Sanctuary Mountain Maungatautari, is a protected natural area in Waikato Region, New Zealand where the biodiversity of 3,400 ha of forest is being restored.

[1] The sanctuary, surrounded by a pest-exclusion fence, is a good example of an ecological island, which allows the original natural ecosystems to recover by minimising the impact of introduced flora and fauna.

Maungatautari, as an eroded volcano was chosen as a suitable site for a major ecological project for a number of reasons, including the diversity of its terrain, the relative integrity of natural areas in spite of some human engineered changes, the commitment of surrounding communities, and the feasibility of fence-construction given surrounding developed terrain.

[citation needed] In December 2004, eleven endangered Hochstetter's frogs were found living on Maungatautari in a rocky region.

There had already been discussions about potentially reintroducing the Hochstetter's frog to the preserve, and the rare discovery of the small population in an environment being prepared to protect them excites the scientific community.

[2] Because poisons and trapping, traditional methods of pest control, have limited success and seldom last long, the creators of the plan decided to enclose the 34 square kilometres of bush with a 47 km pest-exclusion fence to create an ecological island.

[citation needed] In November 2003, the Trust constructed two exclosures, at the north and south of Maungatautari, totalling 1.1 square kilometres.

The Trust used these areas to demonstrate the fence's feasibility and to test pest removal methods, which were launched in September 2004.

In 2007 the sole remaining pest species was mice, and poison was dropped a third time, in September that year, to eradicate them.

[3] One of the greater challenges facing the designers of the Xcluder fence adopted for the purpose was addressing entry at streams.

Since water levels fluctuate and a fence needed to address both debris and fish migration, the Xcluder was outfitted with an electronic surveillance system to alert the Trust if a watergate fails to properly close.

[citation needed] In July 2006, a viewing tower was constructed near a northern rata grove in the southern exclosure.