[bcdarwin]

I am not claiming that the possibility is excluded, just that it is not demonstrated here.

> In mammals, this is what guides birds to migrate. It's far more than that and the earth undergoes these field changes every interval with profound impact on life on earth.

> You and I are all made out of Earth and the things we eat and breathe are all Earth itself. There's just no way that we can brush off this phenomena with pedantry.

I agree that biology is profound, but pseudoscientific generalities like this confuse rather than clarify. [Likely typo: birds are not mammals.]