On an Ucayali river tributary used to live a modest married couple that had a daughter and two sons. Blanca (white) which was the girl’s name would always wear a white dress and was very dutiful, reason why her mother loved her very much. Plus, she had the ability to eat any kind of fish with a lot of ease no matter how many bones they may have.
Her siblings hated her so much that agreed between them, with the least bit of remorse, to find a warlock so that they could turn her into a bird.
Indeed, the warlock, taking advantage of the dark night, turned the girl into a beautiful white heron, just like the color of her dress and doomed her to live in the lake and river shores, feeding herself only with fish.
The chama natives of the Ucayali region have a lot of faith in that legend, because when a white heron flies over their huts singing its characteristic sound: cau cau cau, they immediately make their children swallow their saliva so that they won’t choke when eating fish.
It is said that this is why our natives have great ease in eating fish.
Source: Peruvian myths, legends and tales (Jose Maria Arguedas)