Island sanctuaries: Tiritiri Matangi, Zealandia and Ulva

Much of New Zealand's rarest birdlife survives because people removed the predators from a patch of land and kept them out. Some of those places are islands; others are mainland valleys ringed by pest-proof fences. Many welcome visitors, and they offer the best chance most of us will ever have to watch hihi (stitchbird), tīeke (saddleback) and takahē going about their day.

This note looks at three very different sanctuaries: an island in the Hauraki Gulf, a fenced valley in the capital, and a forested island off Rakiura Stewart Island. For a wider picture, Sanctuaries of New Zealand runs a national network of sanctuary projects and is a good place to find others near you.

Tiritiri Matangi: the open sanctuary

Tiritiri Matangi is a small island of about 2.2 square kilometres, 3.4 km off the tip of the Whangaparāoa Peninsula and about 30 km north-east of central Auckland. Years of farming left it mostly grassland. From 1984 volunteers began replanting, and hundreds of thousands of native trees later the island is green again. Kiore (Pacific rats) were eradicated in 1993, and a long line of rare birds has been moved there since.

Today it's an open sanctuary run by the Department of Conservation (DOC) with the Supporters of Tiritiri Matangi, a volunteer group. Visitors can walk the tracks freely, and the birding can be extraordinary.

What to look for: takahē grazing on the lawns near the lighthouse; kōkako singing from the canopy, especially early; hihi and korimako (bellbird) at the water and feeding stations; tīeke calling noisily from the forest floor; pōpokotea (whitehead) flocks; and kākāriki (parakeets). Kororā (little penguins) also nest around the coast, so watch your step near the shore.

Getting there: A public ferry runs on set days, and it often sells out from November to April. Private boats can land at set spots, and charter operators need a pest-free warrant. Overnight stays are possible in the bunkhouse, but there is no camping. Check DOC's Tiritiri Matangi page and the ferry operator's own site before you plan.

Tip: Walk slowly up through the gullies rather than straight up the main track. The shaded streams with water troughs are where hihi and korimako come to drink and bathe.

Zealandia: a fenced valley in the city

Zealandia (Te Māra a Tāne) shows that you don't need an island to make a sanctuary. It protects about 225 hectares of regenerating forest in a valley just minutes from central Wellington, enclosed by an 8.6 km pest-exclusion fence finished in 1999. Once the fence was complete, introduced mammals inside it were removed.

Since then, birds that had been gone from the region for a century or more have been reintroduced: little spotted kiwi in 2000, tīeke and kākā (forest parrot) in 2002, hihi in 2005, and takahē in 2011. Tuatara from Stephens Island were released in 2005, too.

The effect has spread well beyond the fence. Kākā now range across Wellington's green belt, and residents of many suburbs see tūī far more often than they did a few decades ago. It's one of the clearest examples of a "halo" effect from a single sanctuary.

What to look for: kākā near the feeders and along the lake edges; takahē on the grassy flats; hihi and tīeke in the valley forest; and pāpango (New Zealand scaup) on the lakes. Night tours, when offered, can turn up little spotted kiwi and tuatara.

Tip: Visit early in the day. As the morning warms up, the birds retreat further into the bush.

Ulva Island: forest birds at the bottom of the country

Ulva Island (Te Wharawhara) lies in Paterson Inlet on Rakiura Stewart Island. It's about 267 hectares, almost all within Rakiura National Park, and it's a short water-taxi ride from Golden Bay wharf. There are no roads or accommodation, just a network of walking tracks through tall, mossy podocarp forest.

Ulva has been free of rats for long periods since an eradication in the 1990s, but it's close to the main island and rats keep swimming over. DOC has run several responses in recent years. Whether the island is currently declared rodent-free or not, it is intensively monitored, and your biosecurity checks matter here more than almost anywhere.

What to look for: the South Island tīeke; mohua (yellowhead) in the canopy; the Stewart Island robin (toutouwai), which often comes close to watch you; titipounamu (rifleman); kākāriki; and kākā overhead. Some visitors see a Stewart Island kiwi (tokoeka) foraging in daylight, which happens here more than on the mainland. Hoiho (yellow-eyed penguin) also breed on the island: keep well away from any penguin you meet.

Tip: Stand quietly at a track junction for ten minutes. On Ulva the birds often come to you.

Biosecurity: your part of the deal

These sanctuaries exist only because they are free of predators, and every visitor is a possible risk. Before you board a ferry or water taxi:

• Check bags, pockets and food containers for mice, rats, insects and seeds. Pack food in sealed containers.
• Clean soil and seeds off boots, tent pegs and walking poles.
• Never bring pets, plants, or animals of any kind.
• On arrival, use any boot-wash stations and follow the staff's directions.

Once ashore, stay on tracks, don't feed the birds (sanctuaries manage their own feeders), and take all rubbish away with you. If you see a rat or mouse on a predator-free island, tell the sanctuary staff or DOC straight away. Early reports are how incursions get caught.

Choosing your sanctuary

If you can only manage one, choose by where you'll be. Tiritiri Matangi is the best all-round introduction to North Island rarities. Zealandia is the easiest, most accessible option and a great choice with young children. Ulva Island is the wildest of the three, with South Island forest birds you won't find on the other two.

Whichever you choose, give it time. A sanctuary rewards patience more than any other kind of birding in this country.