Aotearoa Before Us II: Our Wetlands

The ground is soft beneath our feet. Fernbirds / Mātātā (Poodytes punctatus) call from the raupō. We step into a kayak and push off into a narrow, dark channel. The paddle dips quietly as we glide through flooded forest and swamp water.

This is the wetlands of pre-human Aotearoa — not pastureland, but vast, living landscapes that once covered much of lowland New Zealand. A thousand years ago, scenes like this were common. Today, they are almost unimaginable.

Wetlands form in a variety of ways and environments, but the type of wetland we are paddling through now is a swamp — fertile, nutrient-rich, and filled with sedges, rushes, flax, and towering kahikatea. The plants in these waters add oxygen, provide shade and shelter for many species and filter and cool the water. These wetlands provide habitat for countless animals, including species no longer with us.

On the water, we see a variety of ducks dabbling, including some now extinct. Many of these species are closely related to Australian counterparts, such as the Scarlett’s duck (Malacorhynchus scarletti), a filter-feeding duck with a large flat bill, closely related to the Pink-eared duck (M. membranaceus). Very similar in appearance, Scarlett’s duck was twice the size, tipping the scales at 800 g compared to the Pink-eared duck’s 480 g.

This trend continues with the New Zealand Musk Duck (Biziura delautouri), which was not only 10% larger than the Australian Musk Duck (B. lobata), but also had shorter wings and longer legs, suggesting it was more terrestrial than its relative. The one we see here is a large male at 2.6 kg, with a prominent bill lobe hanging down for display, much larger than the females lurking in the flax.

Not all ducks were larger, though. The New Zealand blue-billed duck (Oxyura vantetsi) was actually smaller than the Australian blue-billed duck (O. australis). They look similar to our Scaup (Aythya novaeseelandiae), but can be distinguished by their bright blue bills.

Beneath us, we see the large, dark shape of a Longfin Eel (Anguilla dieffenbachii) cruising under the kayak. Today, finding an eel of this size — two metres long and weighing up to 50 kg — is rare due to habitat destruction and overfishing, as these eels became an important food source. In pre-human Aotearoa, however, they were far more common. Longfin eels are apex predators of wetlands, controlling invertebrate and fish populations and helping keep waterways healthy. They also host freshwater mussel larvae, which later filter water as adults. The migrations of eels and galaxiid fish like kōkopu help cycle nutrients between freshwater and ocean ecosystems.

We then see a pair of large black swans followed by fluffy cygnets. These are not the Black Swan (Cygnus atratus) seen today, but the extinct New Zealand swan / Matapu (C. sumnerensis), 30% larger, with longer legs and a more robust skeleton. Like many New Zealand birds, it evolved to be more sedentary in a land free from mammalian predators.

The Black Swan, the New Zealand Swans closest relative

Crashing and booming sounds erupt from the flax beside the riverbank, followed by the splashing of something large. A mated pair of Heavy-footed moa / Moa waewae taumaha (Pachyornis elephantopus) emerges. Found in the lowland areas of the South Island, this was the third-largest moa species behind the giant moa, with females weighing up to 160 kg and standing up to six feet tall with neck raised. Wide-bodied with large feet, they push easily through dense foliage, though they struggle slightly in the muddy swamp, their mottled feathers caked with mud.

We also begin to see species more familiar today, such as the New Zealand dabchick / Weweia (Poliocephalus rufopectus), Grey duck / Pārera (Anas superciliosa), and Brown Teal / Pāteke (Anas chlorotis). Today, these species are rare, with pāteke numbering only in the thousands. On our wetland journey, however, they are among the most common birds we encounter — before hunting, wetland drainage, and introduced predators drove their numbers down.

A bird unfamiliar to us uses its long serrated bill to catch an īnanga (Galaxias maculatus), swallowing it whole. This is the New Zealand merganser / Miuweka (Mergus australis), part of a family of specialist fish-eating waterfowl found worldwide. This species survived European arrival in the Auckland Islands but went extinct on mainland Aotearoa before then.

A painting of the New Zealand merganser done in 1909

Another bird that survived into European times was the New Zealand little bittern / Kaoriki (Ixobrychus novaezelandiae), a close relative of the Little bittern (Ixobrychus minutus), now only a rare visitor to Aotearoa. We see it standing motionless at the water’s edge, giving the classic bittern stare.

Pulling the kayak ashore, we stir the sediment to see what else lives here. We find a Canterbury mudfish / kōwaro (Neochanna burrowsius), today critically endangered but once common in wetlands. These remarkable fish can survive out of water in damp refuges if wetlands dry out. Today, they are threatened by agriculture and irrigation changes.

We also see the shapes of sleek, silvery fish, looking like the now extinct New Zealand grayling / upokororo (Prototroctes oxyrhynchus). They migrate between rivers and the sea, much like whitebait species today. Early accounts described them moving upstream in large shoals through wetlands and rivers across both the North and South Islands. Highly valued as food, they were heavily fished soon after European settlement, while habitat changes and introduced trout added further pressure. By the early 20th century the upokororo had vanished, becoming New Zealand’s only confirmed freshwater fish extinction — a quiet reminder of how quickly even abundant wetland species can disappear.

In the reeds, we spot the shape of a large rail — too small to be a Weka (Gallirallus australis), yet much larger than an Australian crake (Porzana fluminea). This is the New Zealand Giant Crake (P. hodgenorum), at 250 g, far larger than its 65 g relative. Once thought to be a small native hen, genetic studies revealed it to be a crake species.

Nearby, the New Zealand Coot (Fulica prisca), weighing 1.8 kg, dwarfs the Australian coot (F. atra) at 570 g. Although wetland birds, these coots were more terrestrial than their relatives and ranged into forested and subalpine habitats.

As night falls, we hear heavy crashing near camp. Shining our torch, we see a small group of Eastern moa / Moa mōmona (Emeus crassus). Smaller at around 80 kg and one metre tall at the hips, this South Island species had been expanding since the last ice age into habitats revealed by retreating glaciers — an expansion cut short by human arrival, being one of the most common species that will be hunted by Maori settlers.

Leaves rustle nearby, followed by a splash. A Southern brown kiwi / Tokoeka (Apteryx australis) emerges. Today found on the West Coast and Stewart Island, it once ranged further along the eastern coasts of the South Island . Like some North Island Brown Kiwi (A. mantelli), this bird is foraging in the wetland, pulling up a Southern kōura / freshwater crayfish (Paranephrops zealandicus) — a welcome meal. 

Since human arrival, over 90% of Aotearoa’s wetlands have been drained for farmland and agriculture. Stock damage vegetation and pollute waterways, causing algal blooms that kill wildlife. Drainage prevents wetlands from reforming, and invasive plants outcompete native species. Many birds mentioned here have been found in Māori middens, hunted for food and tools, while introduced predators like kiore, stoats, and ferrets compounded the damage. Combined with habitat loss, this drove many species to extinction.

Wetlands act as natural sponges during heavy rain, absorbing and storing excess water before it can rush downstream. By slowing the flow of floodwaters, they reduce the height and speed of floods, easing pressure on rivers, bridges, roads, and stopbanks. Wetland soils and vegetation also trap sediment and stabilise banks, preventing erosion that can damage infrastructure. In doing so, wetlands don’t just protect habitats — they protect homes, farmland, transport networks, and ultimately human lives by reducing the risk and severity of flooding events.

Wetland restoration is increasing across Aotearoa, with planting, re-flooding, and rehabilitation projects underway nationwide. Degraded farmland is being reshaped to allow water to pool and flow naturally again, drains are being blocked, native sedges and rushes replanted, and stock excluded to give fragile ecosystems a chance to recover. Community groups, iwi, conservation organisations, and government agencies are working together to restore these once-vast landscapes — recognising not only their biodiversity value, but their importance for water quality, carbon storage, and flood protection.

Alongside habitat restoration, species recovery is also playing a crucial role. Birds like the pāteke are being bred and released by facilities such as Ōtorohanga Kiwi House into safe, protected wetlands like Rotokare in Taranaki. These sites are secured by predator-proof fencing and ongoing pest control, giving vulnerable native species the opportunity to re-establish stable populations. With time, patience, and continued commitment, these restored wetlands can once again support the rich web of life that once defined lowland Aotearoa.

The wetlands of pre-human Aotearoa we paddled through may seem distant, but they are not beyond memory. They remind us that these landscapes once thrived — and that with care, knowledge, and commitment, they can return.

References 

Home page | New Zealand Birds Online. (n.d.). Www.nzbirdsonline.org.nz. https://www.nzbirdsonline.org.nz/ 

What kiwi eat. (n.d.). Save the Kiwi. https://savethekiwi.nz/about-kiwi/kiwi-facts/what-kiwi-eat/

Loss of wetlands continues. (2019, March 7). Predator Free NZ Trust. https://predatorfreenz.org/research/wetlands-loss-southland/ 

Costanza, R., Anderson, S. J., Sutton, P., Mulder, K., Mulder, O., Kubiszewski, I., Wang, X., Liu, X., Pérez-Maqueo, O., Luisa Martinez, M., Jarvis, D., & Dee, G. (2021). The global value of coastal wetlands for storm protection. Global Environmental Change, 70, 102328. https://doi.org/10.1016/j.gloenvcha.2021.102328 

“OUR ACHIEVEMENTS | OtorohangaKiwiHouse.” OtorohangaKiwiHouse, 2025, www.kiwihouse.org.nz/our-achievements  Accessed 28 Feb. 2026.