I've seen a number of kiwi on Stewart Island, where they tend to come out during the day, which is quite unusual.  Unfortunately, I've not seen a kiwi in Fiordlands but sure have heard quite a few.  They are nocturnal and secretive and when they don't want to be found, you won't find them.  I've had one calling less than ten meters away but it was the middle of the night in the bush and it remained hidden.  

They were calling all night long and there were dozens of footprints on the track, so they are out there. As you can see, these are not small tracks.