Arriving at breeding sites at the beginning of April, white-naped cranes locate their mates from previous years and participate in a long and complicated set of coordinated calls, in amongst other crane species doing the same thing. The female initiates the display, in which both sexes extend their necks and lift their heads; the males utter one call for every two from the female (5). Once the pair bonds have been re-established they move to the nesting sites, just as the swamps start to thaw. They build a nest of dried sedges and grass in open wetlands, amongst dense vegetation. One or two eggs are laid between mid April and mid May, and during the 30 day incubation the pair will vigorously defend the territory around the nest. Once the chicks have hatched in June or early July, the parents are less vigilant about defence, spending more time feeding the chicks. They fledge after 70 to 75 days and reach sexual maturity in their third or fourth year (9).
At the breeding grounds white-naped cranes feed on insects, small vertebrates (such as frogs and toads), and the seeds, roots and tubers of sedges and other wetland plants. At the wintering grounds they take tubers, roots and fruits, and will also feed on rice grains, or the cereal seeds provided at an artificial feeding station in Izumi, Japan (9). As in all cranes species, the white-naped crane is often seen ‘dancing’: flapping the wings, tossing grass and sticks, jumping, running and bowing. As well as being involved in courtship, this is thought to reduce aggression and relieve tension (5).