| About Reindeer Husbandry - What biological characteristics specific to the reindeer? |
| Tuesday, 15 September 2009 17:13 |
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What biological characteristics specific to the reindeer? Reindeer are well adapted to the Arctic climate and have the capacity to cope with long, cold winters. Their abilities are due to their physiological structure and unique characteristics. Reindeer have the capacity to absorb so much nutrition from summer grazing that they can survive a tough winter, when food is scarce. But this presupposes that the reindeer succeed in accessing nutritious grazing throughout the summer. It is therefore important that reindeer are not are disrupted by unnecessary activities during summer grazing period. Reindeer have a highly developed sense of smell which helps them to find food in winter. In winter lichen is their main diet but they also eat other plants under the snow pack as well as lichens that hangs from trees. During summer they graze different types of grasses, herbs and leaves and have a great fondness for mushrooms that grow in the late summer and early autumn. Reindeer is a ruminant and has a unique ability to absorb lichens, which are highly nutritious. Another advantage of the reindeer is that it has a good ability to adapt its behavioural patterns to pasture availability. If it is able, it takes only the best parts of the pasture. However, a ruminant will have difficulties to survive if pastures are suddenly altered because the micro-organisms in the stomach need a certain amount of time to switch to new pastures. If a reindeer starves, it may have a negative affect on its ability to digest food even if it gets enough food after a period of starvation. In some areas reindeer are fed artificially (with grass or specially developed reindeer pellets) for various reasons, to prevent starvation. The weight of a reindeer varies with age and access to nutrients. In the autumn, the live weight of cows is usually 60 to 100 kilos and 90 to 180 kilos for bulls and bullocks. A newborn calf weighs 4-6 kg and already by the autumn it weighs between 30-50 kg. Bulls and bullocks in woodland areas weigh more than mountain reindeer as summer pastures in the woodlands are more favourable than the mountain pastures. The thick heat-conserving winter coat of the reindeer is shed in summer and begins to grow again in August. The coat of a fully grown reindeer consists of outer bristles and an underfur. The outer bristles are thick and straight, and they form numerous air pockets which provide insulation and prevent body heat from escaping. The underfur creates a thick pile for the winter coat and prevents the movement of air inside the coat. However, the cold does not present a problem for a healthy reindeer, which can survive in temperatures below -50ºC without increasing its production of heat energy. The legs of the reindeer are also able to withstand the cold well, and the blood circulation in them is improved by specialized system of veins and arteries and by the presence of oleic acid in the marrow of the lower legs. Oleic acid has a melting point of +15ºC and acts a kind of anti-freeze, keeping the legs unfrozen even in very cold temperatures. Both male and female reindeer have antlers and they make new antlers annually. Calves also make antlers and they begin to grow already during their first weeks of life, and by the autumn they usually have 10 20-cm-long almost unbranched tines. The antlers are important in competition between the male animals, and they serve as identifiers and status symbols during the rutting season in autumn. The antlers also have a beneficial effect for the females, especially when they are pregnant, in the difficult snow conditions of winter. Bulls drop their antlers in the winter, and the non-pregnant females drop theirs early in the spring. Only the calves and the gravid females have antlers at the critical time in April and May. The latter animals now enjoy the highest status, and they can ensure sufficient nourishment for themselves and their fast-growing foetuses. The pregnant cows usually only drop their antlers after calving and begin growing new ones in the good feeding conditions of early summer. |