The usual way to present butterflies is by family, beginning with the primitive, moth-like skippers and ending with the ‘browns’. Instead, and in keeping with the human-centred focus of this book, I prefer to begin with the commonest and most familiar species and finish with the rarest. These thumbnail sketches are not intended to be comprehensive. But within the small frame of each butterfly’s personality I have included a few details of season, larval food plant and distribution.
Commonly known as the cabbage white, this is the butterfly that is most linked with human habitation. Gardeners and allotment holders will know all too well their clutches of yellow, bottle-shaped eggs and swarms of hungry, hairy, yellow-and-black caterpillars, busy perforating and shredding the leaves of brassicas and nasturtiums. The caterpillars imbibe mustard oils from their food plant which makes them distasteful to birds and mice. But this defence is of little use against parasites and many cabbage white caterpillars end up as a living dinner for parasitic flies and wasps. The Large White is a wanderer, easily capable of crossing the Channel, and can be found almost anywhere. Setting understandable antipathy aside, it is an attractive butterfly, its great white wings bordered and dotted with black and grey scales, and, beneath, pale yellow delicately speckled with black.
This smaller relative of the Large White also feeds mainly on brassicas but its plain green caterpillar is more solitary, better camouflaged and hence not so familiar. It too is a very common butterfly and large numbers may build up by the end of summer. In the Great Butterfly Count of 2013 the Large and Small Whites were the most numerous of all our butterflies. Apart from the size difference, Small Whites are distinguished by smudgy dots on their forewings with less black on the wingtips. The smaller spring generation is a pure white; the summer one is overcast with black scales.
The lovely orange, yellow and black Small Tortoiseshell is not only our most colourful garden butterfly but also often the commonest. Among its favourite flowers are buddleia, ice-plant and Michaelmas daisy. The butterfly also enters houses looking for some dark, quiet place to aestivate (a kind of summer-sleep) or, later on, to hibernate. Emerging in the first warm days of spring, generally looking faded and tattered, the Small Tortoiseshell is one of the longest-lived butterflies. It is also one of four whose caterpillars feed on stinging nettles in sunny places.
The Peacock, formerly known as the Peacock’s Tail, has a unique set of iridescent ‘eyes’ set in each wing. Like the Small Tortoiseshell it is a frequent garden visitor, especially to buddleia flowers. Its spiky black caterpillars feed on nettles and are easy to spot when full grown. The Peacock is another long-lived butterfly, emerging in late July, hibernating in cool, dark places over winter and emerging again in the spring. It is one of the few butterflies that can make an audible noise – a faint rustle as it shakes its wings.
The Red Admiral is one of the world’s best-known butterflies. It is not a British resident but a long-distance migrant. Each year its splendid red-slashed wings power the butterfly from the Mediterranean to northern Europe where it lays its eggs on nettles to produce a fresh, British-born generation. In recent years a few Red Admirals have survived the winter by hibernating. Hence the butterfly can be found at almost any time of year – even on mild, sunny days in January. It is commonest in late summer when the butterfly is attracted to rotting fruit in gardens and orchards as well as buddleia and Michaelmas daisies. Like all migrant butterflies the Red Admiral is commoner in some years than others.
The Comma is easily recognised by the ragged outline of its wings and the tiny white ‘comma’ or c-mark on its dark underside. No butterfly looks more like a withered leaf when at rest. The Comma is a butterfly success story; it is actually commoner and more widespread today than it was in Victorian times. There are two broods, a bright orange form in midsummer and a darker brood later in the year which overwinters. Like the previous three butterflies, the Comma lays its eggs on nettles, though the caterpillar also feeds on hop and elm. Unlike them, the Comma is seldom seen in large numbers but a patch of overripe blackberries in a sunny position is sure to attract a few.
This bright yellow butterfly is a familiar harbinger of spring as it flies along the wayside looking for a mate. Only the more active males are sulphur-yellow; the slightly larger female is paler and in flight can be mistaken for a Large White. The Brimstone is a frequent visitor to gardens where it is drawn to pink or purple flowers. It lays only on buckthorn or its relative, alder buckthorn. The butterfly emerges from its chrysalis in late July and remains on the wing for a month or so before hibernating among ivy. It wakes up in early spring, usually still in good condition, and only then does it mate and lay its eggs.
Another familiar springtime butterfly, the Orange-tip is a restless inhabitant of waysides and damp grassland. Only the male has the bright orange wingtips; the more elusive female resembles a Small White but has green scales on its undersides – colouring that makes a very effective camouflage when the butterfly is feeding or at rest. Its orange, bottle-shaped eggs are laid on hedgerow garlic mustard or lady’s smock, both of which have long seed pods on which the slim green caterpillars feed.
The Green-veined White is a much-maligned butterfly. Though related to the Large and Small Whites it rarely shows any interest in crop plants, despite its species name of napi – from napus, the turnip or swede. Like them, it is a common garden visitor but lays its eggs on wild cresses such as lady’s smock and watercress in damp places and woodland rides. It is so named from the heavily marked veins on the undersides of its wings; the appearance of green is actually an optical illusion achieved by black scales on a yellow background. The Green-veined White rears a succession of broods through the year. One of its secrets is a successful mating plan – the female is promiscuous and the male generous, passing on a packet of protein with its sperm as well as a sprinkling of lemon-scented ‘love-dust’. It is among the most widespread of our butterflies.
Most of our dozen species of blue butterflies inhabit wild downs and flowery banks. Only one is common in gardens and that is the Holly Blue, a pretty powder-blue butterfly with white undersides. It is double-brooded, flying in the spring and again in late summer, often along ivy-covered walls and hedges at about head height. Its plump, sluggish caterpillars feed not on leaves but on green holly berries in the spring and ivy buds in the summer. Unlike other garden butterflies, the Holly Blue rarely visits flowers; it prefers instead to sup on the sticky ‘honeydew’ left on leaves by feeding aphids.
This is the most widespread of the browns, a sub-family of mostly sombre-coloured butterflies whose caterpillars feed on wild grasses. The Meadow Brown is the quintessential brown butterfly of midsummer meadows with mud-coloured wings enlivened by an eye-spot in the corner of the forewings. Time was when you could expect to find Meadow Browns in almost any patch of tall grass. Today, like so many butterflies, it has been pushed to the margins by intensive agriculture but you still find the butterfly across Britain on rough banks and downs, in disused quarries and field headlands. The Meadow Brown has been studied intensively since its wing pattern is variable and influenced by genes. Unlike most butterflies, it can fly in dull weather; perhaps brown wings help to keep a butterfly warm.
Smaller and more brightly coloured than the Meadow Brown, the Gatekeeper likes flying along thick, brambly hedges that border grass fields. Ragwort and ox-eye daisy are among its favourite flowers. It visits gardens and, being one of the last species to emerge, is the signature butterfly of late summer. It remains on the wing through August, still fresh when most other browns are becoming thin and worn.
This is our duskiest butterfly, dark chocolate-brown above but with a surprise underneath: a curved line of beautiful little rings inset with white dots. It is a quiet butterfly more tolerant of damp and shade than most species. It can even fly in light rain. Feeding on coarse, tussocky grass such as cock’s-foot and false brome, the Ringlet has adapted well to changes in the landscape such as newly planted trees or shrub-invaded grassland. It is widespread in England and is more local but increasing in lowland Scotland. Its signature ring markings vary from large and almond-shaped ‘eyes’ to tiny ring-less dots.
Smallest of the browns, this penny-sized butterfly is easily recognised by its pale golden-brown colour. Formerly among our commonest and most widespread species on wild grassland and heath, it has decreased in many places. The caterpillar feeds on fine grasses which tend to get crowded out when regular grazing ceases or when scrub closes in. The Small Heath flies low and you often see it bobbing just above the ground or settling on the path. It has an unusually long flight season running all the way from May to September.
This is our woodland brown. With its pattern of light brown or yellow over dark brown the Speckled Wood is well camouflaged in the dappled light filtering through the canopy. An aggressive insect, it will defend its corner of leafy glade against all comers. Like several other browns it has increased its range and is now found in suitable places over most of lowland Britain, even visiting gardens. When not pursuing intruders, the Speckled Wood is often seen basking on a leaf or feeding on the flowers of the woodland edge, especially brambles. It has a long flight season with a succession of broods, from May to September or even later.
Long grass is the home of this, the commonest of the skippers. Golden-brown in colour, with a dark dash-shaped ‘sex-brand’ on the forewing of the male, it lives up to its name with a darting, hovering, skipping flight; the Small Skipper can even fly sideways. Like several other ‘golden skippers’, it basks in a distinctive way with the lower wings held flat and the upper pair at an angle. Like most of our eight skippers, the Small Skipper lays its eggs on grass, usually Yorkshire fog. It is found in July over most of lowland England and Wales and is slowly edging northwards.
Most butterflies are easy to identify on the wing, but the Essex Skipper, being very similar to the Small Skipper, demands a close look. The only sure way to tell them apart is from the coloured tips of their antennae: with the Essex Skipper they are black, as though dipped in ink, while those of the Small Skipper are pale brown. The Essex Skipper was first discovered in that county but is now widespread in rough grassland across most of lowland England.
The Large Skipper is not, in fact, much bigger than the Small Skipper but looks quite different in its attractive mottled pattern of light and dark brown. Fresh ones can look almost golden in flight. Male Large Skippers are a delight to watch as they guard their territory, such as a patch of tall grass or a sunny hedge-bank, from their chosen perch on a leaf or grass head, darting out in a circular flight and then back again. It is a butterfly of open woodland and scrubby banks, flying in June and early July. Unlike most skippers, it visits gardens.
Though, as its name implies, this is the commonest of the blues, the Common Blue is no longer generally common. Its stumpy caterpillar feeds on bird’s-foot trefoil and that tends to define the places where you find the butterfly: sunny downs, banks, coastal cliffs and dunes, wet meadows and railway cuttings. Only the male is a clear shiny blue (often with a touch of lavender); the duller female is brown with variable orange spots and streaks of darker blue. In the south the butterfly has a long flight season, from mid-May to the end of summer.
This fiery little butterfly likes dry, flowery places, such as downs and heaths. You rarely see more than half a dozen together except sometimes in gardens in late summer. The Small Copper lays its eggs on sorrel but the adult has a fondness for flat, daisy-like flowers such as ragwort and fleabane. One fairly common form has iridescent blue spots on the hindwing: butterfly jewellery. It is found over most of lowland Britain and, being double-brooded, has a long flight season lasting from May through to September with a short gap in between.
Like its relative the Red Admiral, the Painted Lady is a famous long-distance migrant, found all over the world. Generally it is much less common than the Red Admiral but about once a decade the butterfly has a truly glorious season, as it did in 1996 and 2009. Painted Ladies often share the same buddleia blossom with Peacocks and Small Tortoiseshells, their powerful fawn, black-tipped wings held stiffly to catch the sun. Its spiky caterpillar feeds on thistles. Most of the butterflies that visit Britain in early summer emerged from the chrysalis far away in the desert edges of Morocco. As befits such an epic traveller, the Painted Lady flies fast and straight but once settled on a thistle head or a buddleia it becomes completely absorbed and can be approached closely.
Our next group are butterflies that are less likely to visit gardens and more characteristic of wilder places, whether grassland, woodland or some other natural habitat. As a boy I thought of them as ‘holiday butterflies’ because that is when I used to see them, on country walks and bike rides, or by the seaside.
This is the third and last of our regular migrants, a sunny yellow butterfly with a fast, powerful flight. In most years, Clouded Yellows are commonest along the south coast or the southerly downs of England. In good years – 1983 and 2000 were particularly good – they fly far inland and can turn up almost anywhere. In flight they look like pelting golden guineas. It is hard to get a good view of the dark-bordered wings, though, because the Clouded Yellow always rests with its wings tight shut. A proportion of the females are creamy white or pale grey. They visit us from July onwards for as long as warm weather lasts. The butterfly lays on vetches; in the past, fields of clover and lucerne grown for fodder were famous for attracting them. Recently, adult butterflies have hibernated successfully in sheltered places along the south coast to emerge in early spring.
I always feel sorry for the Dingy Skipper which is routinely described as our dullest butterfly. It is in fact rather pretty when fresh, with its textured greyish wings and intricate pattern of dark and white spots. Unfortunately these soon fade and the wings turn a dirty grey-brown with age. The Dingy Skipper flies in the late spring. You may see it rising up at your feet and darting away, only to settle on the path a little further along. It likes warm, sheltered places with plenty of its food plant, bird’s-foot trefoil.
The Chalkhill Blue is named after its habitat: the chalk and soft limestone downs of southern and eastern England. Its silvery blue wings, the colour of an English sky, have dark edges and chequered margins with a sprinkling of eye-spots underneath. The squat green caterpillar feeds only on horseshoe vetch, but the butterfly enjoys feeding on a wide variety of flowers in late summer including ground thistles, knapweed and scabious. Collectors used to love the Chalkhill Blue for its unusual variety of genetic forms, all of which they assiduously catalogued, like rare antiques.
Rarer than the Chalkhill Blue, the Adonis Blue is nonetheless often common where found. It is the brightest of blues, a dazzling pure blue like a living sapphire. The Adonis shares the same habitat and food plant as its relative the Chalkhill Blue but avoids competition by laying at different times. While the Chalkhill has a single annual brood, the Adonis is double-brooded, appearing in May and again in August. It prefers southern, sun-baked hillsides where the turf is kept well cropped by rabbits or sheep and cattle.
This is the smallest British butterfly, no bigger than a thumbnail, and, being dark as well as small, easily missed. The Small Blue is also the most parochial of butterflies, seldom straying far from its birthplace in a patch of kidney vetch on a warm, sheltered bank. Widespread in late May and June in the south, the Small Blue is much more local further north and one of Scotland’s rarest butterflies. In Europe you often come across dozens of them feeding on seepages by a path, probing the mud with their little tongues. But in Britain they seem to prefer fresh rabbit droppings!
This is a blue that is, in fact, brown, though when freshly emerged it has an iridescence that appears silvery or blueish in flight. The Brown Argus is widespread in the southern half of Britain in rough, flowery grassland. It was once regarded as another downland butterfly, but it has also colonised quarries and other waste places by widening its choice of caterpillar food plants from rock rose to include storksbills and cranesbills. North of the Midlands the Brown Argus is replaced by its close relative, the Northern Brown Argus.
This northern butterfly was only clearly distinguished from the Brown Argus in the twentieth century. Most have a white dot in their forewings but they are otherwise very similar to their southern cousin and also have similar habits, including the same larval food plant, rock rose. The Northern Brown Argus flies in June and July on sheltered hillsides in northern England and eastern Scotland. Those in Durham, where the white spot is faint or absent, were known as the ‘Castle Eden Argus’.
Despite its name, the Marbled White is not a true white but a brown. Like other browns its caterpillar feeds on grasses and the butterfly flies in open, grassy places in July, especially chalk and limestone hillsides. Its bright pattern, chequered like a chessboard, is unmistakable. Being toxic, this butterfly can afford to draw more attention to itself than other, more edible, browns. This is another butterfly that is gradually extending its range northwards. The Marbled White has a lazy, looping flight and often perches on a favourite flower, such as scabious or knapweed, with its wings open. Few species are quite so easy to approach and photograph.
This is our only butterfly with truly green wings though that colour is confined to the undersides. Unobtrusive and easily overlooked, it is found in small numbers in an exceptionally wide range of habitats from chalk downs to open woods and heaths. The reason for this is the wide range of food plants available for its attractive green-and-yellow caterpillar: gorse on commons and heaths, trefoils on the downs, bilberry on moors, bramble in woods. The Green Hairstreak is a delight to watch in late spring, flashing green and brown in a hopping, jinking flight or resting with wings tight closed with its green underwear on show. Should your hand be sweaty it will readily sit there probing your skin with its little tongue.
Our other four species of hairstreak are woodland or wood-edge butterflies which spend most of their adult lives high up in the woodland canopy. The Purple Hairstreak lays on the twigs of oak and is found in suitable woods throughout Britain except in northern Scotland. The small, dark, purple-shot butterfly has a jinking flight that is most easily followed with binoculars. Like other hairstreaks it is often more easily detected by looking for the small white eggs or the brown caterpillar than the adult butterfly.
The elusive White-letter Hairstreak is so called from the wobbly ‘w’ mark on the underside of its hindwing. The caterpillar feeds only on elm or wych elm in woods and hedgerows. Fortunately, despite elm disease, the butterfly is holding on reasonably well in England, especially in the Midlands. The butterfly can be watched with binoculars as it jinks or walks around a flowering elm tree. If you are lucky you might see one or two nearer the ground, sipping nectar from bramble blossom.
The Brown Hairstreak is even more elusive than the White-letter, another butterfly of the treetops – usually oak or ash – which occasionally descends to feed on flowers on hot days in August. The attractive female, which has golden-brown patches on its dusky wings, lays on blackthorn hedges. One reason for its rarity may be that such hedges are routinely flailed, resulting in the loss of most of the overwintering eggs.
We have nine species of bright orange-brown butterflies speckled with black and known as fritillaries. The second-largest and overall the commonest is the Dark Green Fritillary, named after the beautiful green hindwings inset with silver ‘pearls’ (though the shade of green is not ‘dark’ but spring-fresh). The elegant, fast-flying butterfly is found in July on flower-rich grasslands across much of Britain though it is most frequent on the downs and along the coast. Like several of our fritillaries, it lays on violets – chiefly the hairy violet – but the adult butterfly prefers thistle heads.
The largest of the fritillaries is a noble butterfly with rich golden-brown wings and, beneath, pale green washed with trickles of silver. Its undulating flight, now fluttering, now gliding, is a delight to watch, especially in courtship when the male drops showers of scent and performs aerobatics which are all the more impressive against the deep green shadow of woods in midsummer. The butterfly lays on the bark of trees but the young caterpillars descend to feed on violets on the woodland floor. The Silver-washed Fritillary is more tolerant of shade than other fritillaries and that may have been its saving grace. It is still found, in July, in most of the larger woods in south-west England and more locally elsewhere. Those with long memories may recall its superabundance in that hot year, 1976. It could happen again.
Sometimes sharing the same bramble patch as the Silver-washed Fritillary is this equally elegant butterfly. Its gliding flight, skimming the contours of the trees, seems effortless. The butterfly is equally striking when at rest, its austere white stripes on a dark-brown background contrasting with the paler browns and blue-greens of its undersides. Though usually seen only in ones and twos, in late June and July, the White Admiral is fairly widespread in woods across southern and eastern England. Its spiky green caterpillar feeds on honeysuckle in the half-light of deep woods.
The largest of the browns, the Grayling is a butterfly of warm, dry places, especially heathlands and sheltered parts of the coast. A late summer butterfly, you often spot it as it rises in front of you, soon settling down again further along the path. Its greyish hindwings form an effective camouflage on sandy paths and rocks, and the butterfly can angle its wings so that there is no shadow. It seldom visits flowers, apart from Bell Heather, but will drink from a salty puddle or even the sticky resin on a fence-post. The pale brown caterpillar feeds on bent-grasses and, unusually for butterflies, makes an underground chamber for its chrysalis.
The Wall was once a common butterfly across most of England and Wales on sunny hillsides, banks and even gardens. But it has experienced a steep and still mysterious decline and is now frequent only by the coast, on steep chalk hills and on spoil heaps in the industrial north where there is plenty of the fine-leafed fescue on which its slim green caterpillar feeds. The butterfly likes to bask on bare ground in full sun, often on footpaths. Close up it is unmistakable – and the pattern does resemble a brick wall – but in flight the Wall can be mistaken for a Comma or even a fritillary.
The kind of dry heaths loved by the Grayling are also the home of this pretty blue, so named from the pinheads of iridescent scales on the undersides of its hindwings. Although it can be very common where found, the Silver-studded Blue is more or less restricted to heathlands and coastal headlands in the southern half of Britain where it flies in July and early August. The caterpillar feeds on gorse and other heathland plants and is looked after by ants who take the chrysalis down into their underground nest for safekeeping.
The smallest of the skippers and our second-smallest butterfly, the Grizzled Skipper is a chequered, moth-like butterfly whose wings become a grey blur in flight. It is a feisty little insect which engages in aerial dog-fights with rival males over its chosen patch of crumbling soil or bank. Though much declined, the Grizzled Skipper occurs locally across England and South Wales especially in partially wooded quarries and crumbling banks where its larval food plant, wild strawberry, grows.
Purple Emperor watching has become a popular pursuit. Many make the journey, in early July, to one of of its known localities in the East Midlands and south where you have a reasonable chance of seeing one. This is a glamourous butterfly, large, dark and strong, with a white band flickering down the wings. Only the male displays a purple iridescence; the slightly larger and more elusive female is plain dark brown and white. The butterfly spends most of its life in the treetops but it sometimes descends to feed in puddles or to bait, such as rotting banana skins – or to lay on sallow bushes. The Emperor is also attracted to fresh droppings, putrefying rabbits or even shiny car roofs – but not flowers. Its horned caterpillar feeds on sallows in the shade of oaks. Like your first sight of a whale or an eagle, you never forget a Purple Emperor.
You never forget your first Swallowtail either, skimming majestically over the Norfolk reeds in May and June with lazy beats of its tiger-striped, elegantly tailed wings. This is our largest resident butterfly, an endemic race named britannicus which has darker markings than usual. Our Swallowtail is an extreme specialist, tied to the Norfolk Broads and the nearby coast by the rarity of its food plant, milk parsley, even though, in captivity, its gaily striped caterpillar will happily accept carrot tops. The butterfly often flies over water but favours open reed beds and wet, flowery meadows. The paler continental form of the Swallowtail is visiting us in increasing numbers and may soon become a settler on the south coast.
This beautiful springtime fritillary, named from the row of silver spots under the hindwings, was once common in open woods throughout most of Britain. Unfortunately it has suffered a catastrophic decline and is now largely restricted to the western half of England and parts of Wales and Scotland. The reasons may be complex but the increased shading of so many woods and the decline of its caterpillar’s food plant, violets, are probably the main triggers. Many of its remaining sites are nature reserves.
The Small Pearl-bordered flies a few weeks later than its close relative, the Pearl-bordered, and so is usually still fresh while the latter is fading. But you need a good look at the arrangement of ‘pearls’ and spots on the undersides to be sure. The Small Pearl-bordered relies less on woodland than its relative, flying in damp grassland and heath wherever its larval food plant, marsh violet, occurs. Today it has become a western species in England but is more widespread in Scotland.
This too was once a fairly common butterfly in woodland glades over lowland England and Wales. But today the High Brown Fritillary is rare and confined to six areas in western England and South Wales where it inhabits sheltered, open places in the vicinity of woods. The interiors of our shady woods are now too cool to support this warmth-loving butterfly and its equally warmth-loving, basking caterpillar. The latter feeds on violets among dry fronds of bracken but the fast-flying butterfly visits flowers, especially brambles.
This is yet another fritillary in decline and one now found mainly in the western half of Britain (it is more widespread in Ireland). The Marsh Fritillary has two contrasting habitats: wet pasture and the dry chalk downs of Wiltshire and Dorset (where its name is inappropriate). Prettily marked in orange, yellow and black, this butterfly’s numbers fluctuate from one year to the next depending on the activity of its parasites. It flies in June. Most colonies are small and the Marsh Fritillary is increasingly reliant on conservation management for its survival.
Today this beautiful butterfly has only a toehold in Britain. It is confined to sunny coastal slopes on the Isle of Wight, especially where the clay cliffs have slumped towards the sea. This is a gem of a butterfly with a carnival of golden-yellow spots and bands on its underside, made lovelier still by its maritime setting. Its black, spiky caterpillars live in a communal nest on plantains and so are quite easy to find. The Glanville Fritillary has a relatively short flight period from mid-May to early June.
The Heath Fritillary has long been rare and confined to a few open woods and sheltered valleys in Kent and the West Country. The butterfly thrives best in woods managed by regular cutting to maintain clearings full of flowers, including cow wheat and plantain on which the caterpillars feed. At one time its survival seemed uncertain but, fortunately, the Heath Fritillary has responded well to conservation management and in a few woods it can be the commonest butterfly during its flight time in late May and June, sometimes appearing in hundreds.
The Black Hairstreak is the rarest of our five hairstreaks, being confined to woodland in the East Midlands between Oxford and Peterborough. Like its distant relative, the Brown Hairstreak, it lays its eggs on blackthorn bushes in and around woods. The butterfly flies in June and, if you are lucky, you may find it in numbers feeding on bramble or privet blossom.
The Scotch Argus is not related to the Northern Brown Argus but it is confined to Scotland, apart from two colonies in the Lake District. It is an attractive deep-brown butterfly with orange bands and chequered wing margins, which frequents damp grasslands and scrub in late July and August. The males flutter tirelessly above the grass tussocks while the much more retiring females choose clumps of purple moor-grass to lay their tiny, speckled eggs.
This small brown butterfly is our only true mountain species, occurring locally on slopes and hilltops in the Lake District and the western Grampians. It flies in June and early July, depending on the season, and only in sunshine. Its caterpillar feeds on mat-grass and, if the summer is short, it may take two years to develop. The Mountain Ringlet is one of our most elusive butterflies. It is also the one most at risk from climate change.
The warm brown Large Heath is one of our few wetland butterflies, occurring in peat bogs from North Wales and the Midlands northwards. It is also among the most variable of butterflies with three distinct forms that were once regarded as different races or even species. Though rather elusive, it can be quite common should you happen to find yourself in the right kind of bog on a rare sunny, windless day in June or July. The butterflies are attracted to the flowers of cross-leaved heath but the striped green caterpillar feeds on cotton-grass.
The Wood White is a dainty butterfly with the slowest, floppiest flight of any species. It flies in May with a smaller later brood and occurs mainly in large woods or wooded cliffs in the southern half of Britain. No more than fifty colonies are known and some of those are small. The caterpillar feeds on a variety of vetches and trefoils. In Ireland a closely related species, the Cryptic Wood White, Leptidea juvernica, is more widespread and not confined to woodland.
This small brown, chequered butterfly is the only member of its family, the metalmarks, in Europe. Like so many woodland butterflies it has suffered a severe decline and now occurs mainly in sheltered, scrubby limestone grassland and in open woodland in south and west England. Its nocturnal caterpillar used to feed mainly on primrose in coppiced woods but today you are more likely to find it on cowslips in the open. The Duke flies in May, and if you manage to spot as many as half a dozen you are doing well.
This stout-bodied butterfly flies close to the ground on hot August days with a fawn blur of wings. Though very local and confined to southern England it is sometimes found in good numbers on the slopes of chalk downs in full sun, especially where lumps of chalk and bare earth appear among short tussocks of fine grass. It has the ugliest of caterpillars, described by Jeremy Thomas as ‘a brown-green wrinkled maggot’.
As its name implies, this is a Dorset butterfly and one more or less confined to the coast. Here it thrives in sheltered valleys where there is plenty of its larval food plant, tor-grass. The butterfly is darker than the Small Skipper, with which it often flies, and the female has an attractive circle of golden spots on its forewings.
Extinct in England, the Chequered Skipper is still found in a limited part of Scotland, in Argyll, where it flies in small numbers in open woodland and sheltered wet hillsides in late spring. It is the prettiest of the skippers, with light brown spots over a dark brown background, and has a liking for blue flowers such as bugle and bluebell. The caterpillar feeds only on purple moor-grass.
The native Large Blue died out in 1980 but a similar-looking race from Sweden has been introduced with some success. There are now around twenty-five sites where small colonies of this inky-blue butterfly have been established, all of them in southwest England. The Large Blue is wholly reliant on a species of ant that carries its caterpillar into its nest to spend the rest of its development underground. Hence, to survive, the butterfly needs not only its food plant, wild thyme, but plenty of its host ants nearby.
Although the Large Tortoiseshell was last seen in any numbers more than sixty years ago, it is possible there are small breeding colonies on the Isle of Wight and perhaps elsewhere. The butterfly, whose caterpillar feeds on elm, was always elusive even though it sometimes visited gardens. It is also possible that it may one day recolonise through natural means.
Three former British butterflies are now extinct. These are the Large Copper, Lycaena dispar; Mazarine Blue, Cyaniris semi-argus; and Black-veined White, Aporia crataegi. A Dutch race of the Large Copper was successfully introduced to the Fens for a while but the colony has since died out. Undoubtedly more attempts will be made in future, most likely in the Norfolk Broads.
Eight rare migrants are traditionally counted as British. These are: Queen of Spain Fritillary, Issoria lathonia; Camberwell Beauty, Nymphalis antiopa; Long-tailed Blue, Lampides boeticus; Short-tailed or Bloxworth Blue, Cupido (or Everes) argiades, Bath White, Pontia daplidice; Pale Clouded Yellow, Colias hyale; Berger’s Clouded Yellow, Colias alfacariensis; and the Monarch, Danaus plexippus. After its surprise showing in summer 2014 we may have to add one more species, Yellow-legged Tortoiseshell, Nymphalis xanthomelas. Some of these scarce migrants have occasionally laid eggs here and even produced home-bred butterflies. Thanks to butterfly hotlines, the chances of lucky sightings have greatly improved.