Brown hairstreak butterflies found on 6 Worcestershire reserves

Brown hairstreak butterfly. Credit James Hitchcock.

September 2009. A nationally rare butterfly has now been found on six reserves owned by Worcestershire Wildlife Trust.

Eggs of the brown hairstreak, a small and elusive butterfly, have recently been found on blackthorn at Feckenham Wylde Moor reserve, four a half miles from Redditch. Brown hairstreak eggs have been found previously at nearby Grafton Wood, Stockwood Meadow, Trench Wood, Humpy Meadow and Foster's Green Meadows National Nature Reserve

Fly in tree canopies
Brown hairstreak butterflies usually fly in the canopies of trees and are rarely seen by most people. The females are most frequently seen as they descend to hedgerows in late August and September looking for suitable egg-laying spots. They often congregate around one tree known as an assembly or master tree, often ash, to feed on aphid honeydew although they're occasionally found lower down feeding on common fleabane and bramble.

Brown hairstreak eggs on blackthorn. Credit Paul Meers.

"This is a really exciting find as we haven't seen brown hairstreaks on the reserve for the last ten years. The work we've been doing to encourage new blackthorn sucker growth on this reserve and across the area is obviously working."

Habitat management
Management work at Feckenham Wylde Moor has involved cutting back the blackthorn a little each year to suit the brown hairstreak need for two-four year old growth and a fork of the bush to lay its eggs in. It's possible that cattle browsing of blackthorn may also have helped.

It was hoped that by working with landowners at a landscape level, rather than on isolated individual sites, the butterflies would have a network of hedgerows, trees and shrubs through which to move in order to colonise a wider area. It is now clear that this approach, part of the Wildlife Trust's Living Landscapes vision, is working for brown hairstreaks.

James Hitchcock, reserves officer for Worcestershire Wildlife Trust, said "We've been working across our reserves and with Butterfly Conservation and landowners in the area to improve the management of hedgerows for butterfly species in general and brown hairstreaks in particular.

"Living landscapes is all about creating a network of areas and corridors to give our wildlife the chance to move through our countryside. As climate change starts to affect what food sources and habitats are available at certain times of the year, our wildlife needs the freedom to adapt to the changes by moving to find new food and habitats."

The news comes after a recent butterfly survey in Grafton Wood, 6 miles from Worcester, demonstrated that butterfly numbers were up significantly on previous years. Grafton Wood, jointly owned with Butterfly Conservation, is the stronghold of the brown hairstreak butterfly and is the centre of the only colony in the Midlands.