Tea on Mou Waho Island, in the middle of Lake Wanaka. We had paused at an idyllic spot in the Southern Alps of New Zealand's South Island. As we admired the vast glacial lake, surrounded by snow-capped mountains, an uninvited guest strolled into view.
Unperturbed by our presence, the buff weka examined the Thermos, the mugs, the tea bags and the biscuits. Eventually, realising that it would not be sharing our spread, it wandered nonchalantly back into the bushes.
Fearlessness and inquisitiveness are the characteristics that spelled doom for New Zealand's flightless birds when rats, stoats, rabbits and possums were introduced. The buff weka has been extinct on the mainland for decades. But thanks to predator-free sanctuaries, such as Mou Waho, it's rebuilding its numbers, although it remains endangered.
Chris Riley has played a part in the bird's revival. His company, Eco Wanaka Adventures, runs half-day tours to the nature reserve. Each time he visits Mou Waho, which has two shimmering lakes of its own, he plants a native sapling. Chris also keeps an eye open for stoats; these wily creatures, lured by the aroma of weka, occasionally swim across, braving nearly a mile of deep water.
The wild South Island of New Zealand offers adventure-seekers everything from remote trekking to whale-watching. Within an area the same size as England and Wales, you can float over tranquil meadows in a hot-air balloon, get up close to a glacier, enjoy the fruits of the southernmost wine-making region in the world, or visit the adventure capital of the world, Queenstown, which sits beside Lake Wakatipu in the shadow of the Remarkables range. Yet Wanaka, situated on the doorstep of Mount Aspiring National Park, is not unlike its bigger, brasher neighbour. As well as being a lakeside location with sensational mountain scenery, Wanaka offers all the outdoor activities associated with Queenstown: skiing, jet-boating, rafting, canyoning, kayaking, paragliding, rock climbing, mountain biking and fishing, but without the latter's commercialism.
Chris believes that serene Wanaka has learnt from Queenstown's mistakes. Most of the lake's perimeter is protected from development. So the unsullied view from the summit of Mou Waho, where a rare New Zealand falcon perches on a rocky outcrop, is unlikely to change.
There are great views from Aspiring Campervan Park, just outside Wanaka town. New Zealand prides itself on its campsites, or "holiday parks", many of which offer scenic settings and facilities including television lounges and well-equipped kitchens. Aspiring has a sauna and two indoor spa pools: a perfect remedy for aching limbs after a day's hiking.
Given the standard of such sites, and good roads with light traffic, many visitors hire a camper van to explore the South Island. New Zealand is relatively permissive about "freedom camping" outside designated areas, although some municipalities are clamping down. The Department of Conservation runs campgrounds in national parks, with basic facilities.
We flew into Wellington, collected our van and hopped on one of the regular ferries linking the North and South Islands. The last hour of the picturesque voyage to Picton is spent traversing the Tory Channel, part of the convoluted network of waterways, peninsulas and inlets that constitute the heavenly Marlborough Sounds. In Picton harbour, three dolphins materialised next to our boat, where they cavorted and frolicked like naughty puppies.
Among the many trips out of Picton, you can take a water taxi to the Portage Resort Hotel and eat locally caught snapper and salmon overlooking tranquil Kenepuru Sound. Kayaks can also be rented at Portage, which is an overnight stop on the four-day Queen Charlotte Track, one of New Zealand's best walking trails.
Nelson, west of Picton, is the sunniest spot in New Zealand, yet the west coast is one of the world's wettest places, with average annual rainfall of 270 inches. Travelling between the two, we discovered that camper vans can be a challenge on the South Island's twisty mountain roads. It's advisable to choose a compact vehicle, possibly forgoing a bathroom.
The highway bordering the west coast features wild, rugged scenery, including the amazing "Pancake Rocks", enormous limestone formations sculpted into horizontal stacks. Stay overnight in pretty Hokitika, which has craft shops selling local pounamu, or jade, and a driftwood-strewn beach.
The weather is wild and a savage storm a week before we arrived had effectively closed Fox Glacier, one of the chief lures of the West Coast. But we were lucky: Fox had just reopened. Our guided walk up the valley and on to the ice was a singular experience. We climbed through a rainforest of orchids and tree ferns, and ascended the ice with the help of crampons. The glacier resembled a field of egg whites whipped up to dirty peaks, with the sunlight revealing a spectrum of blue tones, together with myriad shapes and textures.
Notices warning climbers not to linger in "active landslide areas" were an ominous reminder of ever-present danger. We saw a massive boulder that had recently tumbled down, smashing an information sign. Our guide, Rodger, cast frequent glances up the slopes of the valley.
Overshadowing the glacier are New Zealand's two highest peaks, Aoraki (rising to 12,313 feet, and also known as Mount Cook), and Mount Tasman (11,473 feet). On a clear morning, both are reflected in nearby Lake Matheson. Milford Sound is the biggest attraction of the West Coast – indeed, in all of New Zealand – so your experience may be marred by crowds. So take a cruise on neighbouring Doubtful Sound, which is 10 times bigger and far less busy. It is a place of awesome natural beauty, where sheer, forested cliffs tumble down to glassy waters. When the boat's engines are off , the silence is overwhelming.
Near the shore, we saw seven dolphins, part of a resident pod of 60. On the rocky islets that dot the sound's entrance, fur seals lolled, while a solitary fiordland crested penguin waddled around.
The best of the South Island comes last, for at its southern extremity lies the wonderful, windswept Catlins Coast and, offshore, the little-known gem of Stewart Island. Despite a daily diet of jaw-dropping scenery up to this point, I was instantly besotted with both. The Catlins feels distinctly off the beaten track. Unsealed roads lead to tall cliffs, deserted beaches and bays frequented by dolphins, sea lions, fur and elephant seals, and endangered yellow-eyed penguins. You may see whales, and even albatross – but, if not, Dunedin's Otago Peninsula, 70 miles to the north, has the world's only mainland royal albatross colony.
The route ends near Bluff, the port from which the Stewart Island ferry departs. (Camper vans have to be left at the Bluff terminal.) The island is an unspoilt wilderness, with 150 miles of walking tracks, but only 17 miles of proper road, and is excellent birdwatching territory.
In the one township of Oban (population 380), blue penguins nest near the jetty, while large, noisy kaka – which are seldom seen in the wild – congregate in the garden of the excellent Stewart Island Lodge. The island is the likeliest place in New Zealand for you to spot the elusive kiwi. Even if you don't, you will almost certainly see other rare birds, including yellowheads and saddlebacks.
A plaque outside Oban states: "'I must go over to New Zealand some day' – Stewart Islander." After a few days in this extraordinary place, a visitor may well share those same sentiments.
Air New Zealand (0800 028 4149; airnz.co.uk) flies to Auckland from Heathrow via LA or Hong Kong, with connections to Wellington, Queenstown, Christchurch and the rest of the South Island. Return fares to Auckland are on sale until 6 Jan from £699; internal flights start at £90. To reduce the environmental impact, you can buy an "offset" through Abta's Reduce my Footprint initiative (020-7637 2444; reducemyfootprint.travel).
G etting around
Maui (00800 200 80 801; maui.co.nz) rents two-person camper vans from NZ$172 (£66) per day in January and February to NZ$75 (£29) per day from May-September. The ferry crossing (00 64 4 498 3302; interislander.co.nz) from Wellington to Picton starts at NZ$395 (£152) for two people, with a van. Stewart Island ferry (00 64 3 212 7660; stewartislandexperience.co.nz). Returns NZ$120 (£46) per person.
A powered camper van site costs about NZ$45 (£17) a night on the South Island.
Stewart Island Lodge, Halfmoon Bay (00 64 3 219 1085; stewartislandlodge.co.nz). Doubles start at NZ$390 (£150), room only.
Mou Waho Island tours with Eco Wanaka Adventures (00 64 3 443 2869; ecowanaka.co.nz) cost NZ$140 (£54).
Marlborough Sounds Adventure Company (00 64 3 573 6078; marlboroughsounds.co.nz) offers kayak tours for NZ$65 (£25) per person. Fox Glacier Guiding (00 64 3 751 0825; foxguides.co.nz) offers treks costing NZ$89 (£34).
Doubtful Sound day trips with Real Journeys (00 64 3 249 7416; realjourneys.co.nz) start at NZ$260 (£100).
newzealand.com; 00 64 9 914 4780.