High brown fritillary  (Argynnis adippe)

Classified as Vulnerable in the UK.

This large and attractive butterfly has orange upperwings chequered with black, and pale green hindwings with mottled white, black and orange markings. The caterpillar is dark pink and covered in spiky hairs.

The high brown fritillary is found across most of Europe except for the extreme north. In Britain it used to be found in England south of Cumbria, and across all of Wales. It is now restricted to just fragments of its former range, at sites in Devon, Herefordshire, parts of Wales and the region around Morecambe Bay.

This is a butterfly of woods and associated scrubby places. It requires warm, sunny, bracken-covered slopes with an abundant population of violets, the caterpillars' food plant, for egg- laying. The high brown fritillary is now confined to two different habitats in Britain. In the north the butterfly favours limestone woods and scrub. In the south of its range it is found in association with bracken-covered slopes.

The high brown fritillary appears in late June and is on the wing until early August. Whilst active it covers a lot of ground unlike many other species of butterfly, which tend to confine themselves to areas of no more than a hectare.

The butterfly feeds from the nectar of bramble and marsh thistle and is a rapid flyer between favoured feeding grounds. Females seek out warm slopes on which to lay their eggs. The egg overwinters and the caterpillar hatches in April or May to feed on violet leaves. They also need warm, sunny spots in which to develop prior to pupating in the leaf litter around the roots of bushes and scrub.

The abandonment of coppicing as a woodland management technique has led to major reductions in the numbers of the high brown fritillary. Coppicing produces open ground within a wood and warms up the soil, creating ideal conditions for the various species of violet favoured by the butterfly. Although coppicing is being revived as a conservation management tool, there are also problems associated with the increasing deer population browsing on the new shoots.

Where the butterfly is dependent on warm, bracken-covered slopes, the reduction in grazing has allowed bracken to grow unchecked, reducing the ground temperature and building up a deep litter that chokes out the violet. Agricultural improvement of these slopes has also taken place in many areas, eliminating both the violets and the warm habitat provided by the bracken. Many slopes have also been subjected to planting with conifer trees.

The scarcity of the high brown fritillary led to its inclusion in English Nature's Species Recovery Programme. In partnership with Butterfly Conservation and the National Trust, surveys were carried out to ascertain the levels of population in the butterfly's three main areas.

The Species Action Plan for the high brown fritillary recommended management techniques for the two differing habitats where the butterfly still occurred. For the woodland areas, a return to traditional coppicing methods was suggested, coupled with deer management to reduce the overbrowsing problem. The coppice technique was also to be applied to dense scrub around warm, sunny rock outcrops. Bracken management revolved around reducing the invasion by scrub, re-introducing grazing to create bare patches within the bracken stands, and removing dense bracken litter where possible. As part of the grazing regime, ponies were used to provide winter grazing, supplementing cattle grazing over the summer months. Paths were also cut through the bracken to provide patches open to the warmth of the sun and, therefore, suitable for egg-laying.

The butterfly is still by no means common, but with improved management it is hoped that this attractive species will regain its numbers and begin re-colonising areas from which it has been lost.

• Coppicing: traditional form of woodland management in which trees are cut close to the base of the trunk. Re-growth occurs in the form of many thin poles. Woodlands are cut in this way on rotation, producing a mosaic of different stages of re-growth.
• Pupating: the process of becoming a pupa, the stage of an insect's development, when huge changes occur that reorganise the larval form into the adult form. In butterflies the pupa is also called a chrysalis.