Deer fences are often necessary to allow trees and other vegetation to grow despite massive grazing pressure. However, they also pose a serious threat to birds such as capercaillie and black grouse. Where deer fences are no longer needed we remove them. This article is not intended as a comprehensive guide to the dismantling of fences. If you are planning to partake in fence removal, we recommend that you receive appropriate training, or work under the guidance of a trained supervisor (eg on a TFL Conservation Holiday!).
It can be a real challenge getting trees to grow in the Highlands. Loss of predators, winter-feeding of deer and milder winters have all contributed to a huge rise in deer numbers, leading to pressure on any young trees growing in a largely denuded landscape. This is easy to observe in many places where deer and sheep have been excluded for a few years: with a suitable seed source nearby and suitable ground conditions, trees will flourish. Of course it is not only trees that suffer from overgrazing - many other plants, such as various wildflowers, mosses, heather and shrubs can also be suppressed.
Deer fences have long been a part of forestry practice in the UK. Deer numbers are so high that without fences it would have been impossible for foresters to establish timber crops. Many native woodland restoration schemes also rely very much on fences to keep hungry mouths away from the regenerating vegetation. Again, this is often essential for allowing woodland to recover.
However, fences don't come without a price. A number of birds, particularly the black grouse (Tetrao tetrix) and the capercaillie (Tetrao urogallus), which are both kinds of woodland grouse, have the habit of flying at a low level when startled, making quickly for the cover of the forest. Unfortunately, they often don't see fences, and collide with them - with lethal consequences.
Both the black grouse and the capercaillie are in serious trouble, as a combination of factors - including wet summers and loss of their habitat - are contributing to an alarming population decline in the UK.
As well as the danger to these (and other) birds, fences can create unfavourable conditions, as the complete exclusion of grazing wouldn't usually occur in a natural setting. It sometimes occurs that trees have difficulty regenerating when the sward becomes particularly dense due to undergrazing. There's no doubt that fences play a crucial role in the recovery of native woodlands, and in some senses they can be seen as a 'first aid' response to overgrazing: essential in the short-term, but not a long-term cure. Furthermore, in an aesthetic sense fences can be quite intrusive in the landscape.
Addressing the problem
So while fences are still clearly necessary, what can be done to deal with this conundrum? For a start, we can remove all redundant fences - and there are plenty of them! Many forestry plantations were established using a large external fence, with a number of internal fences to help control deer in different compartments. As many of these fences have now served their useful purpose, they can be removed, without posing any risk to the trees.
Over the years, many of our hard-working volunteers have removed tens of kilometres of fence on our Conservation Holidays. For example, in the 1990s, we dismantled substantial amounts of redundant fencing on the south side of Loch Beinn a' Mheadhoin in Glen Affric. At the time of writing we have almost finished dismantling the 20 km fence around Portclair Hill above Loch Ness. While removing the fence, we occasionally come across the lyre-shaped tail feathers of black grouse that had hit the fence. This, along with a small dent in the fence, is often the only sign of a bird strike, as scavengers usually remove the carcasses soon after they are killed. It is a poignant reminder of the danger fences can present.
What follows is a glimpse into the work our volunteers carry out and is not intended as a comprehensive guide to the dismantling of fences. If you are planning to partake in fence removal, we recommend that you receive appropriate training, or work under the guidance of a trained supervisor (e.g. on a TFL Conservation Holiday!).
The practical work of fence removal
It is obviously important to be properly equipped for taking down a fence, as it can be a potentially hazardous task. Top on the list of personal protection equipment are safety goggles. While every effort should be made to cut and move wire safely, sharp pieces of springy wire can move at high speed and could cause devastating eye injuries. Tough leather gloves are needed to prevent puncture wounds from rusty wire, while hardhats are essential when taking out posts. We also supply a range of tools, including fencing pliers ('friends'), bolt cutters and hammers.
Once the team are kitted up, and the safety briefing and work demonstrations have been given, the business of dismantling can begin. The order in which things are done is critical for efficiency and safety. The structure of a fence can vary, depending on how old it is. Modern deer fences are usually 1.8 metres (6 feet) high and consist of two widths of netting, one above the other. These are attached to wooden posts using U-shaped staples. There are also strands of high-tension strainer wire running along the top, middle and bottom of the fence. These are attached to the netting itself with lashing rods, which are short spirals of wire that have been nicknamed 'twizzles'!
Occasionally there is a piece of barbed wire running along the top of the fence. To begin with, this is removed to make it easier and safer for everyone else to work. Removing the twizzles (de-twizzling!) from the middle of the fence is the next job, followed by the removal of staples from the top section of fence. When a manageable length has been detached (up to 100 metres, depending on the terrain), the fence is cut with great care and rolled up. The bottom section can then be removed. It is a good idea to remove them in two stages, so that the top section doesn't collapse down, on top of the people taking staples out of the bottom section.
Taking down a fence is one of those tasks that makes most sense when it is directly experienced. Within half an hour of starting everyone seems to find his or her niche. People often comment on how much of a team effort it is, taking down a fence. Every job is crucial, from more intricate tasks such as twizzle and staple removal, to more strenuous activities like pulling out fence posts, and rolling and moving the netting.
In a day a group may take down over 500 metres of fence - this represents a significant reduction in the danger to the birds in the area. When we have dismantled a fence, we aim to remove as much of the material from the site as is practical. This is to ensure the area is left as safe and as natural-looking as possible.
Staples and twizzles are put into a container, and the fence posts and rolls of netting and line wire are taken, where possible, to the nearest road for later removal. If the material is in good condition, we sometimes re-use some of it to create small stock-fenced exclosures to protect riparian vegetation, aspen trees we've planted, or to create plots that allow grazing levels to be monitored.
However, in many cases, the site may be so remote that removing hundreds of kilogrammes of material by hand is neither safe nor practical. In these cases the materials are left in neat piles on the hill. Every few years the Forestry Commission arrange for a helicopter, which may be in the area anyway doing other work, to pick up the materials and remove them from the forest.
Alternatives to fencing
What of the fences that remain? Obviously there is a strong case for having fencing in some areas to help woodland to regenerate. When fences are put up, care needs to be taken to avoid key black grouse areas, and fences should ideally be positioned in such a way that they are more visible to the birds. Furthermore, fences can be made more conspicuous with markers. Various types are used, including wooden 'droppers' (thin poles), or in some cases orange plastic netting, although obviously the latter is less visually appealing. Both of these methods are very effective at reducing bird strikes.
As high deer numbers are a principle threat to forest regeneration, a key strategy is to reduce deer numbers by shooting. At Creag Meaghaidh in Inverness-shire, Scottish Natural Heritage managed to achieve huge amounts of regeneration largely through deer control, without any fencing at all.
At their Corrimony Nature Reserve near Glen Affric, the RSPB have been very successful at increasing black grouse numbers along with native woodland cover, with help from TFL volunteers. All deer fences (ie the six foot high variety) have been removed, or reduced in height to that of a stock fence. When this is combined with an electric fence a short way beyond the stock fence, it helps to exclude deer, while the reduced height dramatically reduces the threat to wildlife. Deer can still enter the reserve from one side, but their numbers are kept low enough for regeneration to take place.
So while we continue to erect fences in carefully chosen locations, removing those that are no longer useful can be a very rewarding task. It is just one of the contributions our volunteers make towards re-wilding the Highlands.