Nestled in a gully on the southern side of Sanctuary Mountain Maungatautari stands the Tautari wetland.

The specialised ecosystem was established by the Maungatautari Ecological Island Trust in 2009, after the land was gifted from the Tauroa family who owned the adjacent farm.

After having been meticulously cultivated since then, the wetland now closely resembles what it would have looked like before humans arrived in the Waikato.

Gary Farrow Sanctuary Mountain Maungatautari volunteer Graham Parker is a passionate educator on conservation efforts in the Tautari wetland.

The threatened, nationally vulnerable takahē are one of the key beneficiaries of the enclosed wetland.

Sanctuary volunteer Graham Parker took me on a walk to see how the trust is working to try ensure a future for the species.

Not long at all after we entered the enclosure, we saw one of the adults from a distance, foraging in the grass.

Maungatautari Ecological Island One of the breeding takahe living in the Tautari wetland at Sanctuary Mountain Maungatautari.

Just as quickly, though, it had made its way into the thick foliage off to the side of the path. So the search continued to get a closer look.

"Takahē are a flightless bird which was, historically, over much of New Zealand," Graham said.

It resembles the common pukeko, with the addition of a prominent green sheen to its feathers.

It's also a lot more bigger, with a particularly large beak and head.

The takahē was originally thought to have become extinct in the first half of the 20th century.

"But in 1948, Dr Geoffrey Orbell found a pair of takahē in the remote Murchison Mountains in Fiordland, and from those small beginnings and some careful management, we now have 347 takahē known to be alive today."

The Tautari wetland is home to a breeding pair of takahē, along with their large chick, which is still in its juvenile uniform black feathers.

The sanctuary provides them, along with another breeding pair and their chick on the other side of the maunga, with plenty of safe places where they can feed, rest and raise their young.

Every now and then we would hear some deep, punchy thuds that seemed to come out of nowhere. The sound felt like it was at the very lowest range of human hearing.

It resembled the calls I have heard made by large flightless ostriches, emu or cassowary, and I was surprised and impressed to learn that the noise was being made by the takahē.

Many offshore islands became essential sanctuaries to ensure the species' survival, including Maud Island in Marlborough Sounds, Kapiti and Mana near Wellington, and Tiritiri Matangi and Mototapu in the Hauraki Gulf, as well as fenced mainland sanctuaries such as Tawharanui and Maungatautari.

"A young chick from here, along with a couple of other chicks its age, was re-released back into the Murchison Mountains where they had originally come from 70 years ago," Graham said.

At the end of our circuit through the wetland, having seen many other species, the takahē proudly made their appearance.

It was humbling to see them living their lives in an environment the likes of which would probably not exist in the Waikato were it not for the hard work of the passionate people at Sanctuary Mountain.