Brown hairstreak

What is the Brown hairstreak?

The brown hairstreak is a localised, uncommon butterfly with a stronghold in central southern England. It is a small butterfly, with brown upperwings and small ‘tails’ protruding from the hindwings. Females have a brilliant orange patch in the top corner of each forewing. Brown hairstreaks often rest with their wings closed showing distinctive bright orange underwings with two white lines streaked across them.

Why is the Brown hairstreak important to the Surrey Hills?

The brown hairstreak is protected under the Wildlife and Countryside Act (1981) and is a UK Priority Species for conservation. It has declined by 49% since the 1970s and is restricted in the UK to three main areas: south-west Wales, Devon/Somerset and Surrey/Sussex. The main reasons for its decline are hedgerow removal and the annual flailing of hedges, which destroys its eggs.

What habitat does the Brown hairstreak like?

Hedgerow

Hedgerows are important both as landscape features and as wildlife habitat across lowland Britain, especially when associated with features such as grassy field margins. Classic hedges are linear, shrubby, mostly continuous features though hedges which have developed into lines of trees retain landscape value and some wildlife value. Over 600 plant species, 1,500 insects, 65 birds and 20 mammals have been recorded at some time living or feeding in hedges and they are especially important for butterflies and moths, farmland birds, bats and dormice. They also play a crucial role in landscape connectivity, linking up other areas of habitat so that wildlife can move more freely across the farmed landscape.

As blackthorn is often a major component of lowland farm hedges, the presence of brown hairstreak indicates a healthy hedgerow habitat.

What can be done to benefit the Brown hairstreak?

Good hedgerow management for this species will create/result in big, dense native hedgerows which include frequent blackthorn in the species mix and are cut in a management rotation which retains seeds and berries as winter food resources for wildlife. This management will benefit many farmland birds, in particular winter visitors such as fieldfares and redwings.

Opportunities to create/improve/extend suitable habitat for this species include:

Restoring overgrown/neglected hedgerows by coppicing, hedge-laying and planting up gaps

Extending the hedge management cycle to allow hedges to grow taller and wider, and hedgerow fruits and berries to ripen
Planting new hedgerows, including blackthorn in the shrub species mix

Creating and managing areas for the Brown hairstreak will help deliver the following benefits to communities:

Clean water
Clean air
Protection from and mitigation of environmental hazards
Mitigation of and adaptation to climate change
Thriving plants and wildlife
Beauty, heritage and engagement

These illustrations are by an artist taking part in a programme delivered by Watts Gallery Trust and funded by the Michael Varah Memorial Fund. This series of 30 Surrey Hills Indicator Species were commissioned by Surrey Hills Society and funded by Surrey Hills Trust Fund as part of the Making Space for Nature Exhibition.