Six species of deer exist in the wild in the UK: red and roe deer are the only native species; though fallow deer are now normally considered part of our natural heritage, having been introduced in the 11th Century and possibly before. Sika, muntjac, and Chinese water deer were all introduced within the past 150 years. These six species differ in their geographic distribution, abundance, population growth rate, behaviour, and impacts.
It is widely accepted by government agencies, NGOs, and academics that deer are more abundant and widespread now than at any time in the past 1000 years. Deer populations have increased rapidly in recent decades due to several factors, including:
- Milder winters;
- Changes to agriculture such as the planting of winter crops;
- Increased woodland cover;
- Escapes and releases from parks and farms; and
- Greater connectivity between green spaces in urban areas
At present, there may be as many as 2 million deer in the UK. However, accurate assessment of deer numbers is very difficult because deer are secretive animals and are free to roam the landscape. Evidence for increasing deer numbers is found in the expansion of their geographic range and the increase in deer impacts. Deer occurrence is not restricted to rural areas, and they are increasingly found in suburban and urban areas.
With a lack of natural predators in the UK, the role of human control becomes more important. An estimated 350,000 deer are culled each year. Road accidents are the second biggest cause of deer mortality. Despite this, deer are continuing to expand in range and have increased impacts, and it appears that current mortality rates are not high enough to prevent the rise in deer populations.