Stories

Land of the birds: the amazing evolution of avian life in New Zealand

If any doubt remained about the veracity of evolution, we need only look to the bittersweet story of New Zealand’s birds. It is a land of many natural wonders, but one not so well known outside the country is its unique and incredible avian life.

Kakapo parrot
Kakapo: a flightless, nocturnal parrot

Humans have only inhabited New Zealand for about 700 years; before we arrived and started wreaking our customary havoc and destruction on nature, the country was endowed with extremely special environmental conditions.

The only land mammals to inhabit New Zealand pre-humanity were three species of bat. And let’s face it, bats are pretty bird-like anyway.

The absence of predators and competition meant that birds had freedom to dominate the land. In blissful isolation, they evolved in a way not seen anywhere else on the planet, filling the roles that typically belong to large animals.

When humans turned up, not only did we hunt, but also brought other invasive land mammals with us – dogs, cats, pigs, rats, weasels, and many more – and New Zealand’s biodiversity was forever changed. Many of the country’s extraordinary birds became quickly extinct, and others that survived are now critically endangered.

Today, frantic measures have been implemented to protect and promote this distinctive birdlife. Maybe it’s too late, and future generations will be left with nothing but bones, pictures and fading stories. If so, it will be yet another tragedy of our own making.

Let’s take a look at some of the most remarkable of these winged creatures…

Moa bird

Tallest ever known: the moa

One of the most remarkable specimens of mammal-free New Zealand is the huge, flightless, and sadly extinct moa.

These beasts reached some 3.7 metres in height, making them the tallest birds known to have existed, about a metre taller than ostriches and nearly as tall as giraffes.

Similar to ostriches, the moas were grazers, occupying a role comparable to that of deer or cattle. In some of the nine species of moa, females were about one-and-a-half times the size of males.

But these placid giants made for easy hunting targets. Within 150 years of the first Maori settlers arriving in New Zealand, the population of the moa vanished from 58,000 to zero. Today the only relic are their bones, and a few preserved feathers and egg shells.

In the Operara Basin on the north-west coast of New Zealand’s South Island, it is possible to explore cave systems once trodden by the moa and see preserved bones. We tried to make it there on our roadtrip but unfortunately ran out of time and had to double back towards Christchurch.

Moa’s gigantic predator: Haast’s eagle

The moa did have a hunter to worry about prior to human settlement: the giant Haast’s eagle. Weighing up to 15 kg and boasting a wingspan over 2.5 metres, it was the largest eagle known to have existed. With these clawed predators swooping around, once upon a time New Zealand bore even closer resemblance to Tolkien’s Middle Earth than it does today.

The Haast eagle filled the niche of the large predator, attacking victims at speeds of 50 miles per hour and lacerating with its giant beak. The moa, although fifteen times its weight, was its main prey. In Maori folklore, there are even stories of Haast’s eagle killing humans.

Regrettably for Haast’s eagles, when the last moas dies away, they were starved of prey and soon suffered the same fate.

Today’s icon: the kiwi

Possibly the most celebrated symbol of New Zealand’s unique wildlife is the kiwi. A distant relative of the moa, it is a furry, flightless bird that can live for half a century. With mammal-like characteristics, it has heavy, marrow-filled bones, a low body temperature, and lives in underground burrows.

We spent a brilliant couple of hours at the National Kiwi Centre in Hokitika on the South Island, where we observed two of these adorable things in a protected environment. As they are nocturnal birds they are kept in a dark and controlled area. It is hard to pick them out at first, and photography is forbidden (hence I don’t have a snap to show here) – but once our eyes adjusted, we soon spied one scuttling around almost chicken-like, pecking and foraging away.

Although the kiwi appears to possess a long beak, it is actually the shortest of any bird in the world. This is because a beak is technically measured from the nostrils to the tip, and unlike any other bird, the kiwi’s nostrils are at the tip of the bill rather than the base, enabling it to sense prey moving underground.

Sadly, the kiwi is endangered and without drastic measures may follow the moa and Haast’s eagle into the pages of history. Once numbering over 12 million, now fewer than 100,000 kiwis remain, and they are declining by 2% a year. Unsurprisingly, this is a result of human impact and the threat of land predators.

In the late 19th century, introduced rabbits were an infuriating pest for New Zealand farmers. In an attempt to control the rabbit plague they in turn introduced stoats. Today, rabbits are still the scourge of New Zealand farmers, and the flourishing stoats are the number one killer of baby kiwis.

Without management, only 10% of kiwi chicks survive six months. Once chicks reach a kilogram in weight they can defend themselves against stoats, but face other, more dangerous obstacles.

In adulthood, dogs become the main threat to kiwis. In areas of plentiful kiwi population, dog ownership is strongly discouraged, and dog owners are strongly advised to keep their pets under control at all times, especially at night. A sign at the National Kiwi Centre reads: “When your dog dies, do you really need another one? Think of the kiwi…”

There is some hope, though: while only about 20% of the general kiwi population is under management, in the predator-controlled area of Coromandel their population is doubling every year.

Yellow-eyed penguin

Among the world’s rarest: the yellow-eyed penguin

The only bird I describe in this article that we were lucky enough to see in the wild is the yellow-eyed penguin. With less than 4,000 remaining, it may be the rarest and most endangered penguin on Earth, and it can only be found in New Zealand.

Penguins are usually social creatures that hang around in colonies, but the yellow-eyed brand is different. Its reclusive nature is such that pairs will only mate in complete isolation, out of view of the prying eyes of their peers.

During our two-week road trip of the South Island, we took an early morning cruise on Milford Sound. The timing was impeccable. Shortly after we glided past Mitre Peak, a pair of yellow-eyed penguins splashed out of the water and toddled about on the rocks, just a few metres away from us. (In case you were wondering, they didn’t mate.)

The predicament facing this irresistibly cute bird is all too familiar. Between 2000 and 2017 its population fell by nearly half. The main culprit? You’ve guessed it – humans. Strong evidence suggests that they are frequently getting caught up and drowned in the nets of commercial fishing trawlers.

This is not the only threat; climate change, disease and animal attacks are also contributing to its gradual disappearance, and on the current trend it faces extinction within two or three decades.

My favourite: the kea

Of all the curious and magnificent birds of New Zealand’s past and presence, none captured my imagination more than the world’s only alpine parrot – the kea. Native to the mountains of New Zealand’s South Island, it is one of the most intelligent birds in existence.

Like the kiwi and the yellow-eyed penguin, the kea is fighting to survive, with its wild population estimated between 1,000 and 5,000. Having adapted to the harsh mountainous environment, it has become social and inquisitive in search of novel food sources.

But while many find the kea’s behaviour endearing, it is known to cause all sorts of mischief in its love of human gadgets. It will closely observe, learn, and copy. Here you can see a video of two keas vandalising a police car.

In my favourite story I heard about the kea, a small group of them spent a day watching workmen in the Hooker Valley coming and going from a large storage shed, paying close attention to the manipulation of the door’s lock. Late in the day, the workmen went inside the shed together to put their tools away. The kea swooped in and bolted them all inside!

In another example, some rangers were preparing to demolish a bridge, and had dynamite set up accordingly. But when they pushed the detonation button, nothing happened – some pesky keas had chewed through the cords.

We spent a week in areas populated by the kea, and I was verging on desperate to catch sight of one of the feathery green wonders. Alas, it was not to be. I might, just might, have heard one though.

One cold night near Mount Cook, I was awoken at 2am by a scrabbling sound just outside our tent, very close to my head. It was followed by a curious low calling sound that could only be a bird of some kind. Not wanting to frighten this visitor with a flash light, I stayed wrapped up and listened with amazement as it poked, spoke, and eventually wandered off.

Was this a kea? It very well could have been – the Mount Cook region is one of its most prominent stomping grounds. Alternatively it could have been a kakapo, the kea’s flightless, nocturnal counterpart. Whatever the case, I will always wonder what I would have seen that night if I’d unzipped the tent and gone outside.

You can find out more about the kea and the measures being taken to protect it at www.keaconservation.co.nz.

 

 

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