A little too deer?

Describing deer as vermin is anathema to most – but, says John Bryan, it may not be as far off the mark as you think

Discussing deer as vermin might not be as outlandish as you might think. To begin with, only two of the six deer species we have in the UK today are native: the roe and red. The roe is questionable as the truly indigenous population had been virtually wiped out by 1800. The current stock is mostly descended from continental specimens re-introduced after that near extinction and topped up by successive re-introductions throughout the Victorian era.

Until the 1960s most deer, and particularly roe, were treated as vermin, with much of the control achieved by driving to shotguns. The 1963 Deer Act was the first to lay down specific conditions on the killing of deer, notably minimum calibre requirements and an outlawing of the use of shotguns on deer except under very limited and specific circumstances, and even then only with 12-bore or larger and AAA shot. Large shot like that has excellent velocity retention but is known for poor patterning from most guns, limiting effective range to around 20 yards.

Bluebell woods are particularly vulnerable to ‘predation’ from muntjac

In the half-century that has followed, the attitude to deer has changed enormously. In the eyes of much of the public, deer are the shy, harmless and iconic animals of cartoons and children’s stories. At the other end of the scale the rise in popularity of stalking and natural, free-range meat has meant that in some locations deer have come to be regarded as a sporting and financial asset, outweighing the damage that they cause.

So why is control necessary? As with most ‘vermin’ the need for management stems from two things: population size and conflict with human interests. Deer numbers are now estimated to be greater than at any time since the last Ice Age. According a scientific assessment, published in the Journal of Wildlife Management in 2013, Britain’s deer population is at risk of causing serious and sustained damage to wild flowers and birds. Scientists reported that the huge deer numbers have created a ‘hyper-herbivory’ that is destroying the nation’s woodlands and its wildlife.

Essentially deer are grazers but particularly in woodland environments. They will browse seedlings up to as large as ‘thicket stage’, fray bark over a metre high and decimate what is known as the ‘herb layer’.

Just one example of the damage deer can cause. Photo: John Athayde

Coupled with the spread of human habitation, this population growth has lead to inevitable conflict along the margins. Some species of deer, especially roe and muntjac have even made the transition to built up areas being spotted in parks, large gardens and roadside verges. Earlier research in 2009 estimated that more than 74,000 deer may be involved in vehicle collisions each year in Britain. This is clearly a major animal welfare issue but is a significant risk to humans as well. The study estimated that between 10 and 20 people a year are killed and 700 injured through accidents involving deer – not just direct collisions but also secondary accidents through swerving to avoid deer on the road. The cost of damage to vehicles was estimated to be at least £17m.

Of all the deer species, the Reeves’s muntjac (Muntiacus reevesii) is the one most likely to be labelled as a pest. Small, adaptive, ferocious and an indiscriminate feeder, the muntjac has comfortably made the transition from isolated woods into nurseries, plantations and gardens. The muntjac was originally introduced to Woburn by the Duke of Bedford. Few other introductions have spread as fast as the muntjac. This is attributable to several factors, notably the rapid breeding rate, with does coming back into season within 48 hours of giving birth. This means they have a fawn every seven months or so. Added to their affinity for the densest cover and adaptability as regards habitat, this has greatly aided their spread. Muntjac are a primitive species of deer and have a simpler digestive tract, so they can capitalise on food sources other deer cannot – the impact of muntjac on a bluebell wood can be devastating. Although muntjac are territorial they still seem to be able to live in very high densities where habitat is suitable.

Bucks are equipped with enlarged canine teeth, forming tusks with a sharp point and a cutting back edge, which evolved for territorial disputes between bucks but are just as well suited to defence against dogs and can injure people if the animal were cornered.

Roe deer: An iconic species but can still cause major problems with browsing and fraying. Photo: Pascal Vuylsteker

Roe deer (Capreolus capreolus) have also become a more common sight, and their naturally high breeding rate has led to their rapid spread into new semi-urban territories. Roe exhibit a fascinating breeding strategy known as embryonic diapause. Rather than rutting in the autumn and struggling to regain lost condition to survive the winter months, roe rut in July/August. This would normally lead to kids being born in late winter, when there is a shortage of food. Roe get round this by rutting early, beginning the development of the foetus, then stopping the development until later in the year. This leads to a total gestation of some 9-10 months, with kids born in May/June, and twins being normal, with a high proportion of these making it to adulthood. Taller than the muntjac, they can reach further and jump higher but cannot hide in the undergrowth quite so well.

We all enjoy the idea of deer roaming wild in the English countryside, and to catch a glimpse of them still a little bit special. To preserve the balance of nature and keep what is so extraordinary about our ecology, it is time to recognise that things are perhaps a little too deer…

Muntjac: Rapid population growth makes for a severe management challenge. Photo: Joe Pell

Non-lethal control:

For any deer overpopulation problem the best option is to establish a proper stalking and deer management programme. This will not only control overall numbers but will allow selective culling of weaker deer, will generate revenue or at least goodwill and will get good quality free-range meat safely and responsibly into the food chain. Where this is not an option the British Deer Society advises a number of non-lethal methods of control.

Protecting trees

Protective tubes can be applied around stems to protect them from deer, but these are only of benefit to broadleaved trees. The tubes must be at least 1.5 metres tall and must be rigidly staked to the ground to prevent deer knocking them over. Alternatively, netting guards can be used for conifers and shrubs.

Excluding deer

Fences must be at least 1.5 metres tall with mesh no greater than 10cm by 10cm to keep out fallow, roe and muntjac. Fences must also be staked to the ground or partially buried to prevent deer from pushing underneath. An exit, such as a self-closing gate or jump, should also be provided to aid the escape of any deer managing to gain access. Grids or gates should also be placed where driveways enter the garden. Electric fencing can be effective against larger deer species but raises safety questions in urban areas.

Deer will only try to jump a fence if they are unable to pass through or under it. Digging a ditch on the far side of the fence will deter them from doing so. On top of this, deer will be less inclined to jump over a barrier if they cannot see what is on the other side.

Scaring deer

Sonic sirens, flashing units and streamers may work for a short time – but deer will soon become used to their presence and ignore them.

The eco-friendly approach

A good way to protect plants while maintaining a healthy, diverse garden is to provide natural, alternative browse for the deer. This can be achieved simply by allowing brambles, rosebay willowherb, rowan (mountain ash), dandelion, campion, hoary cinquefoil, knotweed, sweet lupin, redleg, ribwort and yarrow to grow within the garden. Deer will then preferentially eat these and may avoid your vegetables, crops or favourite plants.