Hola! La expresión entera es "fueron felices y comieron perdices". Es una frase que se utiliza al final de los cuentos para decir que la felicidad de los protagonistas fue para siempre y nunca tuvieron problemas para comer o vivir. Por eso comen perdices, pero podría haber sido "y comieron cerdos" o "y comieron pavos" Espero que esto te ayude!

Thank you for your answer.I understand it very well.

Literally, it means "吃鹧鸪" but this phrase is usually used at the end of Fairytales as an ending line, similar to the English phrase: "they lived happily ever after". Why "perdices"? I guess this animal was chosen because 1) it rhymes with "felices" 2) at that time, it was an expensive dish that only rich people could afford, which suggests that they never had any problem