Picking the top 10 must-see British butterflies is no easy task as the standard is remarkably high, even though only about 60 species grace our shores annually (including regular migrants). The truth is that our butterflies are remarkably emotive creatures, not least because they are essential elements of spring and summer sunshine.
The following is my selection of the top 10 must-see British butterflies, including tips on when, where and how to see them. All places mentioned below allow full public access.
Duke of Burgundy Hamearis lucina
No one knows how this tiny early spring butterfly obtained its name. Formerly common locally in woods, the duke is now a rare and rapidly declining butterfly, primarily of rough, ungrazed or lightly grazed limestone grassland, where it breeds on cowslip and primrose leaves in shady situations.
Most colonies hold only a handful of butterflies. However, the males gather in sheltered territories, or leks, which are occupied annually. There they squabble like mad and launch themselves against all-comers.
They are most active in the mornings, becoming quiescent after 2pm. The duke flies at cowslip time, late April through to late May, and nowadays is best seen in early to mid May.
Where to see: Top sites are Noar Hill near Selborne in Hampshire, Heyshott Down on the West Sussex Downs, the lower slopes of Ivinghoe Beacon in the north Chilterns and Rodborough Common near Stroud in the Cotswolds. His grace even has his very own blog.
Pearl-bordered fritillary Boloria euphrosyne
Another butterfly in rapid decline, having been widespread and locally common throughout southern and western mainland Britain.
It lives mainly in woodland clearings and on bracken hillsides, but also on rough limestone grassland around Morecambe Bay and along loch sides in the Western Highlands, breeding on violets among fallen leaves or dead bracken litter.
It flies mainly during May, but has early and late years, depending on the vagaries of spring weather. Cannily, it flies when the bugle, its favoured nectar source, is in flower. This is one of our most graceful butterflies in flight, skimming low over the ground vegetation, pausing only to visit flowers or bask, the males ceaselessly searching for females.
Where to see: The New Forest woods north-east of Brockenhurst (Pignal, New Copse and Parkhill inclosures), Bentley Wood in south-east Wiltshire, Cwm Soden near New Quay on the Ceredigion coast, Arnside Knott and Whitbarrow in south Cumbria, and Loch Arkaig in the Highlands.
Large blue Phengaris arion
The British race of this magnificent royal blue butterfly was declared extinct in 1979. Since then, the Swedish race has been naturalised in the West Country by a dedicated team led by top butterfly scientist Prof Jeremy Thomas.
This race is now quite well established in the Polden Hills in mid Somerset, where several colonies result from natural spread. It is also being re-established in the Cotswolds and Devon.
It flies during June on sunny slopes where the grass is kept short, and visits wild thyme flowers. The larvae feed for a while on wild thyme before becoming predators of the grubs of a single species of warmth-loving red ant. The large blue lives for 10 months underground in the ant nests.
Where to see: Access is difficult at most sites, and most colonies are extremely small. The National Trust runs an open access site at Collard Hill, near Street, Somerset. This supports one of the largest known colonies in Europe.
Swallowtail Papilio machaon
This tropical-looking butterfly is so large and colourful it can be spotted from 200m (650ft) away as it patrols over reedbeds. Today, it flies only in the major river valleys of the Norfolk Broads, where it breeds on milk parsley, a scarce wetland plant.
It is on the wing mainly from late May through to early July, though it is seldom numerous. In hot summers there is a partial, rather localised second brood during August. Swallowtails love the flowers of marsh thistle, bramble and flag iris, but hate wind. On windy days, they patrol sheltered areas in the lee of woodland.
Where to see: Pedestrian access is difficult on the Broads, but Hickling Broad National Nature Reserve (NNR) and How Hill nature reserve are good pay-for-entry sites, and the edges of Marsham Broad and the Butterfly Conservation reserve at Catfield Fen are also good. Mid to late June is usually the best time.
White admiral Limenitis camilla
Our most graceful butterfly in flight, the white admiral effortlessly skims the edges of trees and bushes along woodland rides in southern England, where it is common locally.
No insect loves woodland bramble flowers more, or graces them better. It is most numerous in late June and early July, but flies for only about a month. The larvae live in honeysuckle tangles situated in dappled shade. Occasionally specimens lack the distinctive white bands. The undersides of these ‘black admirals’ are especially beautiful – a once-or-twice in a lifetime experience.
Where to see: White admirals occur in many southern woods, but they are particularly numerous at Bookham Common near Leatherhead in Surrey, Pamber Forest south of Reading, and the southern parts of Alice Holt Forest in east Hampshire. These woods also support good populations of the large and spectacular silver-washed fritillary, the happiest of butterflies, which flies at the same time as the white admiral.
High brown fritillary Argynnis adippe
One of the loveliest of our butterflies, large, brilliant orange and most graceful, with pieces of silver on the hind wing undersides. But it is also our most rapidly declining butterfly, and is restricted now to a few bracken hillsides in the West Country, a tiny part of South Wales, and its stronghold – the lovely limestone hills around Morecambe Bay at the southern end of the Lake District.
It flies from mid June to late July (later in Morecambe Bay), and delights in basking on bracken fronds and visiting bramble, knapweed and thistle flowers. Its larvae feed on violets among leaf or bracken litter.
Purple emperor Apatura iris
No one forgets their first purple emperor, our most impressive butterfly. It is brave, bold and powerful, but is hard to see as it lives mainly in the woodland canopy, is active only intermittently, and occurs at low population density.
Moreover, it does not visit flowers, though males periodically descend to woodland rides to imbibe moisture, often from unsavoury substances. In normal summers it is most numerous during the first two weeks of July – look for emperors when the white admirals and silver-washed fritillaries are well out.
Although associated with oaks in southern forests, it is actually a butterfly of sallow jungles in well-wooded landscapes, with the males gathering on groves of trees on sheltered hill tops, out of the wind.
Where to see: Bentley Wood, Wiltshire and Bookham Commons, Surrey, Botany Bay, Chiddingfold Forest, on the Sussex/Surrey border, and best of all, Fermyn Woods, near Corby in Northants.
Mountain ringlet Erebia epiphron
This is our only mountain butterfly, necessitating a midsummer trip to the high fells of the central Lake District or the mountains of the south-west Highlands. Most colonies are found above the 500m (1,640ft) contour line.
There, mountain ringlets blow about in the wind, crashing moth-like into tussocks, and feed avidly on tormentil and, where available, wild thyme flowers. But it is well worth the trip, for no other British butterfly is quite like the mountain ringlet, and the iridescence of freshly emerged specimens is exquisite.
The flight season is very variable, seemingly consisting of pulses of emergence from early June through to late July, with early and late flying colonies.
Where to see: Ben Lawers NNR, Perthshire, is the classic locality in Scotland. In the Lake District, the slopes of Fleetwith Pike above Honister Youth Hostel are renowned, also Wrynose Breast and Cold Pike.
Adonis blue Polyommatus bellargus
The electric iridescent blue of the male’s wings is almost tropical, making this one of our most special butterflies.
It is a local butterfly of south-facing chalk and limestone hillsides in southern England, though in favoured places it is often abundant, and it has recently expanded its range due to conservation efforts.
There are two broods, in early summer and again in late summer. The second brood is usually much stronger, and often coincides with the tail end of the chalkhill blue season, its sky blue cousin. These butterflies both breed on the same plant, horseshoe vetch, in short turf.
Where to see: The south-facing slopes of the Isle of Wight chalk ridge and the Purbeck Hills of Dorset, Denbies Hillside near Dorking on the North Downs, many of the Wiltshire downs, and Rodborough Common in the Cotswolds.
Adonis blue Polyommatus bellargus
Brown hairstreak Thecla betulaeThe latest of our butterflies to emerge, the brown hairstreak flies from late July into September. This is one of our hardest butterflies to see, as observing it requires much standing around, waiting, searching ash trees with binoculars and neck ache.
But this butterfly has a cult following and its own website. It occurs at low population density in landscapes rich in blackthorn, the larval foodplant, but is indolent and flies mostly in early mornings.
The males then laze around, high up on ash trees close to blackthorn hedges or tangles, where they feed from sticky ash buds. Sometimes males and females visit angelica, bramble and hemp agrimony flowers. Females flit about in early afternoon, laying eggs on blackthorn shoots and basking in late summer sunshine.
Where to see: Alners Gorse in north Dorset, Noar Hill in east Hampshire, Shipton Bellinger Roughs in west Hampshire, the Steyning Rifle Range in West Sussex, and Bernwood Meadows in Oxfordshire.
Matthew Oates is a butterfly expert and media naturalist for the National Trust. A passionate all-round wildlife enthusiast, he is the author of books such as Butterflies and All About Butterflies. Illustrations © Richard Lewington
Main image: Adonis blue/Getty
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