Yeah, moo. The scale is different on the bouzouki. Tuning is not part of the definition as there are many tunings. The closest thing to a standard would be GDAD, or maybe ADAD. Pat Broaders, who studied with Donal Lunny for a time, and who is currently playing with bohola (SEE this band if you get a chance, they are brilliant!), tunes his dordan (bouzouki on steroids ;->) CGCG. I have never seen the point in tuning them GDAE as then you are just playing an octave mando, with a slightly different scale length.

All the best,

Mick