplifting a season as spring. In this verse, a vision of heaven on earth, we see him celebrate the power of spring. In his opening line, Hopkins is emphatic: “Nothing is so beautiful as Spring”. There is no equivocation, no doubt! It is the best time of the year. This entrenched position is buttressed by a wonderful array of examples; weeds, not flowers, are mentioned, underlining his celebration of the ordinary! The weeds, “shoot long and lovely and lush”. Hopkins use of alliteration in ‘W’ and ‘L’ and the assonance of ‘ee’ sends the imagery leaping skywards, helping us to visualise the galloping growth of springtime herbage. This eye-catching imagery is continued in the sky-blue Song Thrush eggs, a stunning sight for any nature lover. We see the “glassy peartree leaves and blooms”, a dazzling spectacle; the blue skies reach down to the earth (“descending blue”) to link heaven and earth. The verse closes with the charming innocent exuberance of spring lambs, reminding us of innocence and enjoyment of life’s simple goodness.
The American poet Robert Frost 1874-1963 loved spring too. Here is the first verse of his poem, A Prayer in Spring.
Oh, give us pleasure in the flowers to-day;
And give us not to think so far away
As the uncertain harvest; keep us here
All simply in the springing of the year.
Emily Dickinson 1830-1886 clearly loved spring too. Here is the first stanza of her poem, A Light exists in Spring.
A light exists in spring
Not present on the year
At any other period.
When March is scarcely here.
In both verses, spring is lauded for its uniqueness. Frost wants to live forever in the moment that is spring. Dickinson delights in spring too but characteristically for her, she admits that it will not last:
A quality of loss
Affecting our content,
As trade had suddenly encroached
Upon a sacrament.
Yet its transience should, and does, sharpen appreciation of this exciting time. We all have our vision of what spring means to us. We might even remember particular years for their lovely springs. We might even cherish a memory of a perfect spring day. One of my special spring days is March 25th 2017. The place, Lullybeg, County Kildare. Frost was sublimated by the beaming March sunshine. Ethereal vapour shimmered in lucid sunlight as the cold dissipated. Into this warming air fluttered my first sulphur-coloured Brimstone of the morning and just the second time I’d seen the butterfly that year. As the heat dried the vegetation, the fragrance of spring suffused tranquil birdsong-filled air. Caterpillars sunned themselves. By midday, in a sheltered clearing created by Butterfly Conservation workers during the previous autumn and winter, Brimstones danced around their caterpillar foodplant, Alder Buckthorn.
The Brimstones, fluttering around leafless apparently barren Alder Buckthorn shrubs make a surreal sight. The Alder Buckthorn, a mundane sight when leafless, has spindly charcoal twigs. I watched the butterflies chase and evade mates, bask, feed and lay eggs. Females are paler than the daffodil-yellow mates and when perched on twigs depositing eggs, their backlit wings, large as a child’s hand, are mirage-like. The bare buckthorns give the Brimstones your full focus. Their dance was day long, making a dream day. I stayed all day until the butterflies roosted. The sun, the light, the happy sound of bees, birds, the smell of the awakening world and feeling part of this intense life is happiness for now and the future. This moment still replays in the memory. I hope to top up that memory this spring.
The Brimstones hide through six months of cold, wet and darkness to launch themselves into the sparkling spring sunshine. More than any other butterfly, the Brimstone lets you know that spring has arrived. Unlike the over-wintering nymphalid trio of Small Tortoiseshell, Peacock and Comma, the Brimstone can only be active during sunshine. With its brightness and happy, flopping flight the Brimstone is pure joy. The Brimstone deserves a poem. Poet Liza Jones agrees.
I pen a Brimstone lullaby,
Poet tease: poetise: Morpheus arise!
Inky white of cryptic wing
Sulphur tinged tips, inscribed: shimmering!
Poet eyes: Tantalise!
I versified on relenting brimstone.
I ken a Brimstone Butterfly
Silken purse defied! Honed,
Evangel-wings emerging this spring,
A Yellow flier of coaxing charms
Milky, musky, butter balm,
Flowing tenor up whirring
Shropshire’s’ downs, confetti showering,
I ken a Brimstone butterfly, flutterby.
These are uncertain times, of that there is no doubt. But joy is not off-limits. A walk in the open air this spring will still do you good. In the words of William Wordsworth, “Come forth and feel the sun”.
Why not let us know what you see? You can contact us with your butterfly records by emailing conservation.butterfly@gmail.com. See our Records page (https://butterflyconservation.ie/wp/records/) for the information we need to validate your record. We will publish your butterfly/moth record on the 2020 page under the Records tab. If you are not sure what butterfly or moth you’ve seen, send us a photo or check our gallery: https://butterflyconservation.ie/wp/gallery/
The first butterfly reported to Butterfly Conservation Ireland in 2020 is a Peacock near Minane Bridge, County Cork on February 27th. The butterfly in this photo was seen on March 5th in the same area. The Peacock in this photograph is clearly in need of warmth. It is basking on a rock, absorbing heat mainly from the surface of the rock. It obtains a minority of the heat from the direct sun shining on its upper wing surfaces.
In early spring, Peacocks rarely spend long in the open. The butterfly basks and feeds, remaining close to its hibernation site. When it gets cool, the butterfly will return to its resting place. It will not stray far until there are some days of sustained warmth and sunshine. When conditions become consistently warmer, the Peacock departs to find food and breeding sites.
Good areas to look for Peacocks during March are sunny rides and clearings in woodland. When the days lengthen, the Peacock will be found in more open areas where it can be found in company with its close relative, the Small Tortoiseshell, another butterfly that passes the coldest months as an adult.
The appearance of these colourful butterflies is a great tonic after a bleak and tempestuous winter. To help them, allow your willow to flower, do not cut flowering dandelions and provide extra nectar in the form of native primroses and non-native flowers such as grape hyacinth Muscari neglectum. Nettle patches should be allowed to develop in warm, sunny areas to encourage breeding.
Finally, let us know of your sightings by emailing us at conservation.butterfly@gmail.com with the following information:
your name/s,
date of the find,
species found,
the life stage/s found,
numbers seen,
location the butterfly/moth was found (e.g. townland name, site name, county),
six-figure grid reference, including the letter identifying the 100,000-metre grid square in which the location lies (see https://irish.gridreferencefinder.com or Discovery Series maps)
weather conditions
and any other interesting comments you wish to provide.
Example: John Smith, 14/06/12, 14 Small Blues, 15 Small Heaths, Portrane sand dunes, O254515, County Dublin. Small Blues feeding on Kidney Vetch and Creeping Thistle. Sunny, light breeze, around 18 degrees Celcius.
It will be greatly appreciated if you are sending in your records of several species 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.
These records will contribute to a national butterfly atlas which will cover the period 2017-2021. This should provide a clearer indication of how Ireland’s butterflies are performing in an era of profound change.
A slate grey sky, sharp persistent westerly wind with the threat of a deluge usually discourages outdoor effort but not for our optimistic and committed members. And as for rain, it stayed dry throughout our workday.
We targetted an area of scrub that we knew contained some fine specimens of Alder Buckthorn. If we could clear the surrounding scrub we would make the Alder Buckthorn available for breeding by Brimstone and Holly Blue butterflies as well as the range of bees that are obsessed by the unexpectedly rich nectar the plant’s tiny flowers provide.
A great effort was made. Five hours later we had a great clearing made. We kept sufficient scrub to give shelter to the buckthorns while allowing light to reach the area. An old pond, which I last saw around 20 years ago, was still there. Perhaps the frogs will return to breed there in the next few weeks.
Another butterfly that we hope will benefit from our work is the Dark Green Fritillary, which is very rare in Kildare, Meath and many other counties, especially counties lacking a coast. The violets in the clearings which grow in patches among dry grass leaf litter offer promising breeding opportunities to this dynamic, beautiful butterfly. We’ll see if this happens in June/July!
Thanks to all who braved the elements. There is strong camaraderie on our workdays with conversation and lunch making the work so much sweeter!
An Alder Buckthorn plant now available for the Brimstone butterfly.A cleared area at Lullybeg, County Kildare.
At this time of year, day-length is increasing and the angle of the sunlight is reaching further indoors. The light is reaching tucked-up butterflies, rousing them and causing them to appear at windows.
No matter how energetic the butterflies are as they toss themselves against the glass, it is not the time for their release. It is bitterly cold, wet and occasionally stormy this February and there have been no records of wild free-flying butterflies so far this year. This weather may continue into March.
Place any butterfly that has awoken in your home in a glass jar, lined with a kitchen roll. You can place more than one butterfly in the jar. Place in the fridge and release only when there is a warm, settled spell, usually from late March. I have over-wintered a Small Tortoiseshell until mid-May. It flew energetically away, apparently none the worse for its extended rest.
Not all butterflies survive, even when the recommended measures are used. It is likely that these casualties arise from insufficient weight gain pre-winter or loss of weight during the winter when fat reserves are wasted flying indoors for a prolonged period.
Owing to the volume of inquiries this winter, we will advise when to release the butterflies.
Here is a photograph of two Small Tortoiseshells on kitchen roll in a glass jar that I am over-wintering in my fridge where the temperature of four Celsius is ideal to keep them dormant.
Small Tortoiseshells being over-wintered in the fridge in a glass jar with the lid removed for this photograph. Line the base of the jar with kitchen roll for the butterfly to perch on and to absorb any excess moisture. Photo J. Harding.
From the state of Michoacán in Mexico comes the sad and disturbing news of the violent deaths of two butterfly guides, Homero Gómez and Raúl Hernández who were protecting the Oyamel fir forest habitat of over-wintering Monarch butterflies.
The Oyamel fir forest is a Monarch butterfly forest located in part of Michoacan, Mexico and Mexico City, Mexico. Billions of butterflies migrate from Canada and the United States to Mexico to hibernate during the winter. The clusters of Monarch butterflies bedecking tall forest trees with their orange wings is one of the greatest natural sights on Earth. Their migration constitutes “70% of the total overwintering population of the Monarch butterfly’s eastern population” (UNESCO, 2013), becoming one of the most dramatic and spectacular migrations of all insects. The monarch butterfly has an important value to the environment and the culture. Because of the number of Monarch Butterflies migrating, they are one of the greatest pollinators in America (Taylor, 2009).
Oyamel fir forest has been illegally logged, therefore the ecosystems and the Monarch butterflies are under threat. The World Wildlife Fund data reveals that “[a]ccording to a survey carried out during the 2012-2013 winter season by the WWF-Telcel Alliance, and Mexico’s National Commission of Protected Areas (CONAP), the nine hibernating colonies occupy a total area of 2.94 acres of forest—representing a 59% decrease from the 2011-2012 survey of 7.14 acres. The migration of these insects is endangered to extinction threatening the equilibrium of the continent’s environment.
Homero Gómez, one of best-known guardians of the monarch butterfly in Mexico and a leader of the ejido (a Mexican cooperative system of community and shared ownership) disappeared on January 13. Mr Gómez’s body was found in a well on 29 January. The state attorney has stated that the death was an accident. Officials initially said his body showed no signs of violence, but a post mortem examination revealed he had suffered a blow to the head before drowning in the well.
However, a second guide, Raúl Hernández, 44, disappeared on Monday 27 January. His body was found six days later at the top of a hill in the El Campanario Monarch butterfly sanctuary. Forensic experts said his body was covered in bruises and he had a deep wound to his head. An investigation into his death is underway.
Conservationists fear his death may be linked to that of Homero Gómez. Gómez’s family said that prior to his disappearance, the activist had received threats warning him to stop his campaign against illegal logging.
He was a tireless campaigner for the conservation of the Monarch and the pine and fir forests where it hibernates. The sanctuary he managed opened in November as part of a strategy to stop illegal logging in the area, which is a key habitat for the species. He was also involved in reafforestation.
Mexico has serious corruption and criminality problems. In 2019 there were 34,582 recorded killings, the highest rate ever. In Michoacán 53 police officers were detained recently by prosecutors in connection with the disappearance of Gómez. The justice system in Mexico allows offences to go unpunished, with only 3% of murders in Michoacán state solved.
This background of corruption and violence makes the conservation work of Gómez and his community all the more remarkable. He knew his life was under threat yet he refused to be intimidated. Homeo was committed to saving the hibernation habitat of the Monarch and his community’s environment.
At Homero Gómez’s funeral, a handful of monarch butterflies flew into the church in Ocampo and fluttered above the congregation. In Mexican culture, the monarch is considered the soul of the recently departed as its annual return to Mexico coincides with Day of the Dead on 2 November.
His son, also named Homero, says that Homero Gómez firmly held that belief too: “We know he will return in the form of millions of butterflies in November.”
The site management day planned for Fahee North, County Clare on Saturday 15th February has been postponed due to the adverse weather forecast for the weekend. The event will be held in September. Details of the new date will be posted on the Events page when known.
Butterfly Conservation Ireland regrets any inconvenience caused. We hope you can join us in good weather in September.
WHERE DID OUR BUTTERFLIES LIVE WHEN IRELAND WAS COVERED IN DENSE FOREST?
Most of Ireland’s butterfly species and many moths breed on grasslands. Only one shade-tolerant butterfly, the Speckled Wood, can breed on foodplants growing in shady conditions. Even species that breed in woods do not breed under the heavy shade where it is too dark and cold to support larvae.
In the wildwood that blanketed Ireland, how did these species survive?
The pollen record shows that Ireland had tundra vegetation for around 1,000 years after the most recent glacial period which ended 11,000 years ago. Stunted willow and grasses occurred and arctic wildflowers like Mountain Avens flowered in brief arctic summers. Around 10,000 years ago the climate warmed. A succession of shrubs and early colonising tree species appeared, especially juniper and birch. Around 9,000 years ago Common Hazel and Scots Pine appeared and dominated for around 3,000 years. From 8,000-6,000 years ago, oak and elm with ash and yew developed. The first farmers appeared about 6,000 years ago. From 4,500 years ago the first major human impact on the country’s forests began to become evident. By the Early Christian period, around 1,500 years ago, the impact was very evident and by early Medieval times, very little woodland remained.
However, thousands of years of dense, countrywide woodland cover would have made Ireland totally unsuitable for almost all of Ireland’s butterflies-probably only the Purple Hairstreak would have survived in closed-canopy woodland. How, then, did Ireland’s grassland butterflies survive? The answer that has been advanced is that their populations would have been very low, confined to areas that trees could not grow, such as bogs, unstable sand dunes, river banks and on thin soils in upland areas. This view is borne of the necessity to explain how the butterflies survived rather than the suitability of these habitats for the range of species that occur today. Lightning strikes that burned woodland and generated grassland mixed with early successional woodland habitats have also been suggested as providing the habitat needed for survival.
Recently, the view that the post-glacial landscape of Ireland and temperate-zone Europe was heavily wooded has been challenged. Dutch ecologist Dr Frans Vera’s book Grazing Ecology and Forest History (translated into English in 2000) provides an insight into what woods may have looked like. The picture he paints is intriguing. If accurate, it would explain a great deal about how butterflies, moths and many other invertebrates manage to exist in Ireland, Britain and in temperate Europe.
Vera puts forward the view that the landscape was far more open than many believe. Temperate zone Europe, Vera maintains, would have been characterised not by ubiquitous species-poor closed-canopy forest – as is commonly thought – but by a more open form of wood-pasture driven by grazing animals. Europe would, for the most part, have been a dynamic, shifting landscape of open-grown trees, emerging scrub, grazing lawns, groves and thorny thickets. An open wooded landscape like this, with grassy areas forming large clearings, would be ideal habitat mosaic for our butterflies. Butterflies and moths really like the warmth and shelter of wood edges, rides and clearings. Even the bog specialist, the Large Heath, will breed on a bog with scattered trees and scrub.
Vera argues that Europe had a large population of animals such as Beavers, Red and Roe Deer, Elk, Wisent and Wild Boar-similar to the population sizes seen in Africa today. These animals created open areas by trampling, digging, grazing, browsing, de-barking, felling trees and damming rivers (Beavers).
While there are debates and challenges regarding Vera’s theories, there is evidence that he may be accurate about the type of landscape that may have existed before human impact became important.
SAPROXYLIC BEETLES
Dr Keith Alexander, an independent specialist in saproxylic beetles (invertebrates that are dependent on dead or decaying wood (or dependent on other organisms that are themselves dependent on dead wood)), argues that sub-fossil saproxylic beetle evidence has been interpreted – wrongly – to describe a landscape that was, in the past, predominantly closed-canopy forest. In his view, the beetle evidence – when properly analysed – clearly shows the opposite: a landscape characterised by open-grown trees.
For example, species like Dryophthorus corticalis and Prostomis mandibularis, one of the commonest beetles of the Early Holocene (12,000-7,000 years ago), are highly specific and require large girth tree trunks containing volumes of decayed heartwood. Closed canopy conditions do not produce such trees.
Overall, says Alexander, sub-fossil evidence for the early Holocene indicates that 28% of the sub-fossil beetle fauna were grassland and scrub species; 13% arboreal; and 47% wood decay. In the late Holocene, 44% were grassland & scrub species; 11% arboreal; and 34% wood decay. The composition shows very low levels of shade-demanding arboreal species – so while trees are well-represented, shade is clearly scarce. The Late Holocene records indicate increased open grassland and scrub, as well as the presence of early successional mosaic species, which would be expected as humans re-colonised the land and agriculture developed. For both the Early and Late Holocene, predominant open wood pasture is consistent with the data; the closed-canopy forest is not.
CHALK GRASSLAND SNAILS
A similar picture emerges from the fossil evidence of chalk grassland snails. In the late 1990s, just as Vera was completing his thesis, environmental archaeologist and conchologist Dr Mike Allen, a lecturer at Oxford University and research fellow at Bournemouth University, began questioning the prevailing archaeological belief that the chalk grasslands around Stonehenge, Avebury, Dorchester and Cranborne Chase in Wessex were blanketed in postglacial woodland.
The sub-fossil snail record, Allen realised, pointed, instead, to a landscape of open grassland with open-grown fruiting trees and shrubs. It is his work that has informed the stunning visual displays depicting the evolution of the chalk landscape in the new museum at Stonehenge. Herds of grazing and browsing animals kept these savannahs (a savannah is a mixed woodland-grassland ecosystem with an open canopy that allows sufficient light to reach the ground to support an unbroken herbaceous layer consisting primarily of grasses) open, providing habitat for the snails; and it was this open landscape supporting a huge biomass of animals that attracted the early human populations to the area.
LICHENS
The lichenologist Dr Francis Rose, a former lecturer at King’s College, London, had scratched his head over closed-canopy theory from the 1970s until his death in 2006. His work is largely concerned with epiphyte forest lichens and for thirty years he studied them, in particular, in the New Forest (Hampshire, southern England). He noticed that very few species of lichen – or, indeed, mosses or liverworts – could be found inside dense stands of trees. Almost all require light and are found on either open-grown trees or trees along rides and the edges of glades or ‘lawns’.
The survival of relict species of moss and arctic-alpine plants – typical of the habitat of the last glacial period (i.e. before trees returned to our landscape with the warming climate) – on common land in Denmark grazed by horses also convinced Rose of the role of herbivores in keeping areas open of tree cover. Similar Devensian/Midlandian era (last glacial period) habitats in Norfolk, he noted, were vanishing with the abandonment of traditional grazing, and small fen plants like northern bog sedge and butterwort, and various orchids and subarctic type bryophytes were disappearing with them.
CONCLUSIONS AND IMPLICATIONS FOR OUR BUTTERFLY POPULATIONS
While Vera’s views have been challenged there is no doubt that such a situation of open woodland is beneficial to butterflies. Grazing by large herbivores is very important for the maintenance of these habitats and many butterflies would disappear if grazing ceased. Grassland butterflies in Ireland generally dislike large, unsheltered open areas even when these grasslands contain an abundance of nectar and larval foodplants. In such species-rich grasslands, it is among scrub that large butterfly populations will be found.
A butterfly gardener should take account of the value of maintaining a range of habitat types in an area, with native, mature, open woodland, dense scrub patches, scattered scrub and trees, open exposed ground and flower-rich grassy areas throughout. For a re-wilding project, native grazers, as well as domestic livestock, reintroduced Wild Boar and Beaver may be ideal to restore the landscape to something resembling its state before humans burned and felled woodland.
Winter is a time of meagre fare for butterfly and moth lovers. Sometimes we give up on our passion altogether for this season at least and yearn for warmth’s return, for Emperor moths, Orange-tips and Holly Blues to fly from March onwards.
Yet stirring in the darkness unbeknown to most exist a few select hardy winter moths. These occasionally come to outdoor lights. All three pictured here came to my outdoor light. On milder nights these seek out mates and breeding sites. There are some benefits to flying in winter. Bats, the scourge of nocturnal moths are safely out of the way, in deep sleep. There are far fewer insect predators to trouble moths. There are fewer insectivorous birds foraging in hedges and woods in daylight hours for resting moths.
These moths do not need to place their eggs on growing leaves. All breed on native trees, placing their eggs on or close to leaf buds or on the bark. The three moths, the December Moth, Winter Moth and Mottled Umber are flying now. The females of the latter two are flightless and simply wait on our beside the cocoon from which they emerged to be located by a male. Soon she lays her batch of eggs and expires, her job done.
Their eggs will hatch in April when the buds open. These will be a great feast for breeding birds who time egg-laying and hatching in synchrony with the availability of the soft, juicy, protein-rich larvae. Enough survives to pupate in June where they will await the onset of cold weather to hatch as adults.
Although winter is a vast empty space for many butterfly lovers especially after the excitement of Christmas has passed and we feel ready for spring only for weeks more winter to cast its colour-drained pall, winter moths offer just a little consolation. Sombre as December weather, they are a fitting complement to the shadowland that is winter.
December moth, male on a limestone wall, December 2019.This male Mottled Umber fluttered into the hall, initially attracted by the outdoor light.A male Winter moth found beneath the outdoor light above my front door. Many individuals are paler than this specimen. This moth is frequently attracted to windows when the light is on.
Winter Moths
Sharp winter light slants morning and afternoon
Dank vapour turns all cold blue
Short daylight and long night lonely under the moon
Little to see, less to do, fast time’s slow winter passage to rue.
But huddled close by the outdoor light
A furred, maned December moth
Braves a shivering winter night
Unmoved while light glows, a Sloth.
Fluttering before relaxing on his brightened masonry bed
A Mottled Umber, charcoal or brown on rust or cream
Blends on bark or stone, wings reflect an arrowhead
Vague and defined the impressionists’ dream.
Windows lit from inside casts the outside in darker night
Winter moth mirage, pale and plain,
A sylph of the dark yet a lover of glassy light
Like a wet birch leaf he clings to the pane.
His female patient on cocoon waits for mate and doom.
