Arctic hare (Lepus timidus) - Snow-white through the winter
The Arctic hare, also called Mountain hare or Blue hare, can be found in America as well as in Europe and Asia. It inhabits the tundra and forest regions of the far north. In Europe there are also populations in Southern Scandinavia, Scotland and Ireland. The Alps are inhabited by the Arctic hare too and in Asia its distribution range extends to the Central Asian steppes. The worldwide stocks seem to be stable, but the populations of the Alps are quite endangered. The Arctic hare reaches a length of 70 cm and a weight of 3 kg, which is a little less than the measurements of its well-known relative, the European hare.
All species of hares (genus Lepus) are quite similar to each other. All of them have large, lateral located eyes. This position of the eyes is typical for animals, which have to be able to escape very quickly. Hares are capable of seeing their surroundings within an angle of 360 degrees and detecting a possible danger very soon. But their eyes are not suited for seeing three-dimensionally and they are not very good at estimating distances. Since hares are vegetarians this is no real handicap, because their food is "growing into their mouths" more or less. Hares are a very sought-after prey for many predators and they are not very able to put up a fight. So their only chance to survive is to escape very quickly and if they have to, they are very fast and agile, reaching speeds of about 80 km/h and tricking their pursuers by darting from side to side. There are not a lot of predators, which are able to follow an escaping hare. But first of all hares try to avoid such situations by behaving as inconspicuous as possible, hiding among bushes and stones most of the time. The colour of their fur is a perfect camouflage, since it mimics the colour of the surroundings, which can be found in their habitat - and here we have the first obvious difference between the Arctic hare and the European hare: During the summer the two species look quite similar; their fur is speckled brownish grey, often with reddish brown components and brighter as well as darker areas. But before winter begins, Arctic hares change their fur; they turn snow-white and are hardly visible in the snow-covered scenery. How long the winter fur is worn depends on the geographical distribution of the hare population. Arctic hares inhabiting extreme arctic regions wear their "white dress" even during summer, whereas Irish populations don't exchange their brown fur for a white one at all.
There are also differences between the Arctic hare and the European hare concerning their social behaviours. European hares are mainly solitary animals and group structures occur just in cases of high population densities. But the Arctic hare can be described as quite social. Especially in the harsh arctic regions there are often accumulations of several hundred hares. These groups are anonymous and the individuals don't recognize each other. They have the effect of increasing the security of each member of the accumulation. But also group structures of smaller size with a well defined hierarchy are known. Those structures require individual recognition. It is common that such groups build walls of snow to protect themselves from the weather. This is another contrast to the European hare, which doesn't create any kind of burrows.
An Arctic doe is pregnant twice or three times a year. Litter size varies between one and five pups. In contrast to newborn rabbits, young hares are well developed. They have a complete fur, are able to see, hear and run around. But during the first days of their lives they hide in dips, dug by their mother. The doe normally visits her young just once per day to give them the opportunity to suckle. Such a long period between two visits is possible, since the doe's milk is very nutritious: 23% fat content is common. Like many species inhabiting regions of extreme climate, Arctic hares tend to give birth to as many young as possible and minimize their investment in the individual young. In regular intervals there are fluctuations concerning the population density. First it increases due to the high reproduction rate until an overconsumption of the habitat's resources occurs. The condition of the animals aggravates, they are starving or serve as an easy prey for predators. At last the population breaks down and just a few animals survive. These animals are the basis for the next mass reproduction, which will start, when the stocks of forage plants have recovered again. The development of the predators also fluctuates and follows the one of the hares with a certain delay. Such a cycle has a duration of about ten years in the Arctic hare.
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