Deer are a natural part of our woodland ecosystems. They fulfil an important ecological role in diversifying woodlands. They open up glades, recycle nutrients, spread seeds in their dung and create space for young trees and plants to grow into. However, in many parts of the Highlands, browsing pressure from deer has become out of balance with vegetation growth, so that sustained browsing is preventing young trees from becoming established.
Overall populations of red, roe, sika and fallow deer in the Highlands have grown steadily since at least the 1960s[i], annually increasing the pressure on tree cover. In the areas where deer populations are too high, habitats and the wildlife which depend on them are degrading year on year, to the point that even the deer themselves are finding it harder to put on body weight. The result is that the ecological potential of the Highlands is all too rarely realised. Deer have become a landscape-scale suppressor of ecological processes in the Highland ecosystem.
Reducing deer pressure across large areas would kick-start the development of a wider variety of natural vegetation and habitats[ii] across much of the Highlands. We do not expect, and would not wish to see, woodland habitats developing everywhere. Instead, large, open expanses of peatland, heath and grasslands would, together with woodlands and scrub, form a rich mosaic of habitats, with vegetation dispersing naturally from seed sources.
As a rough guide, natural regeneration rarely takes place where deer populations are higher than five deer per square kilometre. While this will vary with a number of habitat and environmental factors, the scale of deer reductions required will be very significant in many areas. It is widely believed that this could add to the financial stresses experienced by Highland estates, many of which currently act as foundations for fragile rural economies by attracting stalking clients who bring business to accommodation and other local services which are linked into wider supply chains[iii]. However, we believe these stresses can be short-lived and that new approaches to deer management can lead to a greater range of new business opportunities in the medium and long term. Moreover, deer thrive better at lower densities and there is a reliable and early prospect of bigger, healthier and higher value deer[iv], especially as the woodland ecosystem develops.
On our own ground, we use three tools for managing deer and we advocate using these in different combinations to suit different circumstances. Deer management needs to take place over large areas, so communication and collaboration between neighbouring landowners is essential if these tools are to be effective and sustainable in the long term.
Understanding the relationship between habitat deer allows the use of these tools to be varied to move us towards the outcomes we want to see. We use a method of herbivore impact assessment to look directly at how much growth has been removed from a tree by browsing since the last growing season. It also allows an interpretation of the extent to which growth has been affected by browsing in previous years, so it is a very informative way of understanding the relationship between vegetation development and browsing. This allows us to judge whether or not we need to take action to reduce deer pressure to meet our aims.
As well as monitoring deer impacts, it is important to monitor the deer populations themselves. Deer counts, coordinated between neighbouring landowners provide useful snapshots of numbers and distribution. They can also provide information on calf survival and hind fecundity, which are key to understanding population recruitment rates. Understanding the movement of deer throughout the year is an important factor in management and detailed discussions among landowners are a good way to build this into collaborative deer management. Larder records are another key source of data, simply recording basic information like sex, broad age category, and carcass weight is a useful way to get an indication of how deer are faring on the habitat available.
Deer management polarises opinion in Scotland. Deer affect our environment, our sense of place, our enjoyment of the landscape and our rural economy in both positive and negative ways. The debate about these effects, and what we should do about them has led to discord between people on different sides of the argument. The conflict between sporting and conservation interests is now long-established, with trust and respect in short supply. We are mindful that there is much to learn about deer and their management in Scotland, so we will take this on board as research and learning brings greater knowledge into play.
We want to help find a basis for open, positive conversations with others about the most beneficial approach for the future, building on the new knowledge being brought into play from ongoing research about deer and their management. We remain open to new evidence that would contribute to our approach, and we hope others will take the same approach. We respect the fact that most people’s views are founded in a strong set of values and believe that these values are often closer than is apparent on the surface. It is our hope that a shared passion for, and delight in, the land, the prosperity it brings, its cultures and its wildlife can still bring the different sides of this debate together in finding a shared way forward.
[i] Scottish Parliament Information Centre (2013) Wild Deer in Scotland. http://www.parliament.scot/ResearchBriefingsAndFactsheets/S4/SB_13-74.pdf
[ii] As can be seen at places like Creag Meagaidh National Nature Reserve, Glen Feshie and Mar Lodge.
[iii] ADMG (2016) The Contribution of Deer Management to the Scottish Economy. http://www.deer-management.co.uk/wp-content/uploads/2016/02/Final-25FEB.pdf £140 million of expenditure in Scotland is related to deer management.
[iv] See for example Corrour Environmental Fact Sheet (2015). http://www.corrour.co.uk/the-estate/environmental-fact-sheet/
Sign up to our free monthly e-newsletter, Tree News. It's the perfect way to keep in touch and stay up to date with the latest news about Trees for Life, wildlife and conservation.
In 2012 we planted our millionth tree! Now we want to establish a million more trees. Help us meet this exciting milestone...
Join Trees for Life and receive our exclusive members magazine!
Live locally and want to know more about volunteering with us? Get updates about our Conservation Days straight to your inbox.