Fantastic Crests of the Middle Ages :
The crane as a symbol is more commonly seen in oriental cultures. But the common crane, and its cousin the stork are also to be found in Europe. These migrating birds return every spring and so they symbolize this season’s joy and exuberance in new life. The Greeks and the Romans also used these birds to symbolize love because of their flamboyant courtship displays.
More serious, biblical culture sees in the common crane a symbol of alertness and mutual aid.
According to the “Bestiary Medieval,” common cranes, take turns keeping watch over their eggs and hatchlings during the night. To help keep their alertness sharp during these night watches the crane holds a pebble in its raised leg. It is in this attitude that the common crane is sometimes represented on shields and especially on flags; which is called " common crane holding its alertness "
But in crests, they are represented most often by the head and the wings only (this sometimes makes it difficult to differentiate it from a heron).
Raoul de Gaucourt used a crane's head as see in nature, along with two white wings with at gold crown at the base (coat-of-arms : Ermine two barbels Gules).