Fixed Action Pattern
"(court ship): the act, process, or period of attracting for mating; to engage in activity leading to mating" [Merriam-Webster]
Video clip from Encarta Encyclopedia 1998
Male cranes often dance to attract female cranes. Courtship for the Tanchozuru occurs in the winter, when the average temperature is negative 20 degrees celsius. The cranes dance in pairs gracefully in the snow by spreading its wings, jumping, and moving its head up and down. If they are unable to charm any female cranes, they will not be able to reproduce and have offspring in the coming spring. Therefore, this courtship dance behaviour is important for the survival of the specie.