Why takahe endangered

Usually only one chick out of each clutch of eggs will survive to become old enough to look after itself. They will pull out feathers, bite, hold on and kick each other with their feet. The males will stand tall and lift their wings and back up. It has territories in the grassland until the arrival of snow, when it moves to the forest or scrub.

Small numbers have also been successfully moved to four predator-free offshore islands, Tiritiri Matangi, Kapiti, Maud and Mana, where they can be viewed by the public. The forest areas were once their favoured location, and it is believed that the forests were the original homes of the bird after their migration to New Zealand several million years ago.

The lack of predators at the time and the ground feeding nature of the bird resulted in evolution causing the flightless nature of the bird today. People tried to get rid of rats, which had become the Takahe's main predator, by introducing weasels, but the weasels just ate more Takahe's as well as baby Takahe's.

By , the population had reduced to a low of birds. This rapid decline occurred during the s when deer became established throughout Fordland. Research has shown that deer, more than any other pest, have had an effect on the birds' nutrition contributing to chick loss and habitat.

Following deer control in the Murchison Mountains, the species has recovered slightly. Even so, only about birds remain in Fordland. Just before they hatch the scientists play adult calls to the egg. An ambitious conservation program was then put in place in the 80's.

New Zealand is now at the forefront of conservation for this iconic species. It is technically impossible to prevent intrusion of land predators in the original habitat as well as to control competition for food by other species. Despite a strict monitoring, the original population of individuals has now stabilized around individuals today. This shows how difficult the conservation of a vulnerable species is even when it is considered as a priority.

In order to increase the chances of survival, smaller populations were relocated to offshore islands with a strict control of land mammals. Captive populations also exist and are deemed necessary to ensure the long term survival of the species.

As recently as in , an increase in the stoats Mustela erminea population had a strong toll on the bird, halving the wild population in a few months time only[1]. Stoats were introduced by Europeans in New Zealand to control mice populations at the end of the 19th century. Introduced European deers Cervus elaphus have been competed with the bird for food to the point that culling programs have been put in place to control the mammal population. I was raised in a family with a long tradition of interest in biology and medicine, especially on my father's side.

From a very young age, I was encouraged to observe nature and learnt how rewarding it was. They can run, but they cannot hide. A helicopter-mounted receiver can find them with pinpoint accuracy. I had already seen this bird sleuthing in operation, and its intrusiveness had left me feeling ambivalent about this research. But for science, locating them was not enough. As the helicopter herded the takahe uphill—the rotor blades almost weed-whacking the tips of cliff-side bushes—the researchers strained their eyes to record the colour codes and dutifully tick them off on their clipboards.

Is it black? Scientists are surely dedicated to their work, I thought, watching from the back seat, but what did takahe—acutely aware of aerial predators such as falcons and black-backed gulls—make of this red-and-white monster chasing them up bluffs, roaring like an avalanche and blowing a hurricane?

Had the mission to save the birds become more important than the birds themselves? Was this type of research really necessary? There is no other practical way of finding out. Which would you choose? Maxwell is a bush-wise young biologist with many voluntary stints on other endangered species to her credit. She spends up to four weeks at a time in the Murchisons, tracking the birds on foot. In her spare time she kayaks the Fiordland coast.

In winter. But back in the chopper I knew none of that, and so I continued to ruminate on the narcissistic nature of science. And so we did. Bird after bird, cirque after cirque, valley after valley, ad nauseam. Containers for lost pride. The morning after the storm dawned clear and cold, revealing a fairytale landscape muffled by fresh snow. Other birds appear much more at home. From the air I had seen the purposeful beeline tracks of a brown kiwi, cutting across steep snowfields and following exposed ridges, its claws doubling for crampons, its beak stabbing the snow like an ice-axe.

These mountain clowns are truly at ease here, taking time out from the business of survival to frolic in the snow, rolling about like a pair of puppies, or to examine the colourful gear of human visitors with a systematic curiosity that, given different circumstances, could pass for scientific zeal. Takahe do none of that. Examine a segment of this cable and you will understand why the birds generate so much excreta. The problem is, there is little nourishment in even the juiciest of these tough mountain grasses.

And so, driven by insatiable hunger, the birds feed as if there were no tomorrow. Not only is their main food of poor nutritional quality, but takahe have had to compete for it with much larger and more mobile browsers. The introduced red deer has stripped large swathes of Fiordland of its native vegetation. In the s, red deer started spreading across the land like bushfire, with a similar impact on the forest and alpine flora.

Fortunately for the plants, the price paid for venison was good, and so the infestation soon turned into a kind of game-meat gold rush. Then, with the advent of helicopters and deer farming, attention turned to live capture, with men leaping out of choppers to bulldog fully grown hinds to the ground—a job so inherently dangerous that the life expectancy of a deer wrestler was estimated at about three years.

By the mids, the deer population was finally brought under control. But for takahe it was almost too late. Tussock is slow to recover from heavy browsing—up to 20 years, suggests a recent study—and without food the takahe population began to collapse. By the early s, there were just over takahe left.

There can be little doubt that without the major conservation effort that followed there would not be a wild takahe in Fiordland today. The valleys were topdressed to speed up the recovery of the tussock, and eggs were shuffled between nests to ensure that each pair would bring up a chick, but both actions had little tangible effect. On the inside, the unit resembles a small maternity ward, though you wear sterilised white gumboots instead of slippers.

The chicks almost never see the puppeteers. At about two weeks of age, all the chicks are brought into the brooding unit to be reared by the puppets. When they are seven to nine weeks old, they are switched to pelleted food and moved outside to an hectare enclosure which looks like a free-range poultry farm with an electric fence and a mustelid trapline around its perimeter. Crucial to future survival are lessons on digging up fern rhizomes, a winter staple of which the novitiates seem to have no innate knowledge.

Sometime in October, almost a year after the eggs are collected, the juveniles are released back into the wild—back to stringy tussocks and cold winters. From then on their life will be a continuous test of survival. It is a test that, thanks to the remarkable efforts of the Burwood Bush personnel, the young takahe have latterly been managing to pass rather successfully. Their survival rate—up to 60 per cent—matches that of birds raised in the wild, though it depends on where they are released.

In the mids, the number of Murchison birds was on the increase, and wildlife managers thought it prudent to found another population. They looked long and hard, and in the end decided on the Stuart Mountains—similar in topography, just north and across the Middle Fiord from the Murchisons.

Between and , 58 captive-reared takahe were released into the Stuarts. Almost all of them vanished. The Stuart site was abandoned, and since takahe have been released into the Murchisons again. By the end of , the number of new arrivals will have totalled 86 birds—enough to give a tremendous boost to the population were it not for a string of unusually heavy winters in the early s.

The winters here can indeed be fierce. 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.