SierraScape February - March 2007
Back to Table of Contents

by Ken Schechtman, PhD

The following article contains the authors' reflections following a recent visit to New Zealand.

The South Island of New Zealand contains a confluence of diversity that defines as magnificent a landscape as our planet can provide. The close proximity of fjords, glaciers, mountains, forests, rivers, and ocean presents a breathtaking panorama that evokes spiritual musings even among the most secular non-believer. The seas provide frequent sightings of whales, dolphins, seals, and penguins. And millennia of isolation have produced unique plants and birds that, for many, are the most magnificent wonder of all.

But as always when humans intervene, hubris takes center stage and environmental degradation becomes a constant, almost predictable companion. In New Zealand, the diminished ecosystems are characterized by the best of intentions gone awry; by careless would-be corrections that exacerbated the manmade folly they sought lamely to counteract. The best illustration may be the plight of Kiwi birdlife.

The story began 160 million years ago when the entire southern hemisphere and the Indian subcontinent formed a single massive land mass called Gondwana. During this late Jurassic period, Gondwana began breaking up, a process that took 80 million years to complete and that culminated when modern New Zealand separated from Antarctica.

New Zealand is among the most geographically isolated places on Earth. It is 1000 miles southeast of the Australian landmass and hundreds of miles from the nearest of its far smaller island neighbors. To the south, there is ocean, ice, and Antarctica. As with Madagascar, the Galapagos, and other remote island redoubts, evolution combined with millennia of solitude have produced unique flora and fauna that provide unequaled opportunities for the botanist, the bird watcher, and the ordinary awe-inspired traveler.

Nurtured by an abundant rainfall that exceeds 300 annual inches in the fjord known as Milford Sound, thousands of waterfalls cascade down the densely forested walls of the surrounding mountainsides. Each step through the lush and barely penetrable rainforests presents a plant or a tree that exists nowhere else on Earth. There are three large families of birds and dozens of species that live only in New Zealand. And one look at a takahe, a kiwi, or a weka is a reminder of the uniqueness of this extraordinary land.

But as in so many other places, the native forests have been reduced (by about 80%), the glaciers are receding, and non-native plants and animals create repeated threats to the fragile ecosystems. And most poignant of all in a country whose national symbol and nickname is its most exotic bird of all, the birds are threatened, are often endangered and, all too frequently, are extinct.

The separation of New Zealand from Antarctica occurred prior to the Cenozoic age of mammals. It produced an ecosystem that was devoid of land-based predators for tens of millions of years. Aside from the now extinct Haast's eagle (whose 9 foot wingspan was the world's largest among eagles) and some smaller predatory birds, New Zealand's pre-human birdlife had nothing to fear.

One evolutionary result was a distinctive avian population that had few defenses. Many of the birds became flightless. They had no fear of native wildlife and, by extension, of humans and the mammals they introduced. Some were less than protective of their eggs. One can see it today in the species that have survived the human onslaught. For example:

If you use a stick to expose the worms that are a mainstay of its diet, the Stewart Island robin will sup eagerly on the meal, not caring that you are inches away. The rare yellow-eyed penguin nests comfortably in the forest, unconcerned about the distance from its haven in the sea. Near the city of Dunedin, the southern royal albatross with its majestic 10 foot wingspan lays eggs on an exposed hillside, and there is evolution-induced complacency regarding the vulnerability of its young. And everywhere, as you look eagerly for the exotic remnants of the once vast colonies of flightless birds, you are gratified by how easily you can approach. But you are heartsick at the implications of this simple and trusting behavior.

Aside from Antarctica, New Zealand was the world's last large landmass to be visited by humans, with Maori ancestors first arriving in the 13th century. Beginning about 5500 years ago, seafaring residents of what is now Taiwan began colonizing the South Pacific Islands. They went first to the Philippines and, after 2000 years of island hopping, they arrived in central Polynesia and what are today the French owned Society Islands and the independent nation of Tonga. It took 2000 more years to float their way south to New Zealand.

When Polynesians arrived about 800 years ago, they found a plush New Zealand landscape and an endlessly diverse supply of easy dining in the flightless birds. Most are now extinct. The mainstays of the Maori diet were the several species of moa, a flightless ratite that at 10 feet included the tallest (though not the heaviest) bird species ever to exist. There were an estimated 158,000 moa when humans arrived. Within 200 years, there were none.

But the carnage had only begun. Starting in the latter half of the 18th century, European colonization rapidly accelerated a long and ongoing path towards deforestation, habitat loss, and extinction. While the Maori had brought some domesticated mammals, European colonization meant an exponential increase in these non-native species. Rats arrived as stowaways; deer, cattle, and sheep became a dietary staple; rabbits were imported for the sport of hunting them; both rabbits and possums provided coats; and cats and dogs were pets for the new colonists.

Beyond the obvious deforestation that was a predictable legacy of grazing animals and expanding cropland, there were unintended consequences at every turn. The rabbits did what rabbits do, and their vast numbers began destroying crops. The possums, which today number in the many millions, dined happily on the eggs of tree nesting birds. Stoats, a weasel-like predator, were brought in intentionally to hunt the overabundant rabbits, but even more than the plentiful rat population, they had a fondness for the eggs of the flightless birds that nest on the ground. And all too often, the cats became wild.

One disheartening illustration of the latter followed the abandonment of an early 19th century settlement on Stewart Island, a southern outpost below the main South Island. Today, Stewart Island is a nature and bird preserve with less than 300 human residents who inhabit 2% of its several hundred square miles of national park. But the original settlers left pet cats behind, and their numerous wild ancestors are now open season for hunting by New Zealanders who love cats, but whose first obligation is to preserve the dwindling birds.

Today, nearly every remaining flightless bird in New Zealand is either threatened or endangered and has a tenuous future in the wild. The unique South Island takahe, the world's largest member of the rail family, was hunted to what was thought to be extinction by 1900. But in 1948, a small colony was found in a remote area of the World Heritage Sight that is Fjordland National Park. There are now perhaps 200 survivors that are threatened not only by stoats and rats, but also, by the introduced wild deer that compete with the takahe for the same food. The North Island takahe is extinct. The beautiful kakapo, the world's heaviest and only flightless parrot, numbers little more than 100. More than 50 bird species that lived in New Zealand when humans arrived will never again be seen. Another 50 are listed as endangered, threatened, or vulnerable.

Even the precious kiwi, the exotic national symbol and the nickname for New Zealand, has been dramatically reduced because its eggs have a 5% survival rate in the wild, because the nurturing father must leave the egg to eat, because the kiwi has a distinct odor that is a dead giveaway to stoats and rats, because evolution provided young kiwis with little protection against predators that are recent and unanticipated guests.

Efforts to reverse these processes are ongoing. Non-native predators are routinely hunted and poisoned. Remaining native forests and the habitats they provide are mostly free of logging and roads. Many of the small surrounding islands are bird preserves where predators have been largely eliminated and where bird proof traps are ubiquitous. And at $2000 each, kiwi and other endangered bird eggs are rescued from their predators, incubated, inoculated, and nurtured. And when the young birds are ready, they are returned hopefully to their native habitat.

Some of these efforts will succeed, and some of the remaining birds may succumb to the coming decades. But this astonishingly beautiful land is a reminder to us all. We are blessed with only one planet and only one grand ecosystem. We can save it. Or we can do what we have done for so many, many years.

The author is indebted to Ron Cometti, a New Zealand naturalist, author and artist for reading and commenting on this article.