Kiwis (KEE-weez) are about the size of a chicken. They range in height from 14 to 22 inches (35 to 55 centimeters) and weigh 2.6 to 8.6 pounds (1.2 to 3.9 kilograms). They have brown and black hair-like feathers, no tail, and four toes.
Kiwis are the smallest of a group of birds called ratites, flightless birds that have a flat breastbone rather than a keeled (curved) breastbone like birds of flight. They have a simplified wing bone structure, strong legs, and no feather vanes, the barbs that make up each feather, making it unnecessary to oil the feathers. Consequently, they have no preen gland, which normally contains preening oil.
Kiwis are found in various locations in New Zealand and on nearby islands, including Stewart Island. The North Island brown kiwi is the most widespread, with an estimated 30,000 in the wild.
Most kiwis prefer subtropical and temperate forests, including coniferous and deciduous forests, grassland, scrubland, and farmland. Two varieties live in the higher elevations, the Stewart Island brown kiwi and great spotted kiwi.
Kiwis are primarily insectivores, meaning they eat mainly insects. Their diet includes earthworms, beetles, snails, caterpillars, centipedes, spiders, cockroaches, praying mantises, snails, locusts, crickets, grasshoppers, and insect larvae. They will eat some plant material, such as fallen fruit and berries, but only rarely. Kiwis find most of their food by scent, using the highly sensitive nostrils located at the end of their beak.
BEHAVIOR AND REPRODUCTION
Kiwis are nocturnal, meaning they are most active at night. They live in burrows they dig several weeks before they are used. This allows the regrowth of moss and other vegetation that camouflages (KAM-uh-flajuhs) the burrow. A pair of kiwis can have up to one hundred burrows within their established territory, which is generally 61.75 acres (25 hectares) but can be as much as 120 acres (48 hectares).
Kiwis are shy, night birds with a keen sense of smell. They are monogamous, meaning they mate with only one partner. They pair up for at least two or three breeding seasons and sometimes for life. The female usually digs a nest in the ground where she lays one or two large eggs, weighing about 1 pound (0.45 kilograms) each.
KIWIS AND PEOPLE
The kiwi is the national symbol of New Zealand and an important draw for tourists. Its image is found on New Zealand stamps, coins, and corporate logos, including the now-defunct Kiwi Air. It is used to promote a variety of commercial products.
The IUCN lists the brown kiwi as Endangered, facing a very high risk of extinction, and three kiwi species as Vulnerable, facing a high risk of extinction: the little spotted kiwi, great spotted kiwi, and brown kiwi.
About 1,000 years ago, there were an estimated twelve million kiwis in New Zealand. That number dropped to five million by 1930 due to hunting by humans and animals, such as dogs, cats, and stoats, which are small weasels. As of 2004, there are only about 50,000 to 60,000 kiwis left in the wild and that number is dwindling each year. In 1991, the New Zealand government began a kiwi recovery program that includes establishing kiwi sanctuaries.