The kiwi is the smallest living member of the ratite family, a group of flightless birds which
includes rheas, ostriches, emu and the extinct NZ moa. It lives in burrows in the ground
and is largely nocturnal.
It is the only known bird to have external nostrils at the end of its bill and one of the few to have a highly developed sense of smell. A kiwi literally sniffs out its food.
Kiwis are unique in that they have no tail, and stubby, two inch wings that are usually covered by their coarse, bristly, hair-like feathers. These wings are pretty much useless. .
Thanks to New Zealand's ancient isolation and lack of mammals, the kiwi evolved to occupy a habitat and lifestyle that elsewhere in the world is occupied by a mammal.
It means that in many ways the kiwi is a very unbird-like bird. Its skin is tough as shoe-leather, its feathers are like hair, its bones are heavy, its wings end in a cat-like claw and its body temperature is 38° Celcius, lower than most other birds.
Because they are so aggressive, Department of Conservation staff can attract them simply by imitating their call. Incensed that another kiwi is on their turf, the response can be instant and dramatic. John McLennan (Landcare Research) describes what happens when he imitates the call:
"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 - even for us. I guess it's part of the threat display."
"Pete", a Great Spotted Kiwi in North Westland, is the most aggressive McLennan has crossed paths with. "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 hell-of-a-scare."
For more interesting facts, pictures and everything you might want to know: Kiwi Recovery