The Kakapo is an interesting example of a flightless bird that fills the niche normally taken by mammals.
You are right about the fauna. For example, the New Zealand Pigeon is the only surviving bird species that can spread the seeds of some plants, and this species is in trouble especially in some locations.
The fact that you only saw 9 native birds (not counting sea birds) is a sad testimony of the status of native bird population.
Some tourist information advertises the "silent New Zealand forests". How sad?
