LOFTY mountains that pierce the clouds and reach to dizzying heights may appear to us humans as coldly majestic, lonely, even forbidding. Yet to a great variety of wildlife they constitute home. Some of these creatures would never think of descending to lower altitudes. And to see them in a zoo, even if they could long survive such a humiliating experience, one could gain no realistic idea of their way of life among peaks and chasms.Some of these creatures are not very familiar to us, while the names of others have almost become household words. For example, have you heard of the nyala, with its spiral horns measuring up to forty-four inches in length? It was discovered in 1908 at 9,000 feet in the mountains of South Abyssinia. On the other hand, who has not heard of the chinchilla? The mountain variety lives at an altitude of 17,000 feet.Up at those heights, too, there are birds that soar high and make their nests in unapproachable places. There are birds of great variety, such as hawks, eagles, the black duck, slender-billed chestnut-winged starlings and a host of others