The kiwi is a one-off evolutionary design, holding all sorts of biological records. New Zealand's ancient isolation and lack of mammals allowed it to occupy a habitat and lifestyle that everywhere else in the world would be occupied by a mammal.

Whereas birds traditionally depend on sight, the kiwi is one of the few birds with a highly developed sense of smell. You can sometimes hear them sniffing around in the dark. Alarm them during the day and they will run off. Then, at a distance, just like a wolf or other mammal, they'll stick their bill (nose) in the air, sniffing to see if they are safe from pursuit.

Other reasons the kiwi could pass for a mammal is its loose, hair-like feathers, its long whiskers, the fact it can't fly and that it burrows in the ground.

Other kiwi curiosities include:

• Being the only known bird to have external nostrils at the end of its bill. It literally sniffs out its food a bill-length below the surface.

• It's huge eggs. The kiwi has one of the largest egg-to-body weight ratio of any bird. The mature egg averages 20% of the female's body weight. Compare that to 2% for an ostrich!

• Being the smallest living member of the ratite family (which includes ostriches and emus).

• They live in pairs as monogamous couples for most, if not all of their lives.

• Sex role reversal: The female is bigger and dominates the male.

• In some varieties, the male does most of the incubating of the eggs.

• The eggs take an exceedingly long time to hatch up to 80 days.

• Kiwi can live to be 40 years old
• Whiskers for feeling in the dark
• Tiny wings the kiwi didn't  need to fly when there were no predators in New Zealand
• Nostrils at tip of beak for sniffing out worms and spiders to eat
• Eyes which are good for seeing in the dark
• A female kiwi gives birth to an egg 20% its own body weight
• Long beak to probe in the soft earth
• Feathers, rough and shaggy no use for flying
• Powerful legs for running, kicking and burrowing
• Razor sharp claws
• Kiwi are endemic to New Zealand

Kiwi Diet

There are few surprises in the kiwi diet. It's mostly earthworms, spiders, fallen fruits and seeds, larvae of beetles and cicada and a mixture of forest invertebrates. But they will also take large food items like freshwater crays and even frogs. In captivity, kiwi have fished eels out of a pond, subdued them with a few thuds and eaten them.

Common Kiwi Myths

Kiwi experts are keen to dispel myths surrounding the kiwi particularly that they are half-blind and bumbling.

Here are a few common ones:

Myth: "Kiwi fight with their beaks."

To use their beaks to fight would be like head-butting someone with your nose.

At the end of the beak are the kiwi's external nostrils. Finely tuned and capable of detecting a few parts per million of scent, the beak, when probing the ground, can detect worms and other food.

Myth: "Kiwi are cute, gentle little creatures."

They are actually super-strong and often extremely bad tempered. The adults can look after themselves using their razor sharp claws as weapons. A couple of slashes can quickly draw blood as conservations have often found when putting their hands down kiwi burrows.

Because they are so aggressive, DOC staff can attract them simply by imitating their call. Incensed that another kiwi is on their turf, the response is instant and dramatic:

"It's amazing to hear them coming to kick the intruder out. They sound like a deer charging, almost exploding, through the dark. Standing there, it's quite intimidating. I guess it's part of the threat display."

"Pete" is a Great Spotted Kiwi in West Northland. "We've just got to walk into his territory and he comes catapulting in for a hit-and-run. He belts you in the leg and then runs off into the undergrowth. I think he views us as super-big kiwi. He's probably given some trampers a helluva scare."

Myth: "Kiwi are a bit thick."

According to Conservation Officers who know them best, they are capable of learning quickly and altering behaviour in the light of experience.

Myth: "Kiwi move slowly."

Superbly adapted to their natural habitat, the kiwi is extremely agile and quick moving. A kiwi can cover his territory possibly the size of 60 football fields in a night. This might take in three valley streams and all sorts of obstacles.

Myth: "Kiwi and half-blind."

The notion of their being half-blind probably stems from their being nocturnal and having small eyes. In fact, as Conservation Officers can testify, if you chase them at night, they can run very fast, swerving around trees and expertly navigating the undergrowth. Similarly, they are unfazed by daylight.

Kiwi -- Six Unique Varieties

There are six identified varieties of kiwi.

The Little Spotted Kiwi

The smallest (about the size of a bantam) and most endangered species, the "Little Spots" have a very mellow, often docile nature. They have suffered terrible that the hands of possums, stoats, cats and larger predators.

Now extinct on mainland New Zealand, the largest remaining population is on Kapiti Island where 1000 birds occupy some 1900 ha of mixed forest, scrub and grassland. Sensitive management by DoC and the Maori Trustees of private land on Kapiti are ensuring that cats, dogs and other kiwi predators don't reach the island.

The Great Spotted Kiwi

The rugged mountaineer of the kiwi found primarily in the high, often harsh hill country the Great Spotted has forged a strange deal with evolution. The same harsh environment that makes it struggle from one day to the next also makes it tough going for the pigs, dogs and stoats that would otherwise be keen to pursue it.

Big bold and handsome, it is found only in the South Island, mainly in North West Nelson, Central Westland and Eastern Canterbury.

The North Island Brown Kiwi

Bug noses and short tempers is one way to sum up the Brown Kiwi. They are little toughies ... and have to be to survive against humans, introduced predators and the natural challenges of their often harsh bush existence.

The North Island Brown Kiwi is found only in the upper two-thirds of the North Island. They are widespread in Northland in a diverse range of vegetation types including exotic forests and rough farm land.

Okarito Brown Kiwi

In one sense, the new kid on the block. It was only in 1993 that the Okarito Brown, living in lowland forest just north of Franz Josef was identified as a distinct variety of kiwi. Tell-tale signs are its slightly greyish plumage sometimes accompanied by white facial feathers.

Southern Tokoeka

Squat and round and bigger than their northern Brown Kiwi cousins, they can grow to almost the same size as Great Spotted Kiwi. The Southern Tokoeka are found in Fiordland and on Stewart Island. They are the most communal of the somewhat reclusive kiwi.

Haast Tokoeka

The Haast Tokoeka, found in the rugged mountains behind Haast, was also identified as a distant variety of Kiwi in 1993. They spend their summers in the high subalpine tussock grasslands but probably retreat to the lowland forests in winter.