What is a legend? Why is this poem called a legend?

A legend is a traditional story which is regarded as historical. This poem is called legend because of its tale being told to everyone by the Northland people. They narrate it curiously as it is a story to learn a lesson from, where a priest called Saint Peter cursed the old lady for her extremely selfish behavior and she turned into a woodpecker, and she would have to make her own home and find her own food by boring all day into the woods as punishment for making the priest angry by her extremely selfish act.