The Pogrom of the Magical

Population Migration / Travel

As the magic in the world left it isolated among all the planes, the people began to fear those who bore resemblance to the magical beings of the past and many took to forcing those they feared as far away as possible.

Many magic items gave the ability to fly but as the magic from these items disappeared, the people became envious and fearful of those races that could still fly - with many claiming that they had made a deal with some evil being that allowed them to keep their magical powers, although whether this pact was actually made is unknown.
The races that suffered the most in this pogrom were the Aarakocra, and the Kenku, due to their resemblance to birds.
These races, seeing that they were no longer welcome, retreated from the mainland to separate far off islands where, while it is known that they are still there, it is not known how well off they are, how many there are, etc.