Tūpari Reserve

09/06/2026

Ivy (Hedera helix) has a real Dr Jekyll and Mr Hyde personality. As a garden plant, it can seem quite appealing: an easy-to-grow evergreen ground cover with attractive leaves that come in a variety of shapes and colours. Unfortunately, ivy also has a far darker side. It’s a notorious garden escapee that ranks among the most troublesome weeds in Tūpari Reserve.

While growing along the ground, ivy thrives in deep shade, smothering the forest floor and occupying valuable real estate that would otherwise be available for native plants. However, once it finds a tree trunk, or other structure to climb, ivy undergoes a remarkable transformation when it finds sunlight. The familiar creeping stems with their classic lobed ivy leaves are replaced by a very different-looking beast with larger, unlobed, diamond-shaped leaves. This version of ivy flowers and produces berries that enable it to be spread on the wings of birds.

The climbing stems of ivy attach themselves to structures using multiple, modified aerial roots that secrete a natural glue. Anyone who has pulled ivy off a building knows the powerful adhesion they provide as aerial roots remove paint rather than surrender gracefully. A mature ivy infestation can weigh several tonnes - a comparable weight to a car. That is a tremendous burden for a tree to carry, and the extra weight can eventually cause branches or entire trees to collapse.

Despite its dramatic transformation and clever survival techniques, both the Dr Jekyll and Mr Hyde versions of ivy share one weakness: herbicide. The climbing stem is the easiest to kill if cut low and herbicide paste or spray applied to the stump - the vines then slowly transform to our favourite form of ivy - a dead one.

04/06/2026

New Zealand pellitory (Parietaria debilis) would, at first glance, probably be described as "boring". Even its name hints at this: debilis is Latin for "weak", "frail", or "small". It's a modest little herb with mid-green leaves and tiny greenish-white flowers that can be present almost year-round. Foodies might get excited because I've used the word "herb", but in botanical terms this simply refers to a flowering plant without a woody stem. Practically speaking, herbaceous plants are the ones that can be tossed straight into the green bin without needing to be jumped on for compaction - unlike their bulkier tree and shrub cousins.

One of the greatest lessons I learned while working as a sexual health doctor is that there are no boring people. Everyone has an interesting backstory, and you certainly can't judge a book by its cover. The same applies to our flora and fauna, and New Zealand pellitory is no exception.

A member of the nettle family, New Zealand pellitory is also native to Australia, but it has managed to spread across a remarkable swathe of the globe, making it one of New Zealand's most widely distributed native plants. Today it occurs throughout much of Africa, Asia, Australia and New Zealand, as well as on numerous islands and in other temperate regions.

Its inconspicuous appearance means it is less likely to be photographed and uploaded to citizen-science platforms such as iNaturalist. Despite its low profile, it was noticed by Joseph Banks during Captain Cook's first voyage to Aotearoa, and was formally described in 1786 by the naturalist Georg Forster. It typically grows in shady, damp habitats, coastal bush, rocky outcrops and forest margins and is known to colonise nutrient-rich bird poo piles.

Its most exciting secret (from a human view point), is its connection to one of New Zealand's most striking butterflies. New Zealand pellitory is a native food plant of the yellow admiral butterfly. Female butterflies use chemical cues to locate pellitory plants and lay their eggs on the undersides of the leaves. The caterpillars then munch on the leaves until they are ready to pupate.

Without the seemingly bland, we wouldn't have the beautiful.

01/06/2026

https://www.youtube.com/watch?v=oqAgApS4QNQ
There’s a good chance the algorithms of the Meta-verse have already served this video up to you. It was made by MAS, the organisation that looks after our insurance and KiwiSaver, as part of a members’ showcase.

M&M are generally more comfortable being mikimiki - small-leaved, hard-to-classify shrubs, than aspiring B-list movie stars, so appearing in a video like this comes with a generous helping of cringe factor. That said, we’re passionate about natural regeneration and the remarkable way it can grow an entire forest without anyone planting a single tree.

If you’re curious about this everyday miracle, feel free to watch. And if the fairy-tale-like story of how two medically trained people ended up living in a house truck, subsisting on a muesli-rich diet and foraged mushrooms sounds intriguing, then the fictional tale (based on a true story) might also be worth a read.

Link to the magazine article in the comments.

Canterbury conservation crusaders Mark Nixon and Megan Reynolds are dedicating their time and resources to restoring Kaituna Valley’s flora and fauna.

28/05/2026

As autumn slips into winter, our old man’s beard control efforts are carried out quite literally beneath a fluffy cloud of old man’s beard seed. At times it can make the whole exercise feel a little futile - as a vine of Clematis vitalba (old man’s beard/OMB) can produce more than 100,000 seeds in a season; as we work, cutting and poisoning vines, there is often a gentle drift of seeds floating groundward, each one seemingly full of optimism about putting down roots and creating more work for us later on.

We are often asked whether autumn and winter is too late in the season to tackle old man’s beard? A study published by Massey University looked at seed viability in the aerial seeds and thankfully, for those of us in the OMB killing business, the results are encouraging. Seed gathered in May had an extremely low germination rate of just 0.2%. By comparison, around half of the seed still hanging on vines in winter (June/July) germinated, while by September up to 85% of aerial seed would successfully sprout.

Practically speaking, this means the more vines we kill now, the fewer seeds will mature enough to germinate later. As a plus old man’s beard leaves are turning yellow at the moment which makes identification even easier. In our books, any times a good time a good time to kill old man’s beard.

25/05/2026

A digger has been clearing some of the access-blocking carnage left behind by February’s weather bomb. It has been a joy to revisit parts of the reserve that have effectively been locked away for three months. Like needy parents we have missed visiting, but nature has just kept growing during our absence. Once the digger has restored order the freshly exposed track banks look alarmingly naked and vulnerable. This contrasts with our older track banks, with their patchwork of lichens interspersed with grasses and mosses. Shrub seedlings, including kānuka and our ever-present friend-and-foe gorse, are also starting to get a root hold onto the banks.

Today’s showy bank resident is lichen Dibaeis arcuata. Like all lichens, it is not a single organism but a composite organism formed by a symbiotic relationship between a fungus and an algae or cyanobacteria. A perfect example of a co-dependent, interspecies marriage, with strict old fashioned partner roles. The fungus provides structure and protection, while the algae provides food via photosynthesis. The fungi partner is also the master of the sexual reproductive department.

For much of the year Dibaeis arcuata can look fairly dull, appearing as a powdery grey crust on the soil. But when its fruiting bodies emerge, it’s a track-side star with distinctive pink-orange “lollipops” perched on curved white stalks. Those stalks are built from fungal hyphae (thread-like filaments), while the pink apothecia at the top functions as a spore-launching platform. Inside are microscopic pressurised sacs called asci that literally fire fungal spores into passing air currents, a delightfully dramatic strategy for leaving home.

While all this sexual shenanigans is going on, the algae partner keeps the lichen ‘marriage’ in food by harvesting sunlight. As they say in the lichen world – behind every great fungus is a great algae.

21/05/2026

Changing leaf colour is one of autumn’s trademark moves. But leaves are not the only things that change as the days shorten and temperatures drop. At this time of year Nezara viridula shifts from bright green to a mottled brown form.

Originally from Ethiopia, it’s a bug that now calls home the world between the 45th parallels north and south. In New Zealand, this latitudinal line cuts across the South Island just north of Oamaru. With such a large home range this bug has naturally picked up a few different names along the way. The British call it the green shield bug, Americans know it as the green stink bug, and here in Australasia we call it the green vegetable bug.

Vegetable bugs thrive in warm conditions and can breed year-round, but they can’t survive in places where the average winter temperature drops below 5°C. Living on the chilly edge of their comfort zone means winter can be deadly. A vege bug stands a better chance of surviving our colder months if it’s a lady, large and lightly browned. So as the temperature drops the adults temporarily change their ‘shell’ colour to a shade of brown.

As well as changing colour with the seasons, these bugs sport some remarkably funky outfits as they grow. Like all insects, vegetable bugs wear their skeleton on the outside, so growing up means regularly shedding their “hard skin”. Each new stage between moults is called an instar, and at every instar they seem to reinvent themselves with some pretty exotic looking costumes. Some instar stages look so distinctive you would swear they were entirely separate species.

16/05/2026

Recently we drove into area of rank grass that looked like something from a Halloween movie set, with cobwebs draped over everything.

The proceeding days have been sunny with only the gentlest breeze, perfect conditions for spiders to take flight. The technical term is “ballooning”, where baby spiders leaving home by revving up their spinnerets and releasing a fine thread of silk from their backsides into rising air currents.

On sunny days we often spot long, sun-catching threads drifting high across the sky. Each one carries a tiny spider off to new hunting grounds. The likely creator of this apocalyptic, anxiety-inducing scene for arachnophobes is probably a spider from the genus Allotrochosina.

These native spiders belong to the wolf spider family (Lycosidae). Rather than building webs to trap prey, they are active hunters, relying on speed and surprise to pounce on their victims. Instead of spinning b***y traps, Allotrochosina use their silk as parachutes, an inventive and ingenious evolutionary adaptation.

10/05/2026

This morning we enjoyed a fantastic rock hop up the stream as part of the Banks Peninsula Walking Festival. Coincidentally, it fell on Mother’s Day, and we were delighted to be joined by several young people, including our son, along with a couple carrying their baby in a backpack.

Everyone donned helmets and we set off just as the weather rolled up the valley. We clambered over rocks, crossed flowing water and admired the towering podocarps lining the stream, which happily sheltered us from the occasional drizzle and gust of wind.

Twenty-one-month-old Rowan’s parents gave us a masterclass in attentive, loving adventure parenting, while our 21-year-old lad scaled waterfalls that perhaps would have been better left unclimbed. The rest of the party wisely took the pre-prepared detours around them.

Happy Mother’s Day to all the mums and mother figures out there, and a little extra love to those whose mums are no longer here to celebrate with.

06/05/2026

Let’s do it, let’s fall in love. Written by Cole Porter for his 1928 Broadway musical Paris, the song is credited with popularising the euphemism “the birds and the bees.” I couldn’t help humming, “Birds do it, bees do it, even educated fleas do it.” when I came across these German wasps ‘doing it’ beneath a ngaio leaf.

As autumn approaches, wasp nests produce virgin queens and male drones, and on sunny days the uppermost leaves of tall shrubs hum with anticipation as males mill about, waiting for a queen to pass through their swarm. Wasp courtship is complicated. Their mating involves swarms of waiting drones, pheromones, and polyamory, with most queens taking several partners. Each “let’s do it” session lasts about ten minutes.

When I spied this particular couple, they were knotted together. After a few minutes, the queen seemed keen to move on. As I watched, she began biting at the male’s abdomen, as if to say, “Enough’s enough, on your bike, mate.” Eventually, he got the message, disengaged, and flew off.

The queen would store s***m collected from multiple suitors in a specialised internal sac, then find a place to hibernate over winter before starting a new colony in spring. But, knowing the detrimental effect of German wasps on our native insects - I squashed her.

04/05/2026

On Saturday morning we had the pleasure of guiding 15 walkers along a brand new section of track as part of the Banks Peninsula Walking Festival. The first half of the walk wound through beautiful native bush, with fantails flitting alongside us and the stream never far away. We then joined the lower section of the Reserve’s four month old, Packhorse Hut Track. With the sunshine on our backs and sweeping views down Kaituna Valley to Te Waihora time passed quickly.

One of the real highlights of the festival is the people. Walkers are always an interesting bunch, and it was a pleasure to reconnect with familiar faces from past festival tracks while also making new contacts.

If you have not yet experienced the Banks Peninsula Walking Festival, there is still time. There are some fantastic walks on offer, including one of ours this Sunday morning.

Join us for a true adventure: a scramble up a mountain stream, past two waterfalls, and into a remarkable stand of ancient kahikatea, tōtara and mataī. We still have places available, so come along, challenge yourself, enjoy nature, and meet some great people along the way. Tickets available on the Rod Donald, Banks Peninsula Walking Festival site.