Kiwi are flightless birds native to New Zealand. Approximately the size of a domestic chicken, kiwi are the smallest birds in the group that also includes ostriches, emus, rheas and cassowaries. There are five species. All five have been negatively affected by deforestation of their habitat, but they are now well protected in large forest reserves and national parks. Currently the greatest threat to their survival are mammalian predators that include dogs, ferrets and stoats, cats, rats, wild pigs and possums. Fully 95% of kiwi chicks die before 6 months of age. Their vestigial wings are so small as to be invisible under their bristly feathers. Other unique adaptations of kiwi, such as short stout legs, and using their nostrils at the end of their long beaks to detect prey before they see it, make this bird easily recognizable. Kiwi have a highly developed sense of smell, unusual in a bird, and are the only birds with nostrils at the end of their long beaks. Kiwi eggs are the largest in proportion to body size of any bird in the world. Even though the kiwi is about the size of a domestic chicken, it is able to lay eggs that are about six times the size of a chicken's egg! Producing the huge egg places significant stress on the female; for the thirty days it takes to grow the fully developed egg, the female must eat three times her normal amount. Two to three days before the egg is laid there is little space left inside the female for her stomach, so she is forced to fast. These large eggs would have originally been safe given New Zealand's early absence of egg-eating ground predators; today they are often eaten by predators that have been introduced by humans. The five species:   Great Spotted Kiwi The largest species, standing about 45 cm tall, with females weighing about 3.3 kg and males about 2.4 kg. It has grey-brown plumage with lighter bands. The female lays one egg a year, which both parents incubate. The population is estimated at over 20,000, distributed throughout the northern West Coast, and the Southern Alps of the South Island.   Little Spotted Kiwi A small kiwi standing 25 cm (9.8 in) tall, with the female weighing 1.3 kg. She lays one egg, which is incubated by the male. This small, docile kiwi is extinct on the mainland due to predation by pigs and cats, but about 1350 remain on Kapiti Island, and it has been introduced to other predator-free islands, where it appears to be getting established with about 50 on each island.   Okarito Brown Kiwi The Okarito kiwi is slightly smaller than the North Island brown kiwi, with a greyish tinge to its feathers, and sometimes white feathers on its face. Females lay up to three eggs in a season, each one in a different nest! Male and female both incubate the eggs. Distribution is now limited to a small area on the West Coast of the South Island.   Southern Brown Kiwi, or Common Kiwi This species is almost as big as the great spotted kiwi. There are three subspecies, including the Stewart Island southern brown, and the northern and southern Fiordland kiwi, which live in the remote southwest part of South Island. The latter are relatively common, and are nearly 40 cm tall. The third is the southern brown, the rarest, with only about 300 individuals. It lives only in the Southern Alps at an altitude of 1,500 m.   North Island Brown Kiwi This species is native to the North Island. Females stand about 40 cm tall and weigh about 2.8 kg, while the males weigh about 2.2 kg. The plumage is streaky red-brown and spiky. The female usually lays two eggs, which are incubated by the male. The North Island brown has adapted to a wide range of habitats, including non-native forests and some farmland. It is the most common kiwi, with about 35,000 remaining. Hear a female North Island Brown kiwi here The eye of the kiwi is the smallest relative to body mass in all bird species, resulting in the smallest visual field. Some specimens have even been discovered to be blind, showing how little kiwi use their sight; they rely more heavily on their other senses. The kiwi's mostly nocturnal habits may be a result of predators, including humans. Interestingly, in areas of New Zealand where predators have been removed, such as sanctuaries, kiwi are often seen in daylight. Kiwi eat small invertebrates, including grubs and many types of worms. They also may eat seeds, fruit, small crayfish, eels and amphibians. Because their nostrils are located at the end of their long beaks, kiwi can locate insects and worms underground using smell, without actually seeing or feeling them. Once bonded, a male and female kiwi may live their entire lives as a monogamous couple. During the mating season, June to March, the pair call to each other at night, and meet in the nesting burrow every three days. These relationships may last for up to 20 years. Incidentally, the kiwi fruit was named after the bird! Resources Credit: Wikipedia HTML, graphics & design by Bill Willis 2025