T he autumn sun cast a coppery glow over the long meadow, the merest icing of early snow clung stubbornly to the long grass. Overhead, a pair of magnificent red kites wheeled majestically before disappearing into the trees.

The only reminder of civilisation in this haven of tranquillity was the distant whine of a jet outbound from Heathrow. This was the Warburg reserve, the flagship reserve of the Bucks, Berks and Oxon Wildlife Trust.

Located in a valley just outside the village of Bix, near Henley, the Warburg lies at the end of a narrow, winding and seemingly endless lane. It was named after the distinguished botanist Dr EF Warburg of Oxford University. Known universally as Heff, his speciality was mosses. Tragically, he died young at 58, just before the reserve was bought.

My guide and mentor was trainee warden Catherine Tongue. As we walked the paths and byways, she described both the reserve and the wildlife BBOWT nurtures and supports there.

Covering 265 acres, the nature reserve is a mix of ancient woodland — more than 400 years old — secondary woodland and chalk grassland. BBOWT has created two artificial ponds, complete with hides, so visitors can observe dragonflies, damselflies and other insects performing aerobatics above the water.

In summer, the meadow through which we were strolling is a riot of wildflowers, including marjoram and thyme. Elsewhere, depending on the season, there will be orchids, hellebores, anemones, chiltern gentians and bluebells. These bluebells are particularly evident in the ancient woodland, providing a truly magnificent spring carpet to delight the eye.

Warburg is home to a huge variety of fungi and collectors often visit to gather samples.

The geography of the valley means that cold air sinks to create breathtaking hoar frosts in winter.

Fauna come in all shapes and sizes. The threatened dormouse is well looked after, with nest boxes distributed around the site. Their population is checked not only by observing the nest boxes, but with hair traps, too. Hair traps are cardboard tubes containing strips of sticky tape. A visiting dormouse will leave behind a tiny clump of fur as evidence of its presence. Plus, as warden Giles Alder told me, dormice love hazelnuts and nibble them in a particular way.

Songbirds are in abundance, including goldcrests. Tawny owls add their hooting to the dusk chorus. At dusk pipistrelle and noctule bats can be seen swooping in search of their insect prey.

“Where it is safe to do so, we leave old tree trunks. They are full of holes and cracks that bats like as shelter,” Catherine explained.

There is also a hibernaculum for the bats’ winter hibernation, created by roofing in the target area of an old rifle range on the site.

A haven for the raptors, sparrowhawks and kestrels have free rein, vying with red kites for prey.

“Now that red kites are no longer persecuted by gamekeepers, their numbers have grown substantially” said Giles. “You can see them all over the Chilterns.”

The badger population is strong and in spring, the Warburg staff organise badger watches.

One species for which Warburg recreates habitat is the adder. Once seen in their hundreds, loss of the grasslands where they can bask and watch for their prey means adders are now yet another threatened species. Warburg staff calculate they have about 20 on the reserve.

Catherine pointed out areas which are to be cut back to grassland. Flocks of sheep and herds of cattle are grazed in rotation to keep grass short and prevent a relapse to scrub.

Aided by some 30 volunteers, Giles and Catherine have a constant cycle of maintenance and new work in cutting brush, scrub and grass, pruning and felling trees. Some logs are left in small piles to encourage invertebrates and mammals, many are used as fuel. A hurdler makes good use of the timber in his work.

The Warburg reserve is open all year round and caters for the disabled. One of the ponds and its hide has disabled access. An electric buggy can be borrowed from the centre and taken on certain of the smoother paths. Each of the gates has an ingenious two-way catch that allows a disabled person to push open the gate, which then swings shut.

The Warburg reserve was BBOWT’s first land purchase in the 1960s, thanks solely to the efforts of Vera Paul. Schoolteacher Vera was a passionate naturalist and a founding member of BBOWT. She single-handedly raised the money for the purchase. One novel method was to take the telephone directory, then look for any house name with a wildlife or nature connection. Each of these then received a call inviting a donation to the cause.

Philippa Lyons has been chief executive of BBOWT since 2004 and discussed the changes in the trust’s modus operandi.

“We now have 83 reserves across all three counties and that makes us one of the biggest wildlife trusts in UK. We have actually reduced the number of reserves by disposing of small isolated units and enlarging the bigger ones. We buy up the land in between two large sites to make one larger reserve,” explained Philippa. “One fundamental change has been to integrate full-time staff and volunteers. BBOWT has about 60 full-time staff and 1,200 volunteers. Of those, 100 or so are key volunteers, highly experienced. Some of them act as reserve wardens. Many of the volunteers have been with us for 20 or 30 years, they are vital. Now we operate as one team, no dividing lines.”

Cooperation and partnership have become the watchwords for the trust. It concentrates efforts so that grants and help go to identified and designated sites, such as land surrounding reserves, so that habitat is maintained. It works closely with organisations like Defra and Natural England.

Land draining into the Thames has been altered so that instead of acting as water meadow to absorb floods and giving slow outflow, it drains rapidly. BBOWT is working as part of a team to reverse these alterations, helping not only flood relief, but also recreating habitat for water fowl.

Of last year’s £3.3m income, £1.8m came from the 25,000 memberships, £500,000 from donations and legacies, and £1m from company donations and grants, including the National Lottery. There are some monies from the Landfill Community Fund, using part of the landfill tax towards environmental schemes.

Truly, the BBOWT motto says it all: ‘Protecting wildlife for the future’.

For great days out, volunteering and membership call 01865 775476