How many takahe are left in the world

The gorge leading to Lake Orbell sprouts tree-trunk icicles along its walls, the lake itself freezes solid and DoC staff wear heavily insulated Antarctic surplus boots.

Despite almost two decades of intensive efforts, despite eggs and chicks shuttled by helicopters, despite weeks and months spent in the field by dedicated and enthusiastic DoC staff, the last summer headcount revealed just birds. Just how, in an evolutionary sense, did the takahe find itself in such strife? It flies with a contorted jerky motion, but only for a short distance, alighting on any tree handy, and staggering among the branches as if intoxicated.

It walks as if troubled with corns, and in running it often stumbles. When swimming it looks like a domestic fowl tumbled in a water butt and wanted some kind friend to rescue it.

Its diving is still more absurd. Despite its ungainly predisposition, the pukeko proved to be a most successful coloniser. In some parts of Otago and Southland they were becoming a nuisance and a price was put on their heads. At first glance, the difference between the two birds is obvious: pukeko can fly, takahe cannot.

Pukeko are omnivores, takahe, except for the first two weeks, when the chicks are fed insects, are predominantly herbivores though this may be more out of necessity than choice. Pukeko can live in large groups with the intricate hierarchy of a wolf pack, build communal nests which can contain up to 25 eggs, and mob a predatory intruder when threatened.

Takahe appear to pair for life, usually lay only two eggs a year, and in the wild barely manage to bring up even a single chick. The jester and the aristocrat. Did the latter take a wrong turn in the race for survival?

Apparently not. Given an island habitat, evolutionary latitude and crucially a lack of ground-based predators, swamp hens such as pukeko will evolve into the likes of takahe time and time again. There were once takahe-like birds on the islands of Mauritius and Reunion, as well as on Lord Howe Island, east of Australia.

There was also a bird almost identical to the takahe in New Caledonia. As for our own takahe, there were, in fact, two distinct species, one from the North Island and one from the South. Maori called them moho and takahe respectively. Moho, the larger of the two and now known only from the subfossil remains, was shaped more like a pukeko: taller, flightless and not as bulky as its South Island counterpart. Given evolutionary time, it would almost certainly have become heavier and more takahe-like.

It never got the chance. In the autumn of , a surveyor named Morgan Carkeek, working in the north Ruahine Range, caught and brought down such a bird. He took it to the home of one Roderick McDonald of Horowhenua, where local Maori identified it as a mahoau. The arrival of the bird was such an event that it brought in a pilgrimage of Ngati Muaupoko elders. No moho was ever seen again. Another difference between moho and takahe has recently come to light, thanks to DNA analysis conducted by Trewick.

What Trewick postulates is that moho and takahe did not diverge from a common ancestor once the land-bridge connecting the North and South Island had submerged in the wake of an ice-age meltdown.

Rather, that moho and pukeko had a common ancestor in Australia, while the takahe, which is genetically closer to South African swamphens than it is to either moho or pukeko, traces its lineage back to a different ancestor—perhaps one which flew here from South Africa. Like moho and takahe, they were thought to be the same bird, but in fact they evolved independently from a similar ancestor, a pigeon.

Closer to home we have the case of the giant coot—one on the mainland, the other in the Chathams. The evolutionary path taken by both moho and takahe, towards flightlessness and large size gigantism , has been the one favoured by numerous birds on isolated islands where mammalian predators were absent: moa, kiwi and kakapo, the elephantbird of Madagascar, dodo and solitaire of the Mascarenes, giant owl of Cuba and ostrich-like mihirung of Australia, to name just a few see New Zealand Geographic, Issue But giving up your wings is a risky venture—a one-way road with not enough room to turn around.

No bird has ever evolved the other way, changing its mind, as it were, and regaining its ability to fly. When humans arrived in New Zealand, letting loose such a pandemonium of pets and vermin that the avian Eden became awash with bloodthirsty predators, for birds like takahe the road to flightlessness suddenly turned into an evolutionary cul-de-sac.

During a trip to Big South Cape Island, off Stewart Island, naturalist Herbert Guthrie-Smith reported that the nearly flightless Stewart Island snipe was so unafraid it could be stroked as it brooded its eggs. One grasp of his powerful claws would crush either of those animals, but he has no idea of attack or defence. In , a feral Alsatian mauled some northern brown kiwi before finally meeting a bullet.

This level of annihilation could endanger even populations which are relatively stable; for a species balancing on the brink of extinction, it could be the final push. Flightless birds are up against formidable foes.

Take the stoat, for example. Agile and ferocious, it can swim over a kilometre, can hunt eels if it chooses, and is a prolific breeder. This thing deserves to live! Clever, too. The national average for stoat trapping is one kill for every trap-nights. Geoffrey Orbell remembers how, during a fishing trip to the Eglinton Valley, a freshly caught trout was hung on a horizontal wire stretched between two trees.

Some time later, the fishermen saw their quarry swinging widely but in an odd slow-beat rhythm. Then they saw the stoat: climbing up a tree, leaping across to grab a flying bite from the fish, dropping to the ground, climbing up the tree. Again and again. The tranquilliser was wearing off and the stoat began to wake up. Then it just slithered away, like a snake, dragging its limp feet. With its habitat disappearing and predators encroaching, the takahe—a bird of forest margins, never numerous but once reasonably widespread—began to live an increasingly marginal existence.

It found a temporary refuge in the lost world of the Murchison Mountains—ranges that look more suited to a mountain goat than a bulky flightless bird. When you watch them blundering around in deep snow, or when you see the hardy mountain beeches that died of frost, it makes you think that, perhaps like the moa and the kakapo, and like the Hawea people, takahe found themselves in this harsh and inaccessible terrain because they had nowhere else to go.

I see my first bird, a female namedll, on a ridge near the lighthouse. Its feet are red, as if eternally cold, and it walks with a slow robotic strut, yanking out grass shoots the way a gardener might strain to pull out an oversized parsnip, sometimes almost falling over backwards.

Unlike the Murchisons, Tiritiri Matangi—one of the 47 islands in the Hauraki Gulf Maritime Park—is an open sanctuary, meaning that anyone can visit.

From on, the ha island was a sheep farm and, except for a few inaccessible gullies and the rocky coastal strip, it was razed of its forest and turned into one big paddock.

But in , the tide turned. Rats were exterminated and small streams dammed to create pond habitats. Then, into the regenerating and predator-free forest, birds were released—refugees from the mainland and transplants from other island sanctuaries: saddlebacks and brown teals, whiteheads and red-crowned parakeet, five pairs of little spotted kiwi and several takahe.

Piece by piece, a sketchy replica of a prehistoric ecosystem was recreated. Today, walking through the Tiritiri forest is like stepping back in time. Within minutes of turning down a gravel track I see my first-ever saddleback, preening on a coprosma bush.

Another one lands on a storm-soused branch above my head and showers me with droplets of rain. I see three kokako feeding on houpara leaves, holding them with their feet parrot-fashion, balancing on gangly legs that are ringed with coloured bangles. I am told that the kokako nearest me, banded red, yellow and green, has been nicknamed Bob Marley.

Such an environment allows an opportunity to study the birds on a day-to-day basis—a luxury that is almost impossible in the wilds of the Murchisons, where every trip is an expedition. For example takahe were always thought to be vegetarians, but on Tiritiri the details of their diet have been precisely determined.

It turns out that although the great bulk of their diet is grass, clover and seeds, the birds spend 6 per cent of their time foraging for invertebrates. They have been seen pursuing sandhoppers on the beach, looking under small logs in streams for aquatic insects, digging for worms in the bush, snapping up craneflies and cicadas from around the bases of cabbage trees and other shrubs—one even broke off a small branch to get a cicada that was out of reach.

Nor are the birds as placid as had been imagined. A three-kilogram bird can exert a 10 kg pull, and so the injuries are frequent and often serious. On occasions, Barbara Walter and her husband Ray have acted as paramedics. One morning, after hearing the dawn chorus performing at full volume, I join Ray on the daily patrol, bouncing along the network of maintenance trails spanning the island on the back of a quad bike. Ray, an ex-lighthouse keeper with a white Papa Hemingway beard, has lived on Tiritiri for the past 18 years, and conditioned the birds to show up for a headcount every morning.

Their appearance is rewarded with a handful of pellets, and the handout also attracts other opportunists: a mob of pukeko follow the bike, running fast, flapping their wings for an extra boost of speed. Ray suspects that due to a mild winter they have already started nesting. Perhaps hawks are a natural predator.

They like the attention of the visitors, and even more so the food pellets that come with it. I watch one bird pull out a particularly juicy morsel, which, after the recent rain, must seem too soiled for immediate consumption. Ray explains.

They have 20 takahe on the island, but only four breeding pairs. Of those four, one produces consistently infertile eggs. Another pair, awkward as they are, break their eggs while swapping the nesting duties. The other two pairs produce, say, three chicks.

One is snatched by a gang of pukeko, another one by an eel, the third dies of an infection. The net growth of the seemingly healthy population is zero. Before leaving the island I treat myself to a CD of native birdsong and make a mental note to use it with a timer as a morning wake-up call.

Like island sanctuaries, it is a substitute for the real thing. On my last evening I again sit under the lighthouse, watching clouds lit by a nearly full moon sail across the sky. Somewhere in the forest a little spotted kiwi shrieks. There are now some 50 birds protected in this genetical safety cache on Mana, Maud, Kapiti and Tiritiri.

The success of the island project has led to speculation that perhaps the birds should not be released into the Murchisons at all. Takahe are basically just big pukeko. However when pushed, they are strong fliers and can fly long distances if needed. Pukeko lack webbed feet, but are good swimmers and have good balance in water, on land or in trees.

The species has now been reintroduced to a second mainland site in Kahurangi National Park. As he grew older, his interest in rare birds deepened. Over the years, Orbell plotted them all out on a map of Fiordland, and he discovered a pattern: all of the captures and sightings had occurred below the bushline, and in years of heavy snowfall.

No one had searched for takahe on the tussocky tops, and that is where, he deduced, the bird might still be hiding. The back and inner wings are teal and green, becoming olive-green at the tail, which is white underneath.

Young stay with parents until just before the next breeding season, or stay for a second year. Unusual cases of breeding trios or greater two females laying have been observed. Pairs defend their breeding territory by calling, or fighting if necessary, returning to the same areas each year.

Sedges Uncinia spp, Carex coriacea , rushes Juncus spp and Aciphylla spp are sometimes taken. Smaller grasses are grazed from the tips down, this being the staple on islands and lowland reserves. When available, grass seeds are stripped from the stem while still attached. In Fiordland winter forest habitat, alternative carbohydrate is found by grubbing starchy rhizomes of a fern Hypolepis millefolium and the rhizomes of the sedge Carex coriacea. In other sites the diet does not vary as much seasonally - pasture grasses are available all year round.

Grueber, C. Are introduced takahe populations on offshore islands at carrying capacity? Implications for genetic management. New Zealand Journal of Ecology 36 : Hegg, D. Demography of takahe Porphyrio hochstetteri in Fiordland: environmental factors and management affect survival and breeding success. Lee, W. Long-term effects of defoliation: incomplete recovery of a New Zealandalpine tussock grass, Chionochloa pallens , after 20 years.

Journal of Applied Ecology 37 : Maxwell, J. Fiordland takahe: population trends, dynamics and problems. Pp in Lee, W. University of Otago Press, Dunedin. Miskelly, C. Conservation translocations of New Zealand birds, Notornis 60 : Robertson, H. A; Baird, K. Conservation status of New Zealand birds, New Zealand Threat Classification Series Wellington, Department of Conservation. Trewick, S. Origins and prehistoric ecology of takahe based on morphometric, molecular and fossil data.

In Miskelly, C.