You wont have much problem with the parry's mate, they are like flying rats, bloody everywhere!
You will definitely have more birds in the south than most parts of the North. Best to get some good local knowledge, go to this site http://www.fishnhunt.co.nz
This is a good place to start. The guys are more than happy to help out and provide info for a fellow hunter, you may be surprised with the offer of a shoot or two as well. most north island seasons end around 30th June so you may need to factor that in depending on where you want to shoot. feel free to PM me if you need any other info.
Just because you haven't done something, doesn't mean its not worth trying.