It's a very odd term "natural born" - what's it supposed to exclude? Apart arguably from Caaesarian births and so forth, which I rather assume aren't what it's about, how can any birth be other than "natural".

If they've put "native born" it'd be clear what was intended, though there'd be room for the kind of arguments in this thread. But "native born" - what on earth (or Mars) is that supposed to mean? Was it a drafting error maybe?