Dorset’s hidden wonder
Colin Varndell reveals the natural splendours to be found at Butterfly Conservation’s Alner’s Gorse reserve
Published in June ’11
The first time I visited Alner’s Gorse I found it surprising how the entrance from the road between Hazelbury Bryan and King’s Stag was so inconspicuous. I had passed it many times, but had no idea what a feast of nature was hidden behind its high hedges. In fact, despite having map references, I drove past the entrance twice before I identified it. Once found, I have since returned on numerous occasions; it is a place that always fills me with excitement and anticipation whenever I visit. The reserve is full of surprises and, as you turn into rides and paths, different species of wildlife appear.
From the moment you walk through the gate you are aware that you are entering another world, far from modern, noisy society. This is a magnificent relic of the ancient Blackmore Vale Commons, a world of rough, scrubby grassland, dotted with oak trees and thickets of wild shrubs – a living remnant of times past. The site is owned and managed by Butterfly Conservation and, although primarily it exists as an insect reserve, there is a wealth of other wildlife to be seen and enjoyed.
A narrow strip of ground, lined with a procession of large-leaved lime trees, leads you downhill to the main reserve. At the end of this track, the area opens out into a broad, level topography of rough grassland, sprinkled with gorse and blackthorn thickets and many interesting tree and shrub species, including spindle, alder buckthorn and a healthy population of young oaks.
The population of roe deer here is quiet and secretive and, for most of the day, remains hidden in the woods. The roe browse the lush undergrowth at dawn and dusk, coming out of the surrounding woodland where they lie up during daytime. There have been occasional sightings of a fox sloping across one of the wide tracks, no doubt hunting the small mammals which occur here, including common shrew, woodmouse and both bank and field vole.
The range of bird song in spring is a sheer delight; willow warblers and blackcaps swell the ranks of resident birds like songthrush, wren and robin. Woodpeckers regularly drum on hollow branches in spring, their loud rattle carrying far across the reserve. The rasping alarm calls of jays alert the neighbourhood to any likely predators including humans. The songbirds mostly nest within the relative safety of the tangled bramble thickets in spring or in the gorse and hawthorn hedges. Green and great spotted woodpeckers both breed in the woodlands here; the former are frequently seen in areas of short turf where they probe for ant eggs. Barn owls breed nearby and are often seen gliding silently over the grassy rides, on thistledown wings, on summer evenings – another predator of the small mammals that thrive in the rough grassland.
Adders are abundant here and may be seen basking on the sunny banks and woodpiles. One herpetologist I met at the site claimed to have seen eighteen individual adders that day. The log piles are also ideal habitats for the common lizard. In high summer, it is not unusual to find entire families of small, young lizards basking on the sun-heated logs amongst the scrub, but you have to be stealthy, because if they see you first you don’t see them!
The swathes of summer colour in the rides are impressive with a vibrant mix of native wild flowers including knapweed, agrimony, betony, fleabane and sneezewort, all rich in nectar to attract the wealth of insects. In fact, of all the rich tapestry of wildlife occurring here, it is the insects that take pride of place. Southern hawker dragonflies patrol the rides in their indomitable pursuit of quarry. Brimstone butterflies flutter along the woodland edges in spring in a vague impression of sulphur yellow. To catch sight of the brown hairstreak is a special prize. Seldom seen elsewhere in the county the brown hairstreak thrives here along with its close relatives the purple hairstreak and white-letter hairstreak.
n high summer silver-washed fritillary butterflies visit the bramble flowers on sunny days. Along the bottom edge of the reserve I remember one visit when with every step another beautiful silver-washed fritillary could be spied sunning itself, or taking off to find another patch of bramble nectar. The distinctive valezina also showed itself in the wooded glades, rarely going far from its favoured patch of flowers. Each time you wander along the flower-rich pathways you can’t help but be thrilled by the sheer quantity of butterflies skimming along on their animated tissue paper wings, including comma, gatekeeper, clouds of marbled white, peacock, painted lady, ringlet, red admiral and various skippers.
Around one fifth of all the UK moth species have been recorded on Alner’s Gorse, which is, in itself, a testament to the quality of the reserve and its flora and, during the summer months, regular moth-trapping events are organised here. The Butterfly Conservation website gives details of which events are open to the public.
Butterfly Conservation manage the grass areas on the reserve to encourage the population of marsh fritillary butterflies – formerly abundant in the area, but now recognised as an internationally-threatened species. The overall aim for the reserve is to maintain a balance of rough dry and wet grassland, interspersed with patches of scrub and trees. To this end, hardy ponies casually graze the rides and tethered goats are also used to great effect where the conditions and height of the sward are critical for the benefit of other flora and insect life. In order to prevent the trees from maturing, which would change the habitat to high forest, a regular cutting regime is also carried out.
Off the beaten track and with a steep, rough track to approach, Alner’s Gorse is a backwoods wilderness. It is not a place where you will encounter the casual visitor, but most humans you do meet will eagerly tell you of their sightings. Wear wellies, tuck your trousers into your boots, prepare to spend far longer than you have available, and you should have the most incredible experience – all