Moose call. A small horn of wound and stitched bark.
The Ojibwa, Canada's largest indigenous people, use birch bark megaphones as moose lures. The shape of the cone is designed to amplify the voice in such a way that the hunter can imitate the soft whining call of the cow to attract bulls during the mating season. Birch bark is a versatile material, and other uses for it in Ojibwa culture include canoes and sacred scrolls.