Deer numbers have exploded over the last couple of decades; with no apex predators to control their numbers, and modern farming practices improving habit and providing abundant feed. This has resulted in numbers becoming a strain not only for farmers, but also the deer themselves.
Disease is more prevalent in high density populations, as indeed are ticks and other parasites. This presents further issues for humans, as tick numbers increase due to the weight of deer, so to does the risk of lyme disease in humans and dog walkers face an escalating battle to keep canine friends tick free.
Perhaps the most significant downside in the increased number of deer is the commensurate increase in road traffic accidents, unfortunately resulting every year in human fatalities.
The current estimate is that deer numbers are at their highest in a 1000 years, a number that is simply unsustainable in our modern landscape. The government has recognised the impact this is having on our ancient woodlands in particular, and have included stringent deer control measures in main of the Countryside Stewardship Schemes.
The damage caused by deer varies from species to species. Deer can be categorised as either being predominantly grazers (eating grass and cereals) or browsers (eating young shoots, leaves, buds and bark).
Fallow Deer are widespread across the UK. They are a medium/large deer that can be found in large herds. They are predominantly grazers. As a result they can be a serious agricultural pest. Even a small group can do significant damage to cereal crops, and if undisturbed they will return night after night. While they can be seen out during the day, they are most active in late evening and overnight, using the cover of darkness to travel sometime significant distances to find the best food source.
During the day they tend to seek out the protection of woodland; as mentioned, the majority of their feeding is overnight, but they nevertheless feed throughout the day and forest fauna can suffer as a result.
Due to their relatively large size, heavy herding, and widespread distribution, Fallow Deer are perhaps the most frequent cause of serious road traffic accidents involving deer. A fallow buck is a large animal and can do serious damage; sadly there are human fatalities every year, particularly in high density hotspots such as Ashdown Forest.
Roe Deer are the most widespread species across the UK. They are small/medium in stature, and are predominantly solitary, although they are often seen in small family groups. They are relatively active during the day.
Being browsers roe can have a serious detrimental impact on woodland fauna. They are also agricultural pests where certain crops are grown, for example rape seed, trees, fruit canes, vineyards, and high value crops such as peas and kale. Market gardens in particular can be greatly impacted by overly heavy roe populations.
Muntjac Deer are increasingly widespread, thanks to a very rapid expansion over the last decade. They breed incredibly quickly, having no breeding season they produce more than one faun a year. They can now be found across much of England and Wales.
They are small in stature, and while predominantly solitary they have overlapping ranges. Extremely heavy densities are therefore very common.
Being browsers, like roe they can have a serious detrimental impact on flora and fauna. Although given the high densities that build up this is more pronounced than with roe. Muntjac can have a devastating impact on woodlands including decimating bluebells and other plants that are synonymous with traditional UK woodland. The Woodlands Trust have advised heavy culling of this invasive species, as it has an outsized impact in depleting biodiversity and rare flora.
They are also agricultural pests where certain crops are grown, as with roe they target trees, fruit canes, vineyards, and high value crops such as peas and kale.
Red Deer are less widespread in the south of the UK, but are found in relatively good numbers in pockets across the south of England and Wales.
They are the largest deer, with southern lowland animals particularly weighty. They herd in significant numbers. While they can often be seen during the day, in areas of high human density they can be very illusive; feeding predominantly at night. Like Fallow they are mainly grazers, and due to their size, and appetite, they can do significant damage to crops.
Sika Deer are also found in pockets across the south of England and Wales.
They are a medium/large herding deer. Like fallow and red deer, they are mainly grazers, and can do significant damage to crops. Like Fallow they also can cause serious damage to natural diversity through daytime browsing in woodlands. Another issue is interbreeding between the non-native sika deer and native red.
Chinese Water Deer are found across a limited range in East Anglia and the Midlands.
They are a small unusual deer. Unlike all the other UK species they happily live in open farmland if woodland margins aren't available, resting up in the middle of fields in broad daylight.
They are grazers and can cause damage to agricultural crops. Although they are not heavy herding so the impact is less than fallow, red or sika. As there range slowly increases, they are increasingly involved in road traffic accidents.