Apteryx australis (Brown Kiwi)
Description: Small, flightless birds with rudimentary wings, no tails, and shortish stout legs. The head is comparatively small, the neck is long and strong. Kiwis are pear-shaped with very robust legs and feet. The wings have a claw at the tip and they are normally concealed by the rest of the body plumage.
Their bill is long and flexible with a slightly down turned tip. The upper mandible is slightly longer than the lower. The nostrils are at the tip of the beak, they are small and allow the birds to smell prey in leaf-litter and soil. By blowing air through a special valve in the bill, they can clear impuraties from their nostrils.
The tongue is horny and pointed and the base of the bill has a few bristles, that are actually modified hairs.
The legs are strong and set quite far appart, this gives them a rather awkward, rolling gait. The feet have four toes, three fore and one small hind toe. Each toe ends with a strong claw.
Adult
Size: 50-65cm total length. Male beak: 110-155mm, female beak: 130-205mm.
Weight: Male: 1440-3060g, female: 2060-3850g.
Senses: Quite remarkably kiwis are quite good swimmers. They have no problem either wading or swimming across streams and shallow pools.
Habitat: Subtropical to temperate forests and shrublands, especially wet forests with hardwoods. Also found in man-made habitats, such as farmland.
Range: Pairs hold ranges together, they dig out burrows together on their range and usually rest together. In the morning they often leave their burrow seperately and forage appart during the day, meeting up again to sleep. Unlike most other bird species they mark their territory with their droppings, which carry a strong odour.
Pairs are so attached to their territory that they will remain there even after it has suffered deforestation. They will remain until they are close to starvation.
Distribution: New Zealand, also on North, South and Stewart Islands.
Status: Not globally threatened.
Their range has shrunk since the European settlers arrived. Introduced predators kill young and adult birds, as well as taking eggs. These include cats, dogs, mustelids and feral pigs.
Daily Rhythm: Nocturnal. They generally emerge about 15-90 minuets after sunset. After this they remain active until about dawn.
During the day they rest in burrows that they dig out themselves, and which can measure between 20-200cm in length and a width of about 9-15cm, or in natural hollows; such as beneth fallen tree trunks, between roots, or in steep sand-banks. They spend most of their time in the burrow sleeping, although they will wake up occasionally to preen, defecate, stretch or shake damp from their feathers, if the weather is wet.
Voice: They produce a loud snuffling noise when they expell impurities from the nostrils.
Enemies: Eggs suffer heavy predation, Wekas have been known to eat eggs while the male bird is sitting.
Introduced mammals, such as cats, dogs, mustelids and pigs, often kill immature birds and adults.
Prey: Mostly invertebrates (especially insects, such as bugs and beetle larvae, also worms and spiders), also a small proportion of fruit, seeds and leaves.
Food and Feeding: They search for food on the ground, usually smelling their way through the leaf-litter, pushing their bill into the ground when they smell prey and levering it out with a rocking motion or the head.
Grouping: They live in pairs and spend their lives together.
Breeding: Laying June-February, mainly in August-September. Pairs are monogamous and they hold home-ranges all year round. If a mate dies the other animal may seek a new mate.
The courtship has few visual displays, and the displays seem to appeal more to the senses of smell and hearing. During courtship the birds will chase one another, jump, hiss and grunt. Males call and female answear and then they chase one another round in circles before copulating. Copulation is preceeded by the male gently tapping the female on the back of her neck, when she responds by bending over, the male climbs onto her back, leaning on his tarsi he keeps his balance by holding onto the female feathers, he grunts troughout copulation.
Gestation: The amle incubates for about 75-84 days.
Litter Size: 1-3 eggs per clutch.
Young Description: The eggs are large, 115-137 x 70-83mm, with an average weight of 430g, this is 14-20% of the females prelaying body weight.
The chicks are covered with a softer version of the adults plumage. Chciks have an eggsack attached to their stomach, they can feed of their for about 10 days.
Juveniles are similar to their parents but smaller.
Nest: They nest in burrows, which they excavate themsleves, or in natural hollows.
They always prefer to use a burrow that they have excavated themselves. They will not use one of their burrows to breed in until it is several months old, sometimes they wait years. This gives the surrounding vegetation time to grow back and conceal the entrance. Each burrow has one entrance that is about 9-15cm wide and the burrow may be anything from 20-200cm long.
The male waits until the eggs are 2 weeks from hatching before he starts to make the nest. He usually brings plant matter, especially lichens and grasses. When the pair lay a second clutch or a replacement clutch, they will usually use a different nest site.
Young Care: The female lays the eggs and then leaves them to the males care. She remains in the surrounding area, sleeping in a burrow nearby. She will help the male to brood the young once they have hatched. The male usually begins incubating the eggs when the female leaves the burrow, however he may not begin for about 14 days and during the first 20-30 days he may incubate intermittently.
The male will leave the burrow to eat and defecate every night, usually spending about 4-5 hours away from the eggs, though they have been known to leave them for up to 20 hours. When he leaves the burrow he throws sticks and leaves over the entrance, covering it.
The eggs hatch over a 2-3 day period, with a gap of 5-15 days between each egg. The chicks kick their way through the shell as they lack an egg tooth.
They can stand up after 4 days and are able to walk in 5, at this age they start to leave the burrow, mainly at night, often leaving before the adult and returning after.
The young leave the nest nightly to feed themselves after just 5-6 days. The male continues to brrod them through the day and part of the night for about 2-3 weeks, sometimes the female helps.
They become independent at 14-20 days and are fully grown at 18-20 months. Even though the young are independent they live in the adults range, roosting apart from the adults. They have been knwon to live on their parents territory for up to 1-3 years.
Sexual Maturity: 2 years for females and 14 months for males.
Longevity: The oldest animal recorded was 35 years old.
Geographical Variations:
Apteryx australis mantelli
Distribution: North Island.
Description: Coat: More heavily streaked.
Apteryx australis australis
Distribution: South Island.
Apteryx australis lawryi
Distribution: Stewart Island.
Description: Longer billed.
Apteryx australis lawryi Adult
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