The Forest Citadel

Heathly rata-kamahi

Healthy rata-kamahi forest cloaks the outriders of the main divide at Otira, Arthur's Pass National Park. The Department of Conservation has dug in at Otira in a bid to save this increasingly rare forest mix from possums. Aerial 1080 operations every few years are supported by ground operations using bait stations.

Native birds at Otira in October are singing a loud song - that 1080 poison operations over close to 40 years have controlled possums and benefited native species. Ian Gill, a community relations officer at the Department of Conservation's West Coast Conservancy, has the tapes to prove it.

"Come to this place in October and it's a cacophony of birdsong - tui, bellbird, grey warblers, robins, and tomtits," Gill says.

He has been making bird recordings at Otira every month for more than a year and sometimes brings doubters - people who claim that forests are silent after 1080 operations - along for a listen. "It takes the discussion out of the armchair and into the forest. For many people, it's the first time they've actually sat down and consciously listened to the birds around them."

Ian Gill

The 9,000ha of rata-kamahi forest around the tiny hamlet of Otira, west of Arthur's Pass, is one of few remaining healthy tracts of West Coast forest. Groves of mountain cedar and totara reach up to alpine herbfields on the main divide. Otira residents still see great spotted kiwi (roroa) scampering across the state highway. Kaka, kereru and kararea (falcon) are common sights.

Elsewhere on the West Coast, possums have munched rata and kamahi, their favourite food, to oblivion. Oddly, possums will hit on a single tree over many nights or weeks, ignoring neighbours till the tree dies. The forest canopy is littered with gaunt grey skeletons. In the Whitcombe valley, the destruction is so complete that the rata-kamahi canopy has gone altogether.

Once that happens, the forest is changed forever. Only possum left-overs remain: the species they cannot or don't want to eat. In the Kokatahi valley, horopito (pepperwood), broadleaf and quintinia have replaced rata, kamahi and totara.

This fate has been avoided at Otira, where DOC has set up poison bait stations around homes, farms and watercourses, and conducted aerial 1080 operations, roughly every five years.

Rata-kamahi

If 1080 decimated native wildlife, Otira ought to be the place to prove it, Gill says. Despite the abundant birdlife there, however, some people still insist that forests are silent after 1080 operations.

"There could be any number of reasons why people aren't hearing the birdsong around them but sometimes it's plain mischief making."

The timing of 1080 operations is one reason for the silent forest illusion, he says. "Often 1080 drops are mounted around May or June, when possums are hungry and more likely to eat the baits. Another month or so and we're into the hardest time of the year for birds. There's not much to eat and they don't have a lot of energy."

"There is a silence after autumn 1080 operations but not because the birds have been poisoned. Right observation, wrong deduction."

Kamahi flowers

Gill peers intently into the forest canopy, holding aloft an unfeasibly large microphone. The birds are few and subdued today. A persistent, if monotonous, bellbird. A single, distant robin, and the zit-zit of a rifleman. Then there are the immigrants; a blackbird, a chaffinch.

It's the dead of winter at Otira, in three degrees of frost.

Most birds have headed down to warmer climes in search of food. In spring the steep slopes flanking the gorge will turn red again and birds will return from winter feeding grounds to a nectary of brilliant, white kamahi flowers.

One small oasis where things are still as they should be.

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