Harpyfolk are a sort of fairfolk, meaning their origin was a result of magical influence rather than natural selection. Harpies don't know whether their ancestor was human or perhaps a bird before she was magically altered, but they don't consider themselves part of humanity and prefer to remain in isolated communities of their own kind.
Harpyfolk are generally all female, reproducing asexually when exposed to specific and intentional conditions (a certain diet and frequent exposure to warm+dark environments. Usually nest helpers are the ones wanting to have eggs)
Because of that, they're always genetic clones of their mother, though there's the occasional case of a mutation resulting in a male hatching (smaller and more colorful).
Even though there isn't a lot of genetic diversity amongst harpies, there is plenty of variation in appearance and behavior. During their developmental years, harpies are strongly influenced by various environmental factors, which trigger the expressions of different traits. Once that developmental phase is past and a harpy's appearance settles, they're considered an adult.
Without hands practical for writing, harpies are very reliant on oral culture. They spend a lot of time singing and telling stories. They do have a simple landmark scratching writing system to help warn and guide around resources and dangers.
Mate pairs aren't really a thing, but it's not uncommon for them to take on life partners. Different social roles are taken in the absence of distinct sexes which sometimes influence language (pronouns for social role/job as opposed to gender)
Their limited interactions with humans were variable but ended very sourly. They have a habit of attacking human trespassers which gives them a reputation for being violent and feral.
