Some notes on the difficulties of nature conservation in New Zealand and how a local community is rising to the challenge
by June Hilder with photos by Greg Hilder
Ferns along the Robin Valley Track
This article discusses why many of New Zealand’s ecosystems are in trouble and outlines an ambitious project to restore the ancient indigenous biodiversity of eastern Otago both within and beyond the confines of a designated eco sanctuary.
New Zealand's native biota is unique and fragile because when the land broke free and drifted away from Gondwanaland some 80 million years ago, it took with it a biological community which included amphibians, reptiles, birds, insects and many species of trees and other plants, but no browsing or predatory mammals (New Zealand Wildlife Service, 1985). New Zealand's birds and insects gradually adapted and occupied ecological niches which were filled by mammals elsewhere in the world; several bird species became flightless and ground dwelling (New Zealand Wildlife Service, 1985). The distinctive nature of the flora is demonstrated even today by the fact that around 80 percent of native plants are endemic (Cave & Paddison, 2002).
Isolated by vast stretches of ocean, the flora and fauna remained largely undisturbed by external influences for millions of years, evolving to flourish in their own unique natural environment. This situation continued until the arrival of humans around 700 years ago (Kolbert, 2014). From that time and especially during the last 200 years biodiversity plummeted in many areas as vast swathes of the natural landscape were destroyed and native animals were hunted sometimes into extinction. Introduced plants and animals were deliberately released or escaped into the wild and proliferated, outcompeting the native plants and animals which were poorly equipped to cope (Kolbert, 2014).
It was not long before New Zealanders realised they were in danger of losing many of their natural treasures and started to put measures in place in an attempt to halt the decline. As far back as 1892, the Land Act allowed the creation of flora and fauna reserves and offshore islands were gradually cleared of invasive pests and used as lifeboats for threatened species (Bellamy & Springett, 1990). However, the restoration of biodiversity especially in settled parts of the main islands proved far more difficult; it was necessary to create sanctuaries by enclosing areas of land within predator proof fences.
During the last twelve months I have spent several weeks staying with family at their home close to the Orokonui Ecosanctuary about twenty kilometres north of Dunedin. The idea of a sanctuary in the area was first conceived in 1982 and from this the Otago Natural History Trust was formed (Wikipedia, 2016). However, the idea did not come to fruition at that time, but was revived several years later when the Zealandia Wildlife Sanctuary opened in Wellington (Wikipedia, 2016). The Trust ran a fundraising campaign to help get the project under way. This was well supported with an enthusiastic local Dunedin community backing schemes such as 'sponsor a fencepost' (Wikipedia, 2016). In just a few short years, much progress has been made and many opportunities are now available for education, research and recreation.
Orokonui Ecosanctuary
Orokonui is a north facing valley through which the Orokonui stream flows, emptying eventually into the Orokonui estuary, an important area for wading birds. The sanctuary was enclosed in 2007 by a fence 8.7 kilometres long and 1.9 metres high protecting an area of around 307 hectares of regenerating native forest (Wikipedia, 2016). The mesh of the fence is small enough to keep out baby mice, a layer of gravel outside the fence covers a skirt at ground level keeping out burrowing animals and a stainless steel hood keeps out climbing animals (Wikipedia, 2016). The potential for overhanging trees permitting access is reduced by a perimeter road on both sides of the fence and a solar powered electric wire on top of the fence sets off an alarm if touched (Wikipedia, 2016). Visitor access to the sanctuary is via an airlock style double gate.
Predator proof fence
While the fence keeps pests out, those already living in the valley had to be eradicated before any native threatened species could be released. Eradication commenced in August 2007 with goats and possums shot and poison baits scattered from aircraft. In addition, local volunteer workers continued to support the project; many weed plants were removed and native seedlings raised at a nearby nursery were planted (Wikipedia, 2016). Rock piles were made to create habitats for lizards (Wikipedia, 2016).
Infrastructure at the sanctuary now includes a visitor centre, an aviary to house birds prior to release, bird feeding stations, an enclosure for Otago skinks which had become locally extinct and a viewing pen for two young tuatara. The tuatara is the sole survivor of an ancient line of reptiles found only in New Zealand, having become extinct elsewhere about 100 million years ago (Orokonui Ecosanctuary, 2016). Several well graded walking tracks meander through a variety of habitats close to the visitor centre. These include native grasslands, podocarp and fuchsia forests, an area planted with host and food plants to attract native butterflies and another planted with rare plants of Otago (Orokonui Ecosanctuary, 2016). Visitors are provided with a brochure incorporating maps and information on tracks, habitats, plants and birds. Information panels strategically placed along the tracks assist with plant identification.
Only one walking track, the Robin Valley Track, extends the full length of the sanctuary following the Orokonui stream almost as far as the estuary. Ten species of native fish including four galaxids are found in the stream, the southern end of which flows through tree ferns and native forests (Orokonui Ecosanctuary, 2016). Towards the northern end exotic forest persists and visitors are able to view New Zealand's tallest tree, an 81m high Eucalyptus regnans! An information panel here states that while this tree is a native of Australia, eucalypts did grow in New Zealand prior to the last ice age. Fossilised eucalyptus leaves have been found in Frasers Gully in Dunedin (Orokonui Ecosanctuary, 2016).
Stoat trap
Sadly, during the winter of 2015 the hard work experienced a set back when an unusually heavy snowfall settled on the perimeter fence providing an opportunity for one pregnant female stoat to climb over from the outside (Smith, 2016). Predator proof fences are apparently not infallible. Many traps were set, but this stoat was evidently trap shy; footprints were seen leading up to the traps, but the stoat never entered (Smith, 2016).
Twelve baby Kiwis were immediately relocated to safe havens (Smith, 2016). Prior to the breach, 50 to 60 rare South Island Saddlebacks were known to live in the sanctuary, these birds are particularly vulnerable to stoat attack; it appears that they are now extinct in the reserve (Smith, 2016). On the 5th November 2015 a stoat detector dog located a stoat den in the base of a Totara tree, the female stoat and her kits were caught and destroyed (Smith, 2016). In monetary terms it is estimated that this breach of the fence cost well over $10,000 (Smith, 2016).
Evidently, more needed to be done not only to ensure the ongoing protection of the sanctuary but also to improve the situation for nature beyond the perimeter fence. In recognition of these needs and inspired by the successes and lessons learned at the Orokonui Ecosanctuary, the Dunedin based Landscape Connections Trust developed and now coordinates a new project, 'Beyond Orokonui', in an area covering 55,000 hectares between north Dunedin and Waikouaiti including all the land immediately surrounding the Sanctuary (Beyond Orokonui, 2016). Much of this land has been altered for human uses. The community led project has a vision to restore and protect the natural landscape by repairing, extending and linking remnant native habitats and enhancing ecosystem health. As a result, it is envisaged that the health, wellbeing and sustainability of the human population will also be enhanced through the delivery of improved ecosystem services, the encouragement of responsible stewardship of the land and an increased connection to the natural environment (Beyond Orokonui, 2016).
A key element and priority focus of the Beyond Orokonui Project is the Halo Project which, plans to prioritise long term pest control in the area immediately surrounding the sanctuary (Community Consultation Document, 2016). It is a response to the essential requirement to protect the integrity of the sanctuary and also the safety of the flighted birds not confined within the fence (Community Consultation Document, 2016). My family's house and land is located within the halo. In the spring of 2015 letters were received by residents within this area seeking expressions of interest from those willing to partake in the project. The community response was extremely favourable and in May 2016 a community consultation and information session was held in the visitor centre. The attendance was overwhelming, the organisers ran out of chairs, it was standing room only for many of the late comers. I was fortunate to be able to attend this meeting (and even arrived early enough to grab a seat!).
In a speech in 2012 one of New Zealand's leading scientists, Paul Callaghan called on New Zealanders to strive to eradicate all introduced predators (Kolbert, 2014). At our information session, predator control on a landscape scale was explained by the two main speakers the Orokonui ranger and a pest management professional. While it was recognised that it is unlikely that New Zealand will ever in reality be able to rid itself of every introduced pest, it was considered that a concerted and ongoing community effort would be able to reduce numbers to a very low level giving rare and threatened species a chance to re establish in the wild.
Subject to sufficient funding being received, the Halo Project will employ a part time project manager and a full time field officer. The first priority will be to reduce stoat, possum and rat numbers significantly by organising the activities of groups of volunteers. The groups will defend patches along roadsides, tracks, beaches and streams called 'Community Controlled Pest Sites' (CCPS). They will strategically install and monitor traps and bait stations, monitor wildlife and collect data. A trainee program will facilitate the building of skills through theoretical and practical training in pest management. Residents, especially those living very close to the sanctuary will be encouraged and assisted with trapping and baiting on their properties.
In addition to helping wildlife, the Halo Project will also contribute to a resilient community. Controlling pests and restoring and protecting indigenous biodiversity over the long term will increase agricultural productivity. As new skills are gained through the training programs, it is envisaged that opportunities for employment will be created in the areas of nature conservation, pest management, small scale food production and eco tourism. This should encourage the local community to support the project into the distant future. It seems that nature conservation in New Zealand will be dependent on projects such as these and communities which will remain motivated and vigilant for a very long time.
The ecosanctuary is open to the public between 9.30 and 4.30 daily for guided or self guided tours. If you ever find yourself in the Dunedin area, it is well worth a visit.
References
-Bellamy, D. & Springett, B. (1990), Moa’s Ark, The Voyage
of New Zealand. Auckland, New Zealand: Penguin Books (NZ)
Ltd.
Beyond Orokonui (2016), www.beyondorokonui.org.nz, accessed 13 July
2016.
Cave, Y. & Paddison, V. (2nd edition 2002), The Gardener's
Encyclopaedia of New Zealand Native Plants. Auckland, New
Zealand: Jane Connor.
Kolbert, E (2014), 'Annals of Extermination, The Big Kill, New
Zealand’s crusade to rid itself of mammals', in The New
Yorker December 22 & 29.
New Zealand Wildlife Service (1985), New Zealand in the Wild; An
Illustrated A-Z of Native and Introduced Birds, Mammals, Reptiles and
Amphibians. Auckland, New Zealand: William Collins.
Orokonui Ecosanctuary (2016),
accessed 13 July 2016.
Smith, E (2016), 'The Tale of a Stoat', Otago Daily Times
Online, www.odt.co.nz, 8 February 2016, accessed 13 July
2016.
-Wikipedia
(2016), Orokonui
Ecosanctuary, accessed 10 July 2016.
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