At Watchtree we are very fond of our resident Roe Deer, they are a highlight sighting for many of our visitors and as they become more at ease around people, we are increasingly able to observe their natural behaviour and even some individual characters. They are wonderfully photogenetic making them a regular inclusion in our annual wildlife photography calendar.
Did you know that the Felix Salten’s 1928 book ‘Bambi’ was originally based on a Roe Deer?
About Roe Deer
Roe Deer are a native species to the UK. They are a slender, medium sized deer, adults are around 1.2 metres long and up to 75cm tall at the shoulder. There colour ranges from a dull brown in winter to reddish brown in summer, however they are easily identifiable thanks to their bright, white rumps! Roe Deer have a life expectancy of around 10 years.
Roe Deer are active 24 hours a day, although as they are quite timid, they are most active at dawn and dusk. We often joke that our resident Roe Deer can tell the time as they often appear in the meadows on-mass just after 5pm when all of our visitors have gone home. Members with out of hours access will no doubt attest to this.
Male Roe Deer are called ‘bucks’, they grow short antlers 3 times each year, the antlers first become visible on the buck’s head around November and are covered in a short haired skin called velvet, in spring they shed their velvet to reveal the bony antlers beneath. Later in the year, usually around October or November they will shed their antlers and new ones immediately start to grow in their place. Younger buck’s retain their antlers for longer, often into late December – this can help us to age individuals.
Female Roe Deer are called ‘doe’ and they possess an amazing trick to increase their reproduction success rate. Mating takes place in July and August, but the doe does not begin true pregnancy until January as they delay implantation of the fertilised egg until conditions are more favourable for the baby deer, called ‘kids’.
A healthy doe will usually have twins in May or June although single kids or triplets are not uncommon. Given that Roe Deer have no natural predators besides humans once they pass infancy this can result in a rapidly expanding population in ideal habitat.
Roe Deer population at Watchtree
The truth is, we don’t know exactly how many deer there are here at Watchtree. A reasonable estimate based on regular observation would suggest between 25 and 30 individuals although that number is likely to fluctuate throughout the year.
Roe Deer are solitary animals in summer, but they will form loose herds of 4 to 8 individuals in the winter which use a specific territory. Territories are typically around 1km square and often overlap with neighbouring herds territories. Each herd generally includes a dominant buck, one or two adult doe’s and her kids from the previous summer. In spring those adult does will chase off last year’s kids before giving birth to the new year’s brood. At Watchtree we know there is a territory covering the meadows and woodland strip just to the North of our visitors’ centre.
Additionally, we often see smaller groups of bucks grazing together in winter. These are likely to be younger animals who have not yet established their own herds. They may well challenge the dominant bucks during the ‘rut’ which usually occurs in July and August.
Our resident Roe Deer have no natural predators and are protected from persecution from humans within the confines of the reserve. This means they will have very successful breeding results most years. This could mean that the resident population more than doubles each year, however 5 years ago we estimated 15 to 20 resident Roe Deer so the annual increase has not been that prolific. We suspect that the deer natural control their own numbers due to territorial pressure. It is likely that Watchtree is a haven for breeding deer which are then migrating outside of the reserve and populating other areas where their survival rate may be significantly reduced (due to habitat suitability, road fatalities, hunting etc.).
The Deer Year
The Trouble with Roe Deer
As outlined so far on this page, we love our Roe Deer, but they do create problems particularly as their numbers are increasing and their territories are stretching into every corner of the reserve. With increasing numbers there are more hungry mouths to feed, and this is where the problems begin.
Roe Deer eat a variety of vegetation including leaves, tree shoots/buds, ferns, grasses and shrubs they’ll also seasonal eat fruit, berries, nuts and seeds. Our Roe Deer have taken a particular liking to bird food!
Thankfully, Roe Deer do not strip vast quantities of tree bark which leads to the death of mature trees like Red Deer do. But they will readily graze on young tree buds and saplings. In areas such as scrub, this can be beneficial as we aim to hold the habitat in that underdeveloped state.
In areas where we are trying to create new woodland, protecting saplings from deer grazing is time consuming and very expensive. In a recent project to plant 1500 trees in 1.1 hectares of open field, we spent over £4.5k on tree protection, which is considerably more than we spent on the trees themselves.
In developing woodlands, intense deer grazing can slow down, completely stop or significantly alter the otherwise natural progression of woodland (arguably the presence of Roe Deer is natural, but we’ll get onto that later). Pioneering tree species such as Alder, Willow and Silver Birch grow quickly and have a short life span, they die creating deadwood habitat and leaving space for slower growing climax species such as Oaks to grow in the shelter and protection of the new woodland. Roe Deer will literally ‘nip that in the bud’ by eating those emerging saplings before they get big enough to fend for themselves.
A healthy woodland has good growth and variety at every layer including the woodland floor, shrub layer, understory and canopy. Roe Deer live and eat in the shrub and understory layers. During the harshest months of the year when food is scarce (February and March, known as the hunger gap) there is a visible grazing line in Pond Wood where Roe Deer graze off anything within reach. This becomes less visible as the flush of Spring produces more foliage than the deer can manage, and more food becomes available elsewhere.
Roe Deer have a particular fondness for Bramble leaves, this is an issue as it is now clearly visible in our woodland that bramble growth is being suppressed. Bramble is an important woodland scrub as it provides nesting sites for small birds such as Warblers, Wren and Goldcrest as well as protecting the climax tree species, hence the term the thorn is the mother of the Oak.
Solutions
For many landowners, the fast and simple solution to issues caused by Deer is to cull some or all the offending species in the areas. In many cases this is done strategically, taking specific individuals to reduce the overall population I.e., older breeding females.
However, this is not an approach we wish to instate at Watchtree. We cannot rule it out in the future as it may become essential for the overall benefit of the reserve, but we will not progress to doing so without considerable effort to manage deer related problems with more humane methods.
We are starting a new project to better understand our resident Roe Deer population and its characteristics. We will be using regular transects walks, anecdotal sightings recording and remote movement operated cameras to try and record the total number of deer, map out where their territories are and look for trends in their behaviour. We hope that a better understanding of the population will help us to find solutions to the damage they can cause.
In addition, we will be creating exclusions zones where we do not allow deer grazing so that shrub layer understory layers of the woodland can develop. These exclusions zones will include 6 areas of woodland with a 10-meter perimeter as well as a larger area of the reserve to the south of the second wind turbine where we hope to complete exclude deer from 3.2 hectares of scrub and wetland habitat.
The deer exclusion zones have been in place for some time now and we will be able to fully assess their impact in Spring 2024. We have now started trialling another method to try to protect some of our brambles and shrub layer within the woodlands. This has involved spraying patches close to the deer exclusion zones with a deer repellent, these patches are marked with a numbered post. The repellent is a natural product which is sprayed as an annual application in late autumn or early winter. It is a completely harmless taste and smell repellent based on emulsified sheep fat and is very widely used in forestry operations. We will be able to assess the effectiveness of this next Spring for future applications over slightly larger areas, without the need for fencing.
When the deer are out in our meadows happily grazing on grass, they are leaving the woodland alone so that young trees and bramble stand a chance. They will only graze out in the open if they feel safe, so we will continue to enforce the rules of the reserve which create that security – insisting that all dogs are kept on leads and that all visitors keep to our trails.