Tuesday, May 7, 2013

Wild Horses of The Namib Desert

Fighting for a life in freedom...

They hold an irresistible fascination: the Wild Horses of the Namib in south-western Namibia. For centuries their origin was shrouded in mystery. Their habitat, the barren plains around Garub on the eastern fringe of the Namib Desert, is no paradise; nevertheless they have managed to adapt to the harsh conditions. Their forebears, once in the service of man, gained freedom for themselves: a life in the vastness of the Namib, away from human civilization, according to the rules of their own horse society. Perhaps this is the reason for the fascination of thousands of visitors every year. Plans for moving the herd to farms have been discarded by now: it has been decided that also in future the horses’ place is in Namib Naukluft Park.
With the support of the Ministry for the Environment the numbers and behaviour of the Wild Horses have been scientifically documented since December 1993. Numbers fluctuate according to the quantity and quality of available grazing. After the drought in 1992 and the resulting drive to catch the horses, their number increased from 110 (1993) to 149 (1997). It dropped to 89 during the drought of 1998/99, but had risen to 147 again by April 2005. In order to maintain the genetic diversity the number should not drop below 100. According to estimates the area can support a maximum of 160 horses.

The adaptation of the Namib’s Wild Horses to their habitat is not genetically evident. Reports about extraordinary resilience may safely be relegated to the realm of myth as well: many of the animals which were caught during the drought of 1992 and taken to farms succumbed to horse-sickness and other ailments. Adaptation can rather be seen in their behaviour: patterns of feeding and drinking, resting and playing match available grazing and prevailing temperatures.
 During dry conditions, when grazing becomes scarce, the horses basically have to ‘work’ for the quantity of nutrients they need. Then they cover vast distances, feed wherever possible and rarely play. Visits to the drinking trough are put off for as long as possible. In contrast to domestic horses, thirst causes them very little stress. During the hot summer months (November to March) they come to drink at average intervals of 30 hours, while during the cool winter months (May to September) intervals average as much as 72 hours.

When good rains have brought forth fresh grass and numerous flowers the Wild Horses adopt a ‘leisure mode’: they feed at night, and as there is no need to cover vast distances to get their fill they remain close to the drinking trough for longer periods of time. Up to 80 percent of the herd gathers there. They drink every day, regardless of temperatures, and play and rest a lot. Their leisure time offers the best opportunity, of course, for watching them and taking pictures...
Apart from grass the Wild Horses also eat their own dry dung. This does not mean that they are desperate - it is natural behaviour, also seen in domestic horses if they have access to dry dung. The dung of the Wild Horses contains almost three times more fat (1.99 percent) than the area’s dry grass (Stipagrostis obtusa – 0.7 percent) and almost twice as much protein (6.1 instead of 3.1 percent).

Since horses are no ruminants, eating dung is the only way to absorb nutrients which have been excreted undigested and in concentrated form. The dung, however, is merely a supplement; less than 1 kg of dung is eaten for every 7 kg of grass. Thus there is no danger of harmful substances accumulating in the horse’s system.

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