The habit which ostriches have of sticking their heads into the sand, leaving the body exposed to danger, has often been mentioned in books and used as an illustration of what a fool will do. But when one comes to study the ostrich in its home on the desert the habit does not seem at all foolish. Indeed, it is a wise provision of nature for the safety of the bird in a region where hiding places are scarce. When a brood of young ostriches is warned by their guardian they instantly fade out of sight. Gauchos told me that they had surprised broods of more than a score, of which they were able to find no more than three or four, and yet those birds had no more shelter for hiding than was afforded by a dozen or so of small bushes. Squatting motionless, with his head in the sand, the ostrich is so near in color like the sand and the scant herbage that grows there that even experienced hunters fail to see him. His body looks like a gray desert bush--so much like it that a man may look at without recognizing it. When looking for young ostriches the gauchos examine every bush within many rods of the spot where a brood disappears, and so find very often that what seemed to be a bush was wholly or in part a young ostrich. With its head up, of course, the ostrich would be at once detected. With its head in the sand it often escapes even the keen-eyed fox, the gauchos say. Ostriches readily learn the habits of their persecutors. When Patagonia was first discovered by white men the aborigines were afoot, and the ostriches, being hunted by men afoot, were accustomed to flee at the sight of a man afoot. The Spaniards introduced horses on the pampas and at first the ostriches were not greatly frightened by a man riding. Very soon, however, they found the mounted man dangerous. For some hundreds of years only mounted men pursued the ostriches, and they at last got to a point where they did not fear a man on foot. Then came a great flood of emigrants to Buenos Ayres--chiefly Englishmen and Italians, both classes everywhere the avowed and open enemies of innocent bird life. These took guns to slay the ostrich, and straightway a man afoot once more became an object of terror, while the smell of powder smoke, it is said, will set the pampa birds running away when the gun is at a distance of two miles. Further than that, a ranch owner is found here and there who will not permit ostrich hunting on his grounds. The birds quickly learn where they are safe and gather from surrounding districts in great bands, leaving the hunted grounds bare. And what is more remarkable still, the very birds that will flee for their lives when started by a man on the hunted grounds will show not the least concern at the approach of a man when they are on safe ground.