For my novel, http://www.tidalarchsaga.com/ !

Harpies, a small pissant race, live a short life of 20 years or so. They do not seem to harbor any interest for written language, or history. Family and social groups are easily forgotten. Sirens, however embody most of the things that harpies are not.

Sirens are the result of a physiological and psychological change that takes place in a harpy. It can happen at any age. One of the key characteristics is that they grow much larger than a harpy, and become (as some describe it) enlightened. They are able to conjure powerful storms, and a few other choice arcane power through words, such as Persuasion. They harbor intellectual prowess unknown to their harpy counterparts.

Every siren is a harpy, but not every harpy will become a siren. It is usually the result of a harpy finding a “Focus”. This Focus is usually a passion, such as a call to duty. For example, some become one to become a matriarch or patriarch to protect a flock, some, who may become deeply devoted to a particular mate, may incur the change through love (if the feeling is mutual it can happen to all members of the party, but more often it is one sided). Harpies, are more or less unclear on how to achieve the Siren change, and … surprisingly, not many care. Such are the foot loose ways of the species.

Sirens have become a faded tradition. When one does occasionally show up, it is usually on accident. A siren can quickly become lonely, as the psychological change from live-in-the-present harpy to an intellectual-siren is steep and, unfortunately in modern times isolating.