Why does a bird have a gizzard?

A busy bird is a snack eater, for he rarely can take time for a full meal. yJhatts more, he needs a constant supply of energy from his food, for he always is on the go. A digestive system like ours would not meet his needs. Each snack goes to the gizzard where it is quickly mashed to pulp and put to work. The gizzard is a little fist of hard muscle which does some of the work done by our stomachs.

When mashing up tough food, the little gizzard fist needs help. It uses grit and sharp stones to cut up the crumbs and crusts. When a chicken wallows a small pebble, it goes into the gizzard along with the food, As the muscular fist squeezes and pummels, the stone will help to mash the food into pulp which can be digested.