Brown kiwis have many introduced predators, although they had few predators before dogs, pigs, cats, brush-tailed possums, and stoats were introduced to New Zealand. Dogs, pigs and cats tend to feed on adult birds. Stoats and cats feed on the young, and possums and stoats destroy kiwi eggs.
Known Predators:
Anti-predator Adaptations: cryptic
Brown kiwis are members of the flightless ratite group (Struthioniformes). They are unique in their small size and adaptations to forest floor life. These birds are roughly the size of a chicken, with the female being slightly larger. They range in size from 45 to 54 cm long, and weigh from 2.8 to 3.5 kg. They are brownish grey in color with long, soft feathers that look and feel very fur-like. Their skin is tough and they have whiskers at the base of their bill used for touch. This is especially important for these birds because they have small eyes and poor vision. These birds do not have a tail and their 5 cm long wings prevent them from flying. Brown kiwis have powerful legs and can run quickly. The nostrils are at the end of their long bills and they have a keen sense of smell. The birds thrust their bill into the ground, gather the food, and beat the prey on the ground before they consume it. Other characteristics include heavy bone marrow, a body temperature lower than most other birds, and underdeveloped pectoral muscles. Brown kiwis have body temperatures of 38 degrees Celsius.
Range mass: 2.8 to 3.5 kg.
Range length: 45 to 54 cm.
Other Physical Features: endothermic ; homoiothermic; bilateral symmetry
Sexual Dimorphism: sexes alike; female larger
Average basal metabolic rate: 4.029 W.
The expected lifespan of brown kiwis after their first twelve months of their life is approximately 20 years in the wild. When in captivity, these birds usually live to be 30 years old, but some have lived up to 40 years.
Average lifespan
Status: wild: 20 years.
Range lifespan
Status: captivity: 40 (high) years.
Average lifespan
Status: wild: 20 years.
Average lifespan
Status: captivity: 30 years.
Average lifespan
Status: captivity: 35.0 years.
Brown kiwis live in subtropical and temperate forests and grasslands. They prefer to live in large, dark forest areas, which allow camouflage for the birds as they sleep during the day. In undisturbed habitats, kiwis create burrows under stones, banks of streams, or in soft flat open ground. In disturbed areas, these birds have had to adapt to human presence by establishing burrows in rough farmland under logs and shrubs.
Range elevation: 0 to 1,200 m.
Habitat Regions: temperate ; terrestrial
Terrestrial Biomes: savanna or grassland ; forest ; scrub forest
Other Habitat Features: agricultural
Apteryx australis, commonly known as brown kiwis, is located in the Australian biogeographic region. They are endemic to New Zealand, and reside on North Island (in Northland and Taranaki), South island (in Fiordland and Westland), and Stewart Island.
Apteryx australis is considered by some authors to be made up of two, distinct species, corresponding to the previously recognized subspecies A. australis mantelli - now A. mantelli, and A. australis australis and A. australis lawryi - both retained within A. australis. North Island brown kiwis (A. mantelli) are the most common kind of kiwi, found only on the North Island of New Zealand. Apteryx australis includes populations on Stewart Island (A. a. lawryi) and South Island (A. a. australis), including populations in the Haast range and the fiordlands. Populations in the Haast range (Haast tokoekas) may represent a distinct species as well.
The population of brown kiwis found in Okarito forests on the western coast of the South Island was recently recognized as a distinct species, Apteryx rowi, Okarito brown kiwis or rowis. It is thought that this species is made up of only 200 individuals currently.
Biogeographic Regions: australian (Native )
Other Geographic Terms: island endemic
The government of New Zealand has declared that if avian flu threatens New Zealand, every kiwi will be vaccinated due to the alarming decrease of kiwis.
Although they are currently only found in New Zealand, fossil evidence has shown ancestors of brown kiwis occurred in the North Hemisphere in the Paleocene and Eocene, 40-70 million years ago.
Brown kiwis communicate through a cry, which sounds like a prolonged whistle slightly ascending and descending. Males make a mournful shriek, "kee-wee," and females have a low hoarse cry. Chicks tend to make a clicking sound. The cry indicates their presence at night, and helps in finding mates. They also congregate in companies from six to twelve. To hear the cry of brown kiwis, click here: http://www.nzbirds.com/birds/sound/brownkiwi2.wav
Kiwis are unusual among birds in having a keen sense of smell. They have an enlarged olfactory bulb.
Communication Channels: acoustic
Perception Channels: visual ; tactile ; acoustic ; chemical
Brown kiwis are considered vulnerable by the IUCN. Currently, there are an estimated 27,000 brown kiwis. The primary threat to these birds is predation by introduced mammals. Populations seem to be declining.
US Migratory Bird Act: no special status
US Federal List: no special status
CITES: no special status
IUCN Red List of Threatened Species: vulnerable
There are no known adverse affects of brown kiwis on humans.
Initially hunted to make cloaks and for food, kiwis, including brown kiwis, are the national symbol of New Zealand. Much pride is taken by displaying the kiwi on things such as the national currency, sports uniforms, road signs and mascots.
Positive Impacts: body parts are source of valuable material; ecotourism ; research and education
Brown kiwis are important predators of invertebrates and may disperse seeds through their fruit eating.
Brown kiwis are carnivorous, they feed mainly on soil and aquatic invertebrates such as worms, insects, crayfish, amphibians, and eels. They also eat fruit. At night, these birds use their long bills to dig deep into the ground to find creatures living on the ground. After they have caught something, they use their bills to beat the creature on the ground, or on stones to kill it before eating. Cone-shape holes left in the ground after hunting are easy ways to discover their occurrence in an area.
Animal Foods: amphibians; fish; insects; terrestrial non-insect arthropods; mollusks; terrestrial worms; aquatic crustaceans
Plant Foods: fruit
Primary Diet: carnivore (Insectivore , Eats non-insect arthropods, Vermivore)
Brown kiwis meet in nesting burrows every few days and call to each other at night to begin mating. This ritual occurs between March and June. The relationship is volatile and physical with the females primarily being the dominant one. They are monogamous unless a “better” mate comes along.
Mating System: monogamous
Brown kiwis breed throughout the year but only lay one egg at a time. A second egg might be laid four to six weeks after the first one. The eggs are unique because of their size relative to the adult bird's mass. Brown kiwi eggs are one-third of the female's mass, making them the largest eggs (relative to mass) of any bird. Incubation period lasts up to eleven weeks and the chicks are ready to leave the nest in approximately six to ten days. Females reach sexual maturity on average between the ages of three and five. Males reach this sexual maturity in approximately 18 months.
Breeding interval: Brown kiwis can reproduce as often as every 4 to 6 weeks. However, the massive energy investment that each female makes into any single egg means that she will not often lay eggs that frequently.
Breeding season: Brown kiwis breed throughout the year.
Range eggs per season: 1 to 1.
Average time to hatching: 11 weeks.
Range fledging age: 6 to 10 days.
Average age at sexual or reproductive maturity (female): 3- 5 years.
Average age at sexual or reproductive maturity (male): 18 months months.
Key Reproductive Features: iteroparous ; year-round breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; oviparous
Average birth mass: 325 g.
Average time to hatching: 75 days.
Average eggs per season: 1.
Female brown kiwis dig out the nest and deposit the kiwi eggs, which are smooth and are either ivory or light green in color. After the eggs are laid, males take over incubation and nest maintenance until the eggs hatch. During this time males lose one-third of their weight. After hatching, the chicks do not rely on parents for food. They survive from the copious amount of yolk in their belly. Kiwi chicks venture out of the burrow soon after hatching, although there have been reports of chicks being near their parents for up to a year. Because kiwi chicks are slow, small (weighting only 275 grams and being five inches), and unable to respond to predators, few survive to twelve months old. After that time, they reach a size that enables them to escape most predators.
Parental Investment: precocial ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Male)
The southern brown kiwi, tokoeka, or common kiwi[3] (Apteryx australis) is a species of kiwi from South Island, New Zealand. Until 2000 it was considered conspecific with the North Island brown kiwi, and still is by some authorities.
Apteryx australis is based on Greek and Latin. Apteryx means "A-" without "pterux" wings, and "australis" from "auster" the south wind, and "-alis" relating to.[6] The southern brown kiwi belongs to the kiwi family and it is a ratite, and a member of the order Apterygiformes. Like all ratites, its sternum has no keel, it is flightless, and it has a distinctive palate.[3]
The holotype specimen of Apteryx australis Shaw (Nat. Miscell., 24,1813, pl1057) is held in the collections of National Museums Liverpool at World Museum, with accession number NML-VZ D180. The specimen was collected by Captain Barclay at Dusky Sound, South Island, New Zealand and came to the Liverpool national collection via the 13th Earl of Derby's collection which was bequeathed to the people of Liverpool.
The southern brown kiwi is divided into two subspecies, with some conservationists arguing for a third:
It has no preen gland, and its feathers have no aftershafts and no barbules. There are large vibrissae around its gape, and it has no tail, only a pygostyle. It has a length of 45 to 55 cm (18–22 in) and the female weighs 2.1 to 3.9 kg (4.6–8.6 lb) and the male weighs 1.6 to 2.8 kg (3.5–6.2 lb). Its bill is long and slender with a slight down-curve. Like other kiwis it is nocturnal. The colour of its plumage is rufous with some streaking.[3]
Southern brown kiwi communicate vocally to aid in defending their territory. They will also sing duets with each other, with the male shrill "kee-wee" or "kee-kee" and the females hoarse " kurr kurr".[7] Males are more vocal and they both call in an upright position with their legs stretched out and their bill pointing up.[3]
The southern brown kiwi has a long slender bill with lateral nostrils at the tip, which helps give them their keen sense of smell. They utilise this, more than sight and sound, to forage in dirt for invertebrates, including earthworms, beetle larvae, snails, crayfish,[9] spiders, centipedes, and orthoptera, as well as eels and amphibians.[10] Its gizzard is weak, and underutilised due to the lack of plant matter. Its caeca are long and narrow and aid in digestion.[3]
The southern brown kiwi, like all kiwi, has two functioning ovaries, however only the left oviduct functions, allowing eggs from both ovaries to pass through. It is a monogamous species and once paired up, they will defend their territories with warning calls. The size of their territory is between 4.9 and 43 hectares (12 and 106 acres). Nests are made in burrows, or sheltered beneath thick vegetation. The female lays 1–2 eggs, typically just 1, which the male incubates for 90 days. After a few days the chick will exit the nest and feed on its own, although it may stay around parents for a year. When not incubating eggs, they roost alone in sheltered places at ground level.[3]
Southern brown kiwi live in the South Island and Stewart Island. On the mainland (South Island) they live in Fiordland and Westland. Their range is temperate and sub-tropical forests, grassland, and shrubland, the denser the better.[3] They are widespread throughout Stewart Island where they also live on the sand dunes.[8]
In 2000, after being recognised by IUCN, they were placed in the Vulnerable status group.[2] They have an occurrence range of 9,800 km2 (3,800 sq mi) and population of 27,000 was estimated in 1996.[8] Brush-tailed possums, Trichosurus vulpecula, and stoats, Mustela erminea, will eat the eggs, while stoats and cats will eat chicks and juveniles. Adults are also under threat as dogs, ferrets, and brush-tailed possums, attack them and the juveniles. The Stewart Island population is stable due to the lack of these predators,[2] however stoats may have colonised the island in 2000.[8]
In 2018 a drought caused a poor breeding season for Haast tokoeka and killed three chicks; six were airlifted to Orokonui Ecosanctuary near Dunedin, and then on to a "creche" on Rona Island in Lake Manapouri, Fiordland.[12]
The southern brown kiwi, tokoeka, or common kiwi (Apteryx australis) is a species of kiwi from South Island, New Zealand. Until 2000 it was considered conspecific with the North Island brown kiwi, and still is by some authorities.
