The Otago Daily Times' Richard Davison talks to project leader Francesca Cunninghame about the experimental project, and her ambition to leave a legacy of growing biodiversity for future generations of visitors.
The Catlins delivers its fair share of ''wow'' moments as you make your way down the Southern Scenic Route, but perhaps none stick in the visitor's mind as powerfully as Florence Hill lookout.
For the car-bound tourist already feeling spoiled by Papatowai's pristine seaward vistas, all of a sudden the panoramic cup is overflowing, as a truly world-class view over Tautuku Bay and its neighbouring podocarp rainforest rolls out before them.
Brakes are applied, seatbelts released, and cameras given a scenic thrashing, before driving on to the next deep-south treat.
However, for the more adventurous explorer, the apparently dense and inaccessible forest seen from the lookout will willingly yield more intimate secrets, and a nearby detour into Forest & Bird's Lenz Reserve offers up a range of bush walks from a few minutes to two or three hours.
It's here that an experimental biodiversity project - the Tautuku Restoration Project - has been quietly ticking along since June 2016, led by Dunedin Forest & Bird project manager Francesca Cunninghame.
Beginning in the 550ha reserve, the project has since spread outwards into a further 800ha of the wider Tautuku catchment, which comprises Doc-managed estate encompassing the Tautuku and Fleming rivers.
Ultimately - given sufficient funding, and evidence of its effectiveness in achieving its aims - the project aspires to control pests and expand biodiversity throughout the entire basin, some 6600ha.
The project's experimental nature - and its complexity - derived from the unknown quantity of conducting pest control in a mixed podocarp forest, Cunninghame said.
Much had been learnt about effective pest control in beech forest over the years but, for podocarp, it was a different story.
''Apart from a miraculously-unlogged, pristine coastal strip, the majority of the forest here is historically-logged, regenerating mixed podocarp - mainly rimu, kahikatea and matai with extensive undergrowth.
''We don't know much about predators' boom-bust cycles in this sort of environment, so that's something we're learning as we go along, and hope to share with similar projects elsewhere in New Zealand.''
From a practical point of view, the project mechanics are relatively simple, if labour-intensive.
Using a standardised Doc 200 trap design - many built by Otago Corrections Facility inmates - riparian and strategic trap lines are gradually being extended to control the impact of stoats, rats and, to a lesser extent, hedgehogs in the target areas.
From a starting base of just 53 traps in 2016, there are now more than 500 in place, creating protective lines totalling 35km.
As predator numbers go down, the numbers of native birds increase, in particular, it is hoped, those of red and yellow-crowned kakariki, kaka, and the rifleman.
Longer-term ambitions extend to reintroduction of now-absent, nationally-threatened species formerly prevalent in the area, such as whio (blue duck).
However, Cunninghame is emphatic that will not happen until further steps are taken to conserve Tautuku's existing biodiversity.
''I'm a great believer in biodiversity for biodiversity's sake, so one thing we've worked hard to establish since the project began is exactly what we have here in the first place. There's absolutely no point in starting to reintroduce exciting new species if we're not doing whatever we can to conserve and propagate what's here already. It doesn't matter if some of those are less glamorous than others; they all count.''
It's possible she has in mind a nationally rare but locally abundant galaxiid fish, aptly named Galaxias gollumoides, or the Gollum galaxiid, after Tolkien's cave-dwelling creature.
Electric fishing last year established the presence of significant populations of the ill-favoured Gollum, and it turns out it's not alone in its cryptic lurking.
After sightings last winter, the threatened, typically shy Tautuku gecko has also popped up on Cunninghame's radar.
''It's a very beautiful, greeny-brown reptile, endemic to the Catlins and rarely seen. Now we know it's here, we want to better understand its distribution, and take appropriate steps for its conservation.''
With such an abundance of recently discovered - and, perhaps, as yet undiscovered - riches in the catchment, Cunninghame hopes to attract further funding and additional volunteers.
Due to the relatively low profile of the project to date, combined with its remoteness, she said volunteers had been limited to a highly dedicated core of about 10 Forest & Bird members, supplemented by concerned locals.
Doc community funding would maintain her role to the beginning of next year.
Although the project is not Cunninghame's sole activity - she also works with mangrove finches in the Galapagos, and with seabirds in Dunedin - she believes it is deserving of wider community support.
''Our volunteers put in incredible hours clearing trap lines, and installing and checking traps.
''They do it because this is a profoundly beautiful place, the largest fragment of native forest on the south coast, and something worth fighting for.''
Mother to two-year-old Niko, who joins her on each of her forest adventures, the ambition to preserve and enhance the world's ''special places'' is what fires her personally.
''What world do we want to leave for our children? I'd like to think there will still be beautiful places full of wildlife to explore for Niko and his friends, and their children in turn.
''It's sad to think of forests echoing in empty silence.''
• What: Tautuku Restoration Project.
• Where: Tautuku Forest, nr Papatowai, Catlins.
• When: Started June 2016, funded until early 2020.
• Who: About 10 volunteers, led by Forest & Bird project manager Francesca Cunninghame.
• Why: Conserve and propagate native species including kakariki, kaka, rifleman, Tautuku gecko, galaxiids and, eventually, reintroduced whio.
• How: Walking tracks in the forest's Lenz Reserve are signposted from the Southern Scenic Route, 6km south of Papatowai.