During the time taken for saddling up and getting started, the ostrich herd had moved eastward and now was out of sight, even through the glasses. Ali led for the place where they had been seen, and as they rode gave the boys a little homily on the great birds they hoped soon to stalk. Ostriches are found throughout Africa, except in the central and coastal regions of great forests. Especially do they haunt the waste places and deserts, where stunted bushes furnish sufficient food for their needs. Their hardihood and fleetness makes life possible where other animals could not exist. Even sand and pebbles apparently can be digested by them, and it is a fact that the domesticated ostriches of farms and zoos have been known to swallow glass, barbed wire, bright-colored bits of metal, bed springs, and other similar objects. Unfit for food, these great birds are valued because of their beautiful feathers, which can be plucked at certain seasons of the year without harm to them. For this reason, the Arabs of northern Africa and the colonists of South Africa for long have domesticated ostriches. In South Africa alone, latest estimates were that the number of domestic ostriches was between 800,000 and 900,000. Ostrich-raising also has been introduced into California and Arizona with varying success. One of the chief worries of the ostrich raiser is proper incubation of the eggs, which take at least forty days to hatch and more frequently a full seven weeks. In their wild state, the ostriches lay their nests of great eggs—ivory white in color among the birds of the Sahara, mottled among those of Basutoland and South Africa—on the top of a sand dune, whence they can see in all directions and guard against surprise. The male takes his turn with the female in sitting on the nest. Jackals, drawn by the chance of obtaining some of these eggs, almost invariably haunt the ostriches. When an unguarded nest is found, the jackal pushes a big egg up the sand slope with his nose and then lets it roll down into the nest. Coming into contact with another egg, usually both become cracked. Then the jackal sucks the contents. There is so little on the desert to feed the jackal that the dangers he runs from the attack of an infuriated ostrich are braved in order to obtain such a succulent feast. Observers have reported seeing a jackal pursued by an ostrich and running in zigzag fashion for his burrow. If he fails to reach it in time, one swipe of the ostrich’s leg tosses him yards away and disembowels him.