Does anyone know what my pet says in Chinese?

The Chinese words you post is “食腐鸟”。
食：means eat
腐：means rotten
鸟：means bird
A vulture is a 食腐鸟，becaus vultures eat the flesh of dead.
I don’t think your bird ( parrot, crested myna, and the like) say 食腐鸟, because it lacks sense.
May be your bird says “吃不了” or “受不了”, which means I’m stuffed or unbearable respectively, and their Pinyins are “chī bù le” and “shòu bù le” respectively. Their pronunciations are more or less similar to 食腐鸟；though if pronounce it correctly, their pronunciations are not the same.