How about a big post about the various Kiwi species?
Everything is from Wikipedia (except the picture of the Okarito Kiwi). This is just what I found interesting.
General info about Kiwis:
Kiwi are flightless birds endemic to New Zealand, in the genus
Apteryx and family Apterygidae. At around the size of a domestic chicken, kiwi are by far the smallest living ratites and lay the largest egg in relation to their body size of any species of bird in the world. There are five recognised species, two of which are currently vulnerable, one of which is endangered, and one of which is critically endangered. All species have been adversely affected by historic deforestation but currently large areas of their forest habitat are well protected in reserves and national parks. At present, the greatest threat to their survival is predation by invasive mammalian predators.
Their adaptation to a terrestrial life is extensive: like all ratites they have no keel on the breastbone to anchor wing muscles, and barely any wings. The vestiges are so small that they are invisible under the bristly, hair-like, two-branched feathers. While most adult birds have bones with hollow insides to minimise weight and make flight practicable, kiwi have marrow, like mammals and the young of other birds. With no constraints on weight due to flight requirements, Brown Kiwi females carry and lay a single egg which may weigh as much as 450 g (16 oz). Like most other ratites, they have no preen gland. Their bill is long, pliable and sensitive to touch, and their eyes have a reduced pecten. Their feathers lack barbules, and aftershafts, and they have large vibrissae around the gape. They have 13 flight feathers, no tail, just a small pygostyle.
Kiwi are shy and usually nocturnal. Their mostly nocturnal habits may be a result of habitat intrusion by predators, including humans. In areas of New Zealand where introduced predators have been removed, such as sanctuaries, kiwi are often seen in daylight.
(Teeny tiny picture, but it was all I could find.)
The Okarito Kiwi (
Apteryx rowi) also known as the Rowi or Okarito Brown Kiwi, is a member of the Kiwi family Apterygidae, described as new to science in 2003. The species is part of the Brown Kiwi complex, and is morphologically very similar to other members of that complex. It is found in a restricted area of the Okarito forest on the West Coast of New Zealand's South Island, and has a population of about only 300 birds. Some Okarito Brown Kiwis may live up to 100 years.
The Great Spotted Kiwi, Great Gray Kiwi, or Roroa (
Apteryx haastii). As a member of the Ratites, it is flightless. It is the largest of the kiwi. The rugged topography and harsh climate of the high altitude, alpine, part of its habitat render it inhospitable to a number of introduced mammalian predators, which include dogs, ferrets, cats and stoats. Because of this, populations of this species have been less seriously affected by the predations of these invasive species compared to other Kiwi. Nonetheless, there has been a 43% decline in population in the past 45 years, due to these predators and habitat destruction. This has led it to be classified as vulnerable. There are less than 16,000 Great Spotted Kiwis in total, almost all in the more mountainous parts of northwest Nelson, the northwest coast, and the Southern Alps.
The Little Spotted Kiwi or Little Gray Kiwi,
Apteryx owenii, a small species of kiwi originally from New Zealand's South Island (they used to live near Marlborough and where Tokoeka currently live). Around 1890 to 1910 a population of them was trans-located to Kapiti Island for conservation purposes. Little Spotted Kiwis are the smallest species of kiwi, at about 0.9–1.9 kg (2.0–4.2 lb), about the size of a bantam.
As the smallest species of kiwi, the Little Spotted Kiwi would be very vulnerable to the main kiwi predators like cats, dogs, and stoats, however the Little Spotted Kiwi is now restricted to several off-shore island reserves (mainly Kapiti Island). The Little Spotted Kiwi's conservation status is listed as 'Range Restricted' (by 'Save The Kiwi'), with a growing population. Formerly classified as Vulnerable by the IUCN, it was suspected to be more numerous than generally assumed. Following the evaluation of its population size, this was found to be correct, and it is consequently downlisted to Near Threatened status in 2008 as, although not rare, its small range puts it at risk.
The Southern Brown Kiwi, Tokoeka, or Common kiwi,
Apteryx australis. Until 2000 it was considered conspecific with the North Island Brown Kiwi, and still is by some authorities.
Southern Brown Kiwi communicate vocally to aid in defending their territory. They will also sing duets with each other, with the female shrill "kee-wee" or "kee-kee" and the males hoarse " kurr kurr". Males are more vocal and they both call in an upright position with their legs stretched out and their bill pointing up.
The North Island Brown Kiwi (
Apteryx mantelli;
Apteryx australis or
Apteryx bulleri as before 2000, still used in some sources), is a species of kiwi that is widespread in the northern two-thirds of the North Island of New Zealand and, with about 35000 remaining, is the most common kiwi.
Well, they're in the same area of the globe, right..? 
