The Amazingly Incredible Bird Whistle! Our whistles are meticulously hand crafted from the finest clay and contain absolutely zero hazardous materials. Always environmentally safe and sane! The secret is in the clay. Unlike bird whistles made from wood or plastic that deplete our natural resources, our whistles have an unmistakable resonance only realized with the use of clay. Simply add water, a small measure at a time until you achieve the perfect pitch.