IMPORTANCE OF BIRD GRAVEL
Nature did not supply your Canary with teeth to help grind his food. The food goes directly to the crop where it is mixed with digestive juices and softened. Thence it passes to the gizzard, where with the aid of gravel previously swallowed, it is “ground up” for assimilation. The gizzard is a small thick pouch with very tough, muscular walls which rub against each other at great pressure. When gravel is present, this action grinds the food into a soft, easily digested mass. Therefore it is essential that your canary have free access to a plentiful supply of gravel of the right kind and size. Gravel composed of limestone or magnesia should not be used, because it is readily dissolved by the bird’s digestive juices. Beach sand may have harmful impurities and is usually worn and rounded.
Gravel should be hard, sharp rather than round, and not affected by digestive juices. French’s Bird Gravel is crushed silica sandstone quartz and meets these requirements perfectly. It is thoroughly washed, carefully screened to a uniform size, and then sterilized by heat. When sprinkled on the floor of the cage, it helps keep the bird’s feet in condition by wearing off the scales and dirt, and it is a distinct aid in keeping the cage floor clean and dry.