On the hunt for our missing butterflies

Kieran Falconer joins a Hampshire conservation group trying to reverse crucial habitat damage

When I was a child, I clearly remember, butterflies used to flutter about my head. Cabbage whites among my uncle's veg, red admirals when I went blackberrying and then whole days spent in vain, chasing peacock butterflies with a net made mostly of holes. The result was nearly always agony, largely due to the nasty combination of stinging nettles and short trousers, but despite the physical pain, butterflies remain, for me, the effervescent symbol of summer.

Wandering in woods over the past few miserable months I've sorely missed them. Butterflies can't fly in the rain, which means no food or sex for the little flitters. But there is a longer-term threat than a rainy summer: climate change, intensive farming and a dwindling green belt have led to shrinking breeding areas and extinction for some varieties in the past 20 years.

So I was pleased to hear that Butterfly Conservation – Europe's biggest insect conservation organisation, currently celebrating its 40th anniversary – has recently received a lottery grant of nearly £1m to improve butterfly and moth habitats. This was all beautifully illustrated in their magazine – Butterfly – a copy of which I found at the Hotel du Vin in Winchester. Although I didn't realise it, the area around my hotel is a prime lepidoptera haven. Between Winchester and Salisbury is Bentley Wood – lying within the larger Tytherley Woods – with the best selection of rare species in the UK. This hallowed spot is where I meet Dr Dan Hoare to discuss how they will use the grant.

Hoare is not what you would expect of a conservationist. He's young, has no beard and no hint of Birkenstocks. He's also remarkably optimistic which is not something you get to hear in his trade very often – and he doesn't speak in jargon. His full title is senior regional officer for the South-east for Butterfly Conservation (BC): Mr Butterfly from Kent to Hampshire.

"The great thing about butterfly watching," says Hoare as we walk along a path in Bentley Wood, "is that you don't have to get up early like bird watchers. Butterflies need at least 17C to start flying and that means they're not about until 10am and then at their most active at midday and in the afternoon when it's hottest."

Bentley remains the best place in the UK to spot the purple emperor, the biggest native species and one that gets devotees visiting from all over the world. In July, fans try to attract "His Majesty" with salty bacon and molasses treats. By September, the emperors have probably gone to the empire in the sky.

Butterfly life is short – four to six weeks – but they can reproduce two or three times in a season. Different species occupy different times of the year so there is plenty to see from March to October. September and October can be useful visually because, although there are fewer butterflies, the coolness means they stay still for longer so that you can see the detail on their wings. In summer you may have clouds of them ceaselessly zooming about but their detailed beauty is hidden in a blur of colour.

Until recently, butterfly reserves have been on a small scale, but a few acres of protected habitat among a sea of farms have a limited effect. If a butterfly strays from the reserve it might not find any flowers for nectar and it would perish. The area around a small conservation spot can be a desert.

To counter this, the BC and its many volunteers (it has 12,000 members) are taking the message out and enlarging the conservation area to include farms, graveyards and even that scourge of the environment, golf courses. The 1,828 acres of Bentley Wood will soon expand to 180,000 acres of sustainable habitat. Effort has been made to interest farmers (who get government grants) to set aside a five-yard fringe of land around their fields for alluring habitat. "This area will contain wild flowers and insects," says Hoare, "so butterflies aren't the only winners."

For the butterfly spotter, this means that next spring and summer should have thousands of wings trembling on petals and leaves. We visit another reserve just east of Winchester. Unsteadily, I descend the steep chalk of Magdalen Hill Down. The wind is fierce at the top, but we slip down the slope and soon hear the A31 in front of us. Despite this, we are treated to a wonderful meadow of ox-eye daisy, and my fingers soon smell of wild marjoram. This is food for the butterflies: meadow brown, chalkhill blue and common blue. A freshly painted peacock just out of the pupa lets its crisp new colour receive the sun. Overhead swallows dance in the uncommon blue. It is finally more than 17C.

COMPACT FACTS

How to get there

Hotel du Vin in Winchester (01962 841414, hotelduvin.com) offers doubles from £135 per night.

Further information

'Pocket Guide to Butterflies of Great Britain and Ireland', Richard Lewington (British Wildlife Publishing, £9.95).

Butterfly Conservation (01929 400209; butterfly-conservation.org)

Winchester Tourism (01962 840500; visitwinchester.co.uk).