Making The Lord Of The Rings in New Zealand has given the country huge cinematic exposure.

In the films New Zealand's forests gave virtuoso performances as the woods of Middle-earth. Lothlorien, the Golden Wood of the Elves, was played by a native beech forest.

Like the woods of Middle-earth, the forests of New Zealand are not immune from destructive forces. The trees are under attack from a predator just as voracious as Saruman's orcs.

But is it really as Treebeard prophesised - does anyone care for the woods anymore?

Birds of a Feather

Large birds, like the extinct Moa, are the natural carers of New Zealand's forests. They are needed to eat and disperse the seeds of trees with large fruit. But there is now only one surviving bird species which is big enough to do the job - the Kereru, New Zealand's native wood pigeon, also known as the Kukupa.

At least one New Zealander wanted to save the woods. Eight days before she died of cancer in 1997 environmentalist Jacqui Barrington gave an interview in the forest outside her home for a film she hoped would eventually be made.

Jacqui was concerned about the cultural harvest of Kereru by the Maori, the first people of New Zealand. She wanted them to recognise that it is no longer sustainable. The six week period of development from egg to independent bird means the Kereru are very vulnerable to attack. And they only lay a single egg, making survival even more precarious.

Kevin Prime is a Maori farmer from Northland. It was his helping hand which Jacqui found for the Kereru.

Kevin's tribe, Ngati Hine, established a rahui, or ban, on the harvesting of Kereru. They invited other tribes to join them in a nationwide rahui.

Motatau is the forest cared for by Kevin Prime. Maintaining such forests is vital to conserving New Zealand's unique biodiversity. And the lynch pin of that biodiversity is the Kereru.

In the Taranaki region, named after its mountain, the Department of Conservation is investigating the seasonal habitats, foods and nesting requirements of the Kereru.

The study extends to farmland, residential areas and urban parks, where Kereru are found in both native trees and imported exotics. The wildlife corridors are made up of both native forest and plantings by landowners.

The Real Orcs

Orcs are an invented Middle-earth species. But there is a real creature which is ravaging both the forests and the bird life of New Zealand.

The possum was introduced from Australia in the 19th century. Its numbers are now estimated to have grown to 70 million. It thrives on the native trees and damages them to the point that there are dead trees throughout the forest.

New Zealanders like to say that the only good possum is a dead possum. Spring culls are a source of pride.

Kevin Prime teamed up with the government science agency Landcare Research to get infra-red video evidence of the possum peril. One Kereru, disturbed at night by a possum, flees its nest, leaving the possum to dine on its egg.

The infra-red footage from Landcare Research, recording one second every minute, shows that many possums in Motatau forest come to feast on muesli put out for them in bait stations.

When the muesli was replaced by "1080" poison, the ground is littered with possum carcasses by the next morning. It certainly dropped the numbers of possums quickly. But the poison was not enough to keep new possums from entering the forest. It was only after intensive trapping around one tree that a single Kereru chick survived to leave its nest.

By keeping the pest numbers down to a low level, seven Kereru were protected enough to reach to the fledgling stage of growing up and flying away.

So in saving Motatau forest, Kevin proved that the Kereru can only perform its vital seed dispersing role if the possum is stopped in its predatory tracks. He believes that creating core areas of protection can work, especially once they are expanded and begin to overlap.

Hope for the Kereru

Stephanie May is an ecologist studying the Kereru. She explains that, as the only disperser of large fruit species, the bird is vitally important for the regeneration of the forest. And it's not only the trees that depend on the integral role of the birds, but entire ecosystems. As Stephanie says of the Kereru: "If it goes, hundreds of species go with it".

One way to maintain the forests and its native wood pigeon is to establish what are termed 'mainland islands' - like Wenderholm. Free of possums, this regional park is a haven for Kereru. They owe their lives to the 1080 fed to possums in bait stations.

In many other forests the poison is applied by aerial drops. The practice is controversial as it can affect other species. Some New Zealanders believe there has to be a better way than this.

The Maori would not traditionally have viewed the possum as a pest. Every part of the animal would have been used for food or materials - from fur and teeth, to heart and brains. Kevin believes the species would have been sustainably managed by reducing high numbers through possum feasts. When animal numbers got too low, a rahui ban could be put on their use.

In modern times, controlling the possum population takes on new forms. Snowy Peak is a company which has recognised the power of fashion to turn a pest into profit. They have put protecting the environment at the core of their branding.

Company founder Peri Drysdale scored a publicity coup giving President Clinton a possum jersey when he was in New Zealand. In the public mind possums are no longer just worthless road-kill, but a high value product with a ready supply of the raw material.

Possumdown was the pioneer of eco-fur brands in the early 1990s. Now it exports around the world from a factory in Auckland. It's been called the new cashmere - one boutique designer calls it "Fur With Ethics". Possum fur turns a problem into a comfortable solution - a feel good product if ever there was one.