This is probably an old theory, but I haven’t seen it anywhere, so I thought I’d throw this out there:
Magnetism plays a big part in the story of the island. People say Walt is “special” right? What if what makes him special is that something about him makes him able to affect magnetic fields?
Check this out:
It’s a page that talks about how birds use magnetic orientation to navigate.
It Walt can affect magnetic fields, wouldn’t it throw off nearby birds? He’s probably doing it by accident, which would explain the dead birds we’ve seen on the show and the webisodes.