Hit the road (munt)jac!
As you may be aware, the Silk Wood Community Planting Project (SWCPP) team at Westonbirt have been planting using tree guards, a practice designed to reduce the impacts of deer and other mammals on the vulnerable saplings – which would become a very tasty snack otherwise. The team have been testing several different tube materials, along with more traditional plastic guards, to see how they stand up to the rigours of time, weather and animals.
One of the materials on test was cardboard, which were used on some larger small-leaved limes at the very beginning of the project. These haven’t lasted quite as well as the lifespan needed from a tree guard (at least five years), with many degrading around the base of the tree, becoming redundant. Because of the size of these trees, being much larger than others, it was decided to see what impact this reduction in protection has on them, to see if re-guarding is indeed necessary.
The SWCPP team were recently joined by Westonbirt’s on-site Wildlife Ranger, Ross, for a trip around the project site inspecting the activity caused by the resident deer populations. As it turned out, many of these limes had indeed been damaged – but not through browsing. Looking at the base of the trees, where the guard had sagged or fallen off completely, most had obvious marks on the trunks. These took the form of rough scrapings, or deep gouge marks, a common sign of the smallest deer species on site – the Muntjac.
Muntjac are a small, stocky species of deer originally introduced to England from China at the start of the 20th Century. Following accidental and deliberate releases, feral populations have become well established in the south of England and are moving north year on year. It’s thought this invasive species will soon become the most populous deer in the UK, and we’ve seen plenty of muntjac activity on the wildlife cameras we’ve placed around the site.
Both the male and female muntjac are territorial, and they mark their boundaries using scent glands on the face. It’s this scent marking that Ross thinks is causing the damage to the trees – mainly by the males (bucks), who have small antlers and elongated canine teeth, or tusks, which are being used to rub against the trees. The tusks are most likely causing the pronounced parallel gouging we’ve also seen in some of the pre-existing hazel on-site, and the antlers causing the rougher markings on limes.
So, what about the trees? As the damage has been spotted early, the team doesn't think this will be enough to kill them, but they do want to prevent it getting worse. Any wound in a tree’s protective bark can cause abnormal growth, such as calluses or burrs, adds more stress thus reducing growth or establishment, and is an easy entry for pathogens and other tree pests to infect or damage the tree further. Therefore, they've decided to remove the remaining cardboard guards and replace them with a plastic mesh to prevent the deer from getting to them. This can be wrapped around the trees, which are too large for the alternative guards we’re currently testing.
All in all, this has been an interesting experiment and really highlights the need for effective deer control – be that management, fencing or tree guards for woodland planting sites. It also proves the need for protective tree tubes within the planting project. Thankfully, most of the other tube materials are holding up better than the cardboard, but the team will keep an eye on them to ensure the saplings get the best possible start in life.
Read our other blogs about the Silk Wood Community Planting Project here...
You can find out more about how Forestry England are managing deer at: Managing deer in the nation’s forests | Forestry England
