Wild About Utah

You may think of “the old grind” as your workweek, but from a dietary perspective, the old grind links your holiday turkey with dinosaurs. Before making gravy this Thanksgiving, find the densely muscular organ amid your turkey’s giblets. This is the turkey’s gizzard which preceded the living bird’s intestine. In its tough-walled gizzard, a bird mechanically breaks down hard or tough foodstuffs like we mammals use our molars. Reducing chunks to crumbs gives digestive enzymes the large surface areas needed to efficiently digest food.

Being toothless, birds must swallow most nuts, seeds, bugs and mollusks whole. In the gizzard, these items are churned, crushed and ground up, aided by ingested sand, grit or small stones called “gastroliths”. A turkey’s gizzard squeezes with twice the force of our own jaws. At 400 pounds per square inch, this force shatters acorns and even hickory nuts. The gizzard works like the ball mills used in mining, wherein heavy rotating iron drums loaded with steel balls pulverize rock ore. Like a gem tumbler, though, the gizzard eventually smooths and polishes its gastroliths. Having thus lost their utility, these stony gastroliths are regurgitated.

Gastroliths did not originate with birds, Continue reading “Bird Gizzards and the Old Grind”