The legend of the stork originated in Scandinavia. It is said that, at the time when babies used to be born at home, mothers told their children that babies had been brought by the stork justifying the sudden appearance of a new member in the family. To explain the mother's rest after giving birth, it was said that, before leaving, the stork had pecked her leg.
The stork was chosen as a symbol due to its docile and protective characteristic, which pays special attention and affection to sick or older birds. The ancient Romans created a law encouraging children to take care of the elderly, called Lex Ciconaria (Law of the Stork).
In addition to this reason, there is the fact that storks usually make their nest beside the chimneys of houses and always return to the same place, to lay eggs and take care of the young. The mix of generosity and loyalty to the nest created a perfect symbol. The legend spread around the world in the 19th century, through the tales of the Danish writer Hans Christian Andersen.
Curiosities - Brazil School
Source: Brazil School - https://brasilescola.uol.com.br/curiosidades/origem-da-lenda-da-cegonha.htm