"Avian" came up as a term, though I tend to associate that with anthropomorphic bird people in general.
In classical mythology there were only 3, who were all transformed women, rather than being a specific species. But that's been played with quite a bit since then, given that it's all made up anyways.
According to the Forgotten Realms/D&D wiki, a male harpy is still called a harpy, but have the basic appearance of being female (meaning that they have breasts) thus giving one the misconception that there are no males. And a couple of other fantasy authors have written male harpies just to flout existing representations and the larger connotations that often come with those. Which is what I was doing with the title here, as the main influence was really more of a demon anyways.
There's a lot of overlap in the various story accounts. Gorgons (3 sisters), Harpies (also 3 sisters), and Sirens (I think there were around 5?, usually unrelated) all have stories connecting them to some form of transformation as divine punishment but with different reasons.
Thinking about it, I suppose "The Siren" would've worked just as well for a title......