8 rare butterflies in UK woods and why they need our help

Delicate, beautiful and tantalisingly elusive, these rare butterflies bring a splash of extra colour and excitement to the UK’s woodlands.

The UK's woodland butterflies have declined by 54% since 1990. Learn more about eight of the rarest, why they’re in trouble and where you can still spot them.

1. High brown fritillary (Fabriciana adippe)

Britain’s most threatened butterfly was once spread right across England and Wales, but now, the high brown fritillary has lost 85% of its population since the 1970s. It depends on bracken and common dog-violet to breed – laying eggs on the former and feeding on the latter as a caterpillar.

This large butterfly has a strong, powerful flight and eye-catching orange forewings covered in black markings. The underside of its hindwings have a scattering of silver-white markings, and a row of silver-centred, red-brown spots towards the outer edge. It’s on the wing from June until August.

Where to see a high brown fritillary

The high brown fritillary is found at just 50 sites, but conservationists are working hard to save it from extinction. It has strongholds in Dartmoor, Exmoor, South Cumbria’s low fells and the limestone areas of Morcambe Bay. There is also a single colony clinging on in Wales.

2. Heath fritillary (Melitaea athalia)

The heath fritillary is a butterfly of coppiced woodland. In fact, it was once known as the ‘woodman’s follower’ as it follows the cycle of cutting. Its colour and wing patterns can be quite variable, but generally it has a dusky, orange-brown chequered pattern. It can be seen flying close to the ground with characteristic flits and glides between May and August.

Where to see a heath fritillary

Like many rare UK butterflies, habitat loss almost drove the heath fritillary to extinction. It’s now restricted to coppiced woodlands in the southeast, where the caterpillars feed on common cow-wheat, and sheltered heathlands in the southwest, where they feed on ribwort plantain and germander speedwell. Excitingly, this butterfly has now made our very own Victory Wood in Kent its home after years of restoration work.

3. Black hairstreak (Satyrium pruni)

Beautiful and elusive, the black hairstreak spends nearly all its time in the tree canopy feeding on honeydew secreted by aphids. Its upperwings are chocolate-brown with red edges. Its underwings have a row of black spots bordering a red edge, plus a white, wavy streak forming a shallow ‘W’ shape. This often means it gets confused with the white-letter hairstreak, which lacks the row of black spots on its hindwings and has a much more defined ‘W’ marking.

Where to see a black hairstreak

This rare butterfly declined steadily during the 20th century and is now found at just 50 sites in the UK – in thickets of blackthorn in woods between Oxford and Peterborough. It tends to stick to one area rather than colonise new ones and breeds almost exclusively on blackthorn, making it incredibly sensitive to habitat loss. It’s on the wing during June and July.

4. Wood white (Leptidea sinapis)

This dainty woodland butterfly has a distinctive slow, fluttering flight and is best seen on still, sunny days in sheltered woodland rides and glades, where it feeds from knapweed, bird’s-foot-trefoil and bugle. The caterpillars are partial to vetches as well as trefoils.

To identify the wood white, look out for bright white forewings with rounded edges and, in males, a black mark on the wing edge. Both male and female wood whites have mottled grey markings on the underside of their wings. You’ll usually catch them out and about from May to June or July – there may even be a second brood in August.

Where to see a wood white

Sadly, the reduction in woodland management practices such as coppicing have seen a steep decline in this delicate butterfly. The wood white is now very rare – confined to central and southern England with just a single surviving colony in the southeast. It needs woodland rides to thrive but can also be found in scrubby habitat or tall grassland in places like disused railways and quarries.

5. Purple emperor (Apatura iris)

On the wing from late June to early August and one of the most recognisable rare butterflies in the UK, the purple emperor is large and most definitely in charge. Its iridescent purple wingspan ranges from 75–84mm, and male purple emperors will chase away anything that strays into their territory. It also has morbid dining habits – mostly feeding on aphid honeydew and tree sap high in the canopy, but also descending to the ground to probe for salts in animal dung or carrion.

Where to see a purple emperor

The purple emperor butterfly can now only be found in large expanses of deciduous woodland in southern England, including between Wiltshire and Hampsire, Surrey and West Sussex, and Oxfordshire and Hertfordshire. Males seem to prefer showing off around tall oak trees, while the caterpillars depend on sallows such as goat willow for their diet. It’s thought that peoples’ inclination to remove sallow scrub has sadly contributed to the purple emperor's shrinking range.

6. Duke of Burgundy (Hamearis lucina)

This small butterfly can be found in sunny clearings in ancient woods, as well as scrubby chalk and limestone grassland, between May and June, where it lays eggs beneath the leaves of primrose and cowslip plants. It looks like a tiny fritillary – orange and brown on top, with rows of white spots on the underside of its hindwings.

Where to see a Duke of Burgundy

Sadly, Duke of Burgundy numbers have crashed by 89% since the 1980s and this rare butterfly is now found in just a few parts of England. It has a stronghold in southern areas from Kent to Gloucestershire, plus a few isolated colonies in the Lake District and North York Moors.

7. Pearl-bordered fritillary (Boloria euphrosyne)

One of the earliest fritillaries to emerge, the pearl-bordered fritillary can be spotted from as early as April in woodland clearings or on rough hillsides with lots of bracken. Its black-patterned, bright orange upperwings are sure to catch your eye as it flies low to the ground, but its underwings are the real masterpiece. They have a red, yellow and orange stained-glass pattern, with a row of seven silver ‘pearls’ around the outer edge. These are bordered by red chevrons, while the similar-looking small pearl-bordered fritillary can be distinguished by its black chevrons.

Where to see a pearl-bordered fritillary

With a preference for coppiced or recently clear-felled woodland, sun-dappled rides and clearings, and mosaics of grass, dense bracken and light scrub, this butterfly has declined alongside traditional woodland management practices. Its caterpillars rely on common dog-violet, which thrives in open areas where the surrounding vegetation can’t shade them out. 

8. Brown hairstreak (Thecla betulae)

This tree dweller flits around the tops of prominent ash trees along woodland edges, feeding on aphid honeydew. It has deep brown wings, with an orange splash on its forewings and small orange ‘tails’ on its hindwings. Its underwings are a stunning orange-brown with two wavy white lines. You could spot it on the wing between July and September.

Where to see a brown hairstreak

Though it spends most of its time up in the canopy, the female brown hairstreak will venture down to young blackthorn shoots to lay her eggs. This makes the butterfly extremely vulnerable to intensive land management practices such as hedgerow removal and annual flailing, which removes its eggs. The brown hairstreak is now so rare it’s found only in southern England and Wales, and mid-west Ireland.