On grey, damp, wintry days the little wildlife that’s around in the woods keeps a low profile. But the scuffle and thump of a muntjac deer breaking cover, head down, trotting like a dog into the nearest undergrowth, or a family of roe deer standing silently watching me, can lift the spirits like nothing else.

Ten years ago encounters like these were few and far between, but not today. Without us being aware of it, there’s been a population boom in the countryside. It is difficult to gauge how many deer live in the UK, but what is clear is that they have expanded their ranges and increased in numbers fairly rapidly for many years.

Woodland deer are territorial, and will feed and lie up in a home range that can include woods and fields. When numbers increase, they use up all the available food and then range further afield. This is often when they come into conflict with vehicles on roads.

The increase in deer population may seem to be a natural phenomenon, but of course man has had a hand too. We removed natural predators, such as wolves, from England’s woods, and introduced Japanese sika and Asian muntjac deer into the countryside. New frost-resistant arable crops such as oilseed rape and kale provide tasty food supplies in winter. Without responsible control on their numbers, deer may eat themselves out of house and home. As the numbers spiral upwards the impacts start to be damaging, and keeping the numbers at a natural level is the sensible response.

Culling deer, which means shooting a certain number each year, is, in the long run, a kind act.

A managed deer population is healthy and less stressed, and the woodland habitat they live in is healthier too.

A low density of deer in woodland is beneficial because they keep vigorous plants like bramble under control, and maintain open patches and woodland glades for more birds and butterflies.

Recently I visited a wood near Oxford for the first time. It’s a protected site for nature, a status enjoyed by only two per cent of Oxfordshire’s land area, so I was expecting something pretty good. It wasn’t long before disappointment set in. A damaged wood is a depressing place. This one looked as if someone had released a herd of pigs. Muddy tracks led off in all directions and the ‘browse line’ was so marked that not a leaf could be seen below my chest height. The hazels that grew in abundance had no young shoots and the bark was systematically being rubbed and chewed off the older stems, slowly killing the trees. This was a wood without a future.

We have seen similar devastation in BBOWT woodlands too. Apart from the deer we see on walks, the droppings and well-worn tracks through the trees are giveaway signs of a growing herd.

The views through the trees are getting longer too; by stooping to three or four feet it’s easy to see hundreds of yards because the foliage and young growth below this height have vanished.

In some woods we have fenced off areas and protected coppiced trees. Within a season we’ve noted the changes as the primroses, dog’s mercury and bluebells thrive inside the protected areas, while the woodland floor outside has nothing but grasses and cleavers. Managing deer across Oxfordshire is a landscape-wide challenge that needs to be faced by all landowners. In the Bernwood Forest area, between Beckley and Brill, BBOWT has set up a new project to try to reduce the numbers of deer; this will allow the woodlands and meadows to regenerate for other wildlife.