When it matures, the Red-crowned Crane is snow white with a patch of red skin on its head. This patch of skin becomes bright red when the crane becomes angry or excited. This species is the heaviest crane, typically 7.7–10 kg. In the spring and summer, the Red-crowned Crane breeds in Siberia and occasionally in northeastern Mongolia (i.e., Mongol Daguur Strictly Protected Area). Normally the crane lays 2 eggs, with only one surviving.