I’ve written a few posts about the bush in Wellington recently, about remnants of the original forest that covered much of the Wellington peninsula before it was cleared by European settlers, and then about how the newly bare landscape was planted with and colonised by imported species. In my last post, I also wrote about how the native bush is returning helped by regeneration projects, often run by volunteers. Native birds are coming back too, through the work of the Zealandia sanctuary, the local and regional councils, and numerous community groups.
My friend Marc is leading a volunteer regeneration project in Polhill Reserve off Aro Valley and I met up with him a little while ago to find out more about it. Marc’s project is trying to restore the original forest and to improve the control of predators such as possum, stoats, rats and mice that feed on the eggs and young of native birds, compete with birds for food, and damage native bush. This is particularly important because the Polhill Reserve borders Zealandia, and Zealandia’s reintroduced native birds are starting to nest outside the predator-proof fence.
We followed a rough clay path knobbled with tree roots up into the reserve, past the strange dog training place. Marc pointed out a piece of orange plastic ribbon tied to a tree – a marker for a ‘chew card’ exercise that the project had carried out recently. ‘Chew cards’ are bits of hollow card filled with peanut butter, laid systematically along grid lines. Rats and possums are partial to peanut butter and their bite marks on the cards are used to get an idea of numbers and types of predators in the area. The results of the chew card exercise showed that there are significant number of pests in the area, including possum, despite the fact that the council has been trapping and laying poison in the area. Marc’s group are using the results of the exercise to work with the council on the best way of controlling predators in the area, and with the help of a council grant will carry out further monitoring to track progress.
The path took us along a ridge, through stands of pine trees and regenerating native bush including some impressively large tree ferns. Marc pointed out cherry trees, garden escapees that have seeded themselves. We passed a house, tucked surprisingly into the bush, its boundary guarded by a trio of spooky spider sculptures, a mother and babies.
The path crossed the ridge and snaked along the edge of the gully. On the opposite side, the houses of Aro Valley and Highbury clung to the steep hillsides. Looking up the gully, we could see the full extent of the area covered by Marc’s project – surprisingly large and also extremely steep. As with the chew cards, predator traps are laid along gridlines, regardless of topography. Fortunately the volunteers don’t seem to mind the challenging terrain.
We descended past a rustic-looking community house to the Waimapihi stream and then followed the stream up through the gully, crossing and re-crossing it, under a canopy of native māhoe trees. The waters of the stream are shallow and clear. Just below the community house, the stream is culverted for the rest of its passage through Wellington to the sea. There’s a weir above the culvert which makes it unlikely that fish could make the journey up the culverts to the open stream, although in other Wellington streams they do.
I like the open ground under the trees and the green light filtering through the dense cover of leaves above us, but according to Marc a grove of māhoe like this is potentially a problem for regenerating bush because nothing else grows beneath it. That’s the problem with messing with eco-systems. Nothing returns in the same way. Not only that, but because New Zealand’s forests are so unique and efforts to regenerate them are fairly recent, people are still learning about how to do it. But the bush is growing back at a remarkable pace – Marc says that some of the volunteers on the project can remember there being open pasture on the hills only about thirty years ago, while now the gully is completely covered in bush.
There are plastic tags on some of the trees to mark where traps are located and also places where people from the council stop and listen out for birds. We stop and listen at one of them, but all we can hear is the evening song of blackbirds.
We come to a collection of objects under some trees – a bench and a folding chair with a torn seat. Plastic butterflies are hanging in the tree branches. This is ‘Spirit Hill’, where strange things happen according to local lore. There is a trap near here that Marc wants to check. I follow him up a steep bank, scrabbling in the loose earth. I have to hang off a tree branch to stop myself from sliding back down while he looks at it. It has been sprung, but there is no sign of any animal inside.
We head back along the stream down to Holloway Road, stopping to eat peppery kawakawa leaves on the way.
I returned to Polhill a few months afterwards, mainly to try to take some better photos*, following the same track over the ridge and down to the stream. On the way down I stopped to answer my phone and a North Island robin appeared, the first time I have seen one outside Zealandia. Spirit Hill had been newly decorated with streamers of fabric dancing in the breeze and the broken chair had been repaired. I wondered if it was for a new spirit, or a fresh reminder of spirits past.
From Holloway Road I took a path that climbed steeply up a side gully and then zig-zagged up a ridge towards the Zealandia fence. I stopped to look at the view of the harbour, and two kereru flew past, landing in a tree a few metres away.
I crossed a small park to get to the Zealandia fence, following the narrow muddy path that runs alongside it down to the entrance. The path was presumably created so that the fence could be regularly checked, and it provides a handy route from the hill suburbs around Zealandia to the paths that lead to the south coast, but it always feels strange to me though to walk alongside a high fence, as if you’re skirting a prison or a contested borderland.
The Zealandia fence, 8.6km long and 2.2 meters high, is designed to keep out every possible species of marauding pest animal. Zealandia jokingly compares it with the Great Wall of China. There are other fenced sanctuaries in New Zealand, as well as offshore island pest-free islands where endangered native species have been reintroduced and protected. But you can’t have fences everywhere. There are estimated to be 30 million possums rampaging through the New Zealand bush. A huge amount of cost and effort goes into pest control in New Zealand, not just by volunteers, but also by local councils and government agencies such as the Department of Conservation. As well as traps, poisons such as 1080, cyanide and brodifacoum are scattered through New Zealand’s forests. It seems the only way to put right environmental damage is to create more of it, killing one species to save another.
The Department of Conservation depicts possums in evil poses on its website, just in case anyone has any misgivings about New Zealand’s war on possum, but possums are protected in their native Australia and people even go to look at them in zoos.
Recently, Gareth Morgan has been vociferously campaigning against cats, particularly in the Wellington suburbs around Zealandia. He has been doing some research on cat ‘trespasses’ using CCTV cameras and some dodgy-sounding extrapolation. Cats establish their own boundaries amongst themselves and have their own ways of dealing with trespassing, but Gareth Morgan seems to be talking about human-imposed boundaries. The ‘trespassing’ cats depicted in the CCTV footage are just cats doing their thing, just as the possums, rats, mice and stoats are doing what they do. Possums were introduced to New Zealand for the fur trade, rats and mice hopped off the canoes and ships of settlers, and stoats were introduced to deal with the introduced rabbits that had got out of hand. None of them asked to be brought here.
We give animals, and plants too, a place in a hierarchy of value depending on their economic worth, their cuteness and their effect on eco-systems that humans have already disrupted. Of course, we have to do something about the mess that we have created and I don’t suppose it’s even possible to do it in a way that isn’t laden with human-imposed values. But I don’t think we should forget that humans are the real possums.
Once I get down to the road I decide to have a quick walk in Zealandia before it closes. It’s already late by the time I get in, and the sun has sunk behind the hills. The narrow valley reverberates with evening birdsong. The trees by the side of the lake are alive with small birds darting through the branches – silvereye, grey warblers and whiteheads. A fantail flutters and swoops along the bank, and I can see saddlebacks slipping gracefully through the dense foliage of a māpou.
A little further on, the pied shags have settled on their roosting trees by the lake, some of them asleep with heads tucked under their wings. One is beating its wings noisily on the surface of the water. When I get down to the pontoon walkway along the lake I see there are shag nests in the tree branches. In one nest are two baby shags, nearly as big as the parent who is trying to feed them as they grab greedily at her beak. When she has finished, they sway manically from side to side in perfect unison as if they are joined together at the hip.
Most people I’ve seen have been on their way back to the entrance and it feels as if I have the sanctuary to myself. At the wetland area, I look across the sedge and there is one of the tākahe pulling at something it has found in the water. Standing on the boardwalk, I have the sense of witnessing something primeval, this big strange flightless bird, for many years thought to be extinct, rootling around at its own business in mud and water.
*I didn’t entirely succeed. Please just bear with me until I work out how to use my new camera.