According to oral tradition, a bird prophesied the defeat of Benin's army to King Esigie (early 16th century) during the war against the Igala. Esigie shot the bird, defeated the Igala army and captured their king, Attah of Idah, who became a vassal of Benin. As a reminder of this false prophecy and of Benin's victory over the Igala, Esigie ordered the casting of bars with bird figures, which are sounded at the annual Ugie Oro ceremony. The bird of divination can also be found on relief panels or as a small ivory carving, and the species of bird cannot be precisely determined; it could be an ibis, an osprey or a cattle egret.