Tristan took me on a full day habitats tour. I was the only one who signed up for the day (he never takes more than his 7 passenger van can hold), so it was a private tour. Tristan is exceptionally knowledgeable about the plants and animals of the area and is obviously passionate about New Zealand's environment. We had a beautiful and tasty picnic overlooking the water within a nature reserve and saw and heard many birds.
This tour is not for people who aren't able to hike a bit, but it's completely worth it!