Mountain hares have a very wide, virtually circumpolar distribution extending throughout the tundra regions of Russia, northern Europe, Greenland and Iceland, with the closely related Arctic hare (Lepus articus) in Canada and Alaska. In the Old World their habitat extends southward throughout the boreal zone to the fringes of agricultural land or open grassland. In North America the Arctic hare is restricted by the boreal forest, which is inhabited by the snowshoe hare (Lepus americanus). This worldwide pattern of restriction by both habitat and other species of hare explains the distribution of the mountain hare within Britain.
After the introduction of the brown hare to England in Roman times, mountain hares became restricted to upland regions where they were able to hold their own, feeding on heather and other moorland plants, while the brown hares fed on lowland grasses and agricultural crops. By the early 19th century mountain hares were found only in the Scottish Highlands. Towards the middle and end of the 19th century - accompanying the development of grouse shooting and the management of heather for grouse - some landowners released mountain hares across the remaining British uplands. Many of these re-introduced populations have died out, leaving the large core population in the Scottish Highlands, a well established population in the Southern Uplands and a small one in the Peak District, while that in northern Wales has probably died out in the last two decades. The most recent estimate suggests that there are approximately 350,000 hares across this range.
As recent GWCT research shows, this is a relatively high density of hares compared to mountain hare populations anywhere else in Europe. As well as having affected the distribution of mountain hares through historical introductions, upland game management still affects their abundance as mountain hares seem to do best in areas managed for red grouse. Indeed it is probably the intensive fox control combined with rotational burning that benefits grouse and hares. However, where grouse suffer from tick and the tick-borne louping-ill virus, hares can sustain high levels of these parasites and help perpetuate the disease. As there is no alternative form of treatment, in these cases hare numbers may need to be temporarily reduced to suppress the disease.
On some grouse moors, hare shooting is a popular sport and provides additional income, supports keeper employment and moorland management. However, such sporting bags and other culls may be substantial and it is important to demonstrate that modern practices are sustainable and in line with good management. This should be a research and subsequently conservation objective as it is a requirement under the European Habitats Directive.