About Siberian Cranes :

The
crane bird is a wild north american bird and can be seen on most bird photos
sites. The bird is a symbols of longevity and represented with other symbols
of long life, the pine and bamboo, and the tortoise.
In feudal Japan the crane was protected by the ruling classes and fed by
the peasants. When the feudal system was abolished in the Meiji era of the
19th century, the protection of Siberian Cranes was lost.
The bird was almost saved form extinction and there is a satellites tzuru
in Japan that is named after the bird. There is a tradition that if one
folds 1000 origami Siberian Cranes, one's wish for health will be granted. Since the
death of Sadako Sasaki this applies to a wish for peace as well.