I don't believe that we should have to register these drones, but at least in the U.S.A, owning a gun is a defined right where as owning and operating a drone is not.
Not to mention that at the time of the Second Amendment's writing gun technology was primarily limited to muzzle loaders. If you want to argue that modern cartridge loading guns get grandfathered into an "ownership right" implied by the Second Amendment, then lets argue that drone technology is also a new technology development that is equally likely to fit within some auspices of the right to bear arms (or the right to a free press in view of camera drones) and thus is equally a so-called "defined right".
The same way freedom of speech was written in before the advent of the internet.