Great Spotted Kiwi
Encyclopedia
The Great Spotted Kiwi, Great Gray Kiwi, or Roroa, Apteryx haastii, is a species of kiwi
endemic to the South Island
of New Zealand
. The Great Spotted Kiwi, as a member of the Ratite
s, 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, pig
s and stoats. Because of this, populations of this species have been less seriously affected by the predations of these mammals compared to other species of Kiwi. Nonetheless, there has been a 43% decline in population in the past 45 years, due to the predations of these invasive species and habitat destruction. This has led it to be classified as vulnerable
. There are about 22,000 Great Spotted Kiwis in total, almost all in the more mountainous parts of northwest Nelson
, the northwest coast, and the Southern Alps
. A minority live on islands.
This kiwi is highly aggressive, and pairs will defend their large territories (49 acres) against other kiwi. Great Spotted Kiwi are nocturnal, and will sleep during the day in burrows. At night, they feed on invertebrates and will also eat plants. Great Spotted Kiwi breed between June and March. The egg
is the largest of all birds in proportion to the size of the bird. Chicks take 75 to 85 days to hatch, and after hatching, they are abandoned by their parents.
(Apteryx australis), Okarito Brown Kiwi
(Apteryx rowi), Little Spotted Kiwi
(Apteryx owenii), and North Island Brown Kiwi
(Apteryx mantelli). Great Spotted Kiwis are related closest to the Little Spotted Kiwi. The Kiwi genus
, Apteryx, is endemic to only New Zealand. 44% of the bird species native to New Zealand are endemic. Kiwis are placed in the Ratite
family, which also includes the Emu
, Ostrich
, Rhea
, and Cassowary
. All Ratites are flightless. Kiwi are closely related to the extinct Moa
bird that once inhabited New Zealand.
Before the Great Spotted Kiwi was discovered, several stories circulated about the existence of a large kiwi called the Maori Roaroa. In 1871, two specimens were brought to the Canterbury Museum, where they were identified as a new species and were named after the museum's curator, Dr. Haast.
The Great Spotted Kiwi was first described as Apteryx haastii by Thomas Henry Potts
, in 1872, based on a specimen from Westland
, New Zealand
. It is a monotypic species.
words a "without" or "no", and pteryx, "wing" and haasti is the Latin
form of the last name of Sir Julius von Haast
.
Relationships in the genus Apteryx
. It has a plumage
composed of soft, hair-like feathers, which have no aftershafts. The plumage can range from charcoal gray to light brown. They have large vibrissae
around the gape
, and they have no tail, only a small pygostyle
. The common name of this bird comes from black spots on its feathers. They use their powerful legs and claws for defense against predators like stoats or ferrets. Kiwis are flightless birds, and this is because Kiwis lack hollow bones, lack a keel
to which wing muscles anchor, and have tiny wings. This species also has a low body temperature compared to other birds and are rather fast. They can live for up to fifteen years.
Greater Spotted Kiwis once lived in numerous areas throughout the South Island
, but because of predation
by invasive species
, the remaining kiwi are now restricted to three localities. These kiwi live in higher altitude areas. Populations are present from northwestern Nelson
to the Buller River
, the northwest coast (Hurunui River
to Arthur's Pass
), and the Paparoa Range, as well as within the Lake Rotoiti
Mainland Island. The Southern Alps population is particularly isolated. Great Spotted Kiwis reside in complex, maze-like burrows that they construct. Up to fifty burrows can exist in one bird's territory. They will often move around, staying in a different burrow every day. Bird's Nest Fungus sometimes grows in these burrows. Their habitat ranges in elevation from sea level to 1500 m (4,921.3 ft), but the majority are concentrated in a range from 700 to 1100 m (2,296.6 to 3,608.9 ft) in a subalpine
zone. These kiwis will live in tussock grassland
s, scrubland, pasture
, and forests.
The Great Spotted Kiwi population started declining when European settlers first arrived in New Zealand. Before settlers arrived, about 12 million Great Spotted Kiwis lived in New Zealand. This bird is often preyed upon by invasive pigs, dogs, ferrets and stoats, leading to a 5% chick survival rate. It has more of an advantage than other kiwi species over these predators because it lives in high altitude areas, where the wet upland population thrives. However, there has been a decrease in population of 43% in the past 45 years, and has declined 90% since 1900. Humans have also endangered the species by destroying their habitat
by logging forests and building mines. Previously, humans hunted these kiwis for feathers and food. In 1988, the species was listed as Least Concern species
. It is currently classified by the IUCN
as a vulnerable species
. This kiwi has an occurrence range of 8500 km² (3,281.9 sq mi), and in 2000 an estimated 22,000 adult birds remained. They have been trending down about 5.8% a year. The main threat is from predators is mustelids, brush-tailed possum Trichosurus vulpecula, cats, dogs and pigs The most threatened populations are in the southern areas of the species' range. About 22,000 Great Spotted Kiwis remain. Movements for saving the Kiwi are in place, and sanctuaries for the Great Spotted Kiwi have been made. Thanks to intensive trapping and poisoning efforts the chick survival rate has been raised to about 60% in areas where mammalian pest control is undertaken.
, spiders, caterpillars, slugs and snails on the ground. They will also feed on berries and seeds. To find prey, the Great Spotted Kiwi use their scenting skills or feel vibrations caused by the movement of their prey. To do the latter, a kiwi would stick its beak into the ground, then use its beak to dig into the ground. As they are nocturnal, they do not emerge until thirty minutes after sunset to begin the hunt. Kiwis will also swallow small stones, which aid in digestion.
, which is now extinct.
are made in burrow
s. The breeding season begins in June and ends in March, as this is when food is plentiful. Males reach sexual maturity
at 18 months in captivity, while females are able to lay eggs after three years. In the wild, sexual maturity for both sexes is between ages three and five. Great Spotted Kiwi males chase females around until the females either run off or mate. The pair mates about two to three times during peak activity. The gestation
period is about a month. Females do not eat during this period, as the eggs
will take up a fourth of a kiwi's body mass. The egg is so large because the yolk takes up 65% of the egg. In most bird eggs, the yolk takes up about 35 to 40% of the egg. This makes the kiwi egg the largest in proportion to the body. Females must rely on fat stored from the previous five months to survive. Because of the large size of the egg, gestation is uncomfortable to the female, and they do not move much. To relieve the pain, females soak themselves in puddles when they come out of the burrows by dipping their abdomens into the puddle. The egg-laying season is between August and January.
After the female lays the egg, the male incubates the egg while the female guards the nest. Males only leave the nest for a few hours to hunt, and during this time, the female takes over. It takes 75 to 85 days for the egg to hatch. The baby kiwi takes 2 to 3 days simply to get out of its egg. Kiwi babies are precocial
, and are abandoned by their parents after hatching. After ten days, chicks venture out of the burrow to hunt. Most chicks are killed by predators in the first six months of their life. Great Spotted Kiwis reach full size at year six. Unlike most birds, female Great Spotted Kiwis have two ovaries. Most birds have only one. Great Spotted Kiwis are distinguishable from other kiwi species by the fact that they can only produce one egg a year, as it takes so much energy to produce the massive egg.
Kiwi
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...
endemic to the South Island
South Island
The South Island is the larger of the two major islands of New Zealand, the other being the more populous North Island. It is bordered to the north by Cook Strait, to the west by the Tasman Sea, to the south and east by the Pacific Ocean...
of New Zealand
New Zealand
New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...
. The Great Spotted Kiwi, as a member of the Ratite
Ratite
A ratite is any of a diverse group of large, flightless birds of Gondwanan origin, most of them now extinct. Unlike other flightless birds, the ratites have no keel on their sternum—hence the name from the Latin ratis...
s, is flightless
Flightless bird
Flightless birds are birds which lack the ability to fly, relying instead on their ability to run or swim. They are thought to have evolved from flying ancestors. There are about forty species in existence today, the best known being the ostrich, emu, cassowary, rhea, kiwi, and penguin...
. 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
Invasive species
"Invasive species", or invasive exotics, is a nomenclature term and categorization phrase used for flora and fauna, and for specific restoration-preservation processes in native habitats, with several definitions....
, which include dogs, ferrets, pig
Pig
A pig is any of the animals in the genus Sus, within the Suidae family of even-toed ungulates. Pigs include the domestic pig, its ancestor the wild boar, and several other wild relatives...
s and stoats. Because of this, populations of this species have been less seriously affected by the predations of these mammals compared to other species of Kiwi. Nonetheless, there has been a 43% decline in population in the past 45 years, due to the predations of these invasive species and habitat destruction. This has led it to be classified as vulnerable
Vulnerable species
On 30 January 2010, the IUCN Red List of Threatened Species identified 9694 Vulnerable species, subspecies and varieties, stocks and sub-populations.-References:...
. There are about 22,000 Great Spotted Kiwis in total, almost all in the more mountainous parts of northwest Nelson
Nelson, New Zealand
Nelson is a city on the eastern shores of Tasman Bay, and is the economic and cultural centre of the Nelson-Tasman region. Established in 1841, it is the second oldest settled city in New Zealand and the oldest in the South Island....
, the northwest coast, and the Southern Alps
Southern Alps
The Southern Alps is a mountain range extending along much of the length of New Zealand's South Island, reaching its greatest elevations near the island's western side...
. A minority live on islands.
This kiwi is highly aggressive, and pairs will defend their large territories (49 acres) against other kiwi. Great Spotted Kiwi are nocturnal, and will sleep during the day in burrows. At night, they feed on invertebrates and will also eat plants. Great Spotted Kiwi breed between June and March. The egg
Egg (biology)
An egg is an organic vessel in which an embryo first begins to develop. In most birds, reptiles, insects, molluscs, fish, and monotremes, an egg is the zygote, resulting from fertilization of the ovum, which is expelled from the body and permitted to develop outside the body until the developing...
is the largest of all birds in proportion to the size of the bird. Chicks take 75 to 85 days to hatch, and after hatching, they are abandoned by their parents.
Taxonomy
This large kiwi is one of five species of kiwis residing in New Zealand. The other four are the TokoekaTokoeka
The Southern Brown Kiwi, Tokoeka, or Common kiwi, Apteryx australis, is a species of kiwi from New Zealand's South Island. Until 2000 it was considered conspecific with the North Island Brown Kiwi, and still is by some authorities.-Taxonomy:...
(Apteryx australis), Okarito Brown Kiwi
Okarito Brown Kiwi
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...
(Apteryx rowi), Little Spotted Kiwi
Little Spotted Kiwi
The Little Spotted Kiwi or Little Gray Kiwi, Apteryx owenii, is a small species of kiwi originally from New Zealand's South Island that, around 1890 and 1910 was captured and later released on Kapiti Island...
(Apteryx owenii), and North Island Brown Kiwi
North Island Brown Kiwi
The North Island Brown Kiwi, Apteryx mantelli, Apteryx australis or Apteryx bulleri before 2000 , 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.-Taxonomy:Until 2000, the Brown Kiwi was...
(Apteryx mantelli). Great Spotted Kiwis are related closest to the Little Spotted Kiwi. The Kiwi genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
, Apteryx, is endemic to only New Zealand. 44% of the bird species native to New Zealand are endemic. Kiwis are placed in the Ratite
Ratite
A ratite is any of a diverse group of large, flightless birds of Gondwanan origin, most of them now extinct. Unlike other flightless birds, the ratites have no keel on their sternum—hence the name from the Latin ratis...
family, which also includes the Emu
Emu
The Emu Dromaius novaehollandiae) is the largest bird native to Australia and the only extant member of the genus Dromaius. It is the second-largest extant bird in the world by height, after its ratite relative, the ostrich. There are three subspecies of Emus in Australia...
, Ostrich
Ostrich
The Ostrich is one or two species of large flightless birds native to Africa, the only living member of the genus Struthio. Some analyses indicate that the Somali Ostrich may be better considered a full species apart from the Common Ostrich, but most taxonomists consider it to be a...
, Rhea
Rhea (bird)
The rheas are ratites in the genus Rhea, native to South America. There are two existing species: the Greater or American Rhea and the Lesser or Darwin's Rhea. The genus name was given in 1752 by Paul Möhring and adopted as the English common name. Möhring's reason for choosing this name, from the...
, and Cassowary
Cassowary
The cassowaries are ratites, very large flightless birds in the genus Casuarius native to the tropical forests of New Guinea, nearby islands and northeastern Australia. There are three extant species recognized today...
. All Ratites are flightless. Kiwi are closely related to the extinct Moa
Moa
The moa were eleven species of flightless birds endemic to New Zealand. The two largest species, Dinornis robustus and Dinornis novaezelandiae, reached about in height with neck outstretched, and weighed about ....
bird that once inhabited New Zealand.
Before the Great Spotted Kiwi was discovered, several stories circulated about the existence of a large kiwi called the Maori Roaroa. In 1871, two specimens were brought to the Canterbury Museum, where they were identified as a new species and were named after the museum's curator, Dr. Haast.
The Great Spotted Kiwi was first described as Apteryx haastii by Thomas Henry Potts
Thomas Henry Potts
Thomas Henry Potts was a British-born New Zealand naturalist, ornithologist, entomologist, and botanist....
, in 1872, based on a specimen from Westland
Westland District
Westland District is a territorial authority on the west coast of New Zealand's South Island. Its population is - Government :The Westland District is governed by an elected Council, headed by an elected Mayor. The Mayor is elected at large. The current Mayor is Maureen Pugh. Councillors are...
, New Zealand
New Zealand
New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...
. It is a monotypic species.
Etymology
The genus name, Apteryx, comes from the Ancient GreekAncient Greek
Ancient Greek is the stage of the Greek language in the periods spanning the times c. 9th–6th centuries BC, , c. 5th–4th centuries BC , and the c. 3rd century BC – 6th century AD of ancient Greece and the ancient world; being predated in the 2nd millennium BC by Mycenaean Greek...
words a "without" or "no", and pteryx, "wing" and haasti is the Latin
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...
form of the last name of Sir Julius von Haast
Julius von Haast
Sir Johann Franz "Julius" von Haast was a German geologist. He founded Canterbury Museum at Christchurch.-Biography:...
.
Relationships in the genus Apteryx
Description
Great Spotted Kiwis are the largest of the kiwis; the male is 45 cm (17.7 in) tall, while the female is 50 cm (19.7 in) tall. Bill length ranges from 9 to 12 cm (3.5 to 4.7 in), while weight ranges between 1.2 and 2.6 kg (2.6 and 5.7 lb) for males and 1.5 and 3.3 kg (3.3 and 7.3 lb) for females. The body is pear-shaped, while the head and neck is small with a long slender ivory bill. The Great Spotted Kiwi, along with the other Kiwi species, is the only bird with nostrils at the end of its bill. The eyes are small and do not see well, as it relies mostly on its sense of smell. The legs are short, with three toes per footFoot
The foot is an anatomical structure found in many vertebrates. It is the terminal portion of a limb which bears weight and allows locomotion. In many animals with feet, the foot is a separate organ at the terminal part of the leg made up of one or more segments or bones, generally including claws...
. It has a plumage
Plumage
Plumage refers both to the layer of feathers that cover a bird and the pattern, colour, and arrangement of those feathers. The pattern and colours of plumage vary between species and subspecies and can also vary between different age classes, sexes, and season. Within species there can also be a...
composed of soft, hair-like feathers, which have no aftershafts. The plumage can range from charcoal gray to light brown. They have large vibrissae
Vibrissae
Vibrissae , or whiskers, are specialized hairs usually employed for tactile sensation. The term may also refer to the thick hairs found inside human nostrils, but these have no sensorial function and only operate as an airborne particulate barrier...
around the gape
Gape
In bird anatomy, the gape is the interior of the open mouth of a bird and the gape flange is the region where the two mandibles join together, at the base of the beak...
, and they have no tail, only a small pygostyle
Pygostyle
Pygostyle refers to a number of the final few caudal vertebrae fused into a single ossification, supporting the tail feathers and musculature. In modern birds, the rectrices attach to these....
. The common name of this bird comes from black spots on its feathers. They use their powerful legs and claws for defense against predators like stoats or ferrets. Kiwis are flightless birds, and this is because Kiwis lack hollow bones, lack a keel
Keel (bird)
A keel or carina in bird anatomy is an extension of the sternum which runs axially along the midline of the sternum and extends outward, perpendicular to the plane of the ribs. The keel provides an anchor to which a bird's wing muscles attach, thereby providing adequate leverage for flight...
to which wing muscles anchor, and have tiny wings. This species also has a low body temperature compared to other birds and are rather fast. They can live for up to fifteen years.
Distribution and habitat
South Island
The South Island is the larger of the two major islands of New Zealand, the other being the more populous North Island. It is bordered to the north by Cook Strait, to the west by the Tasman Sea, to the south and east by the Pacific Ocean...
, but because of predation
Predation
In ecology, predation describes a biological interaction where a predator feeds on its prey . Predators may or may not kill their prey prior to feeding on them, but the act of predation always results in the death of its prey and the eventual absorption of the prey's tissue through consumption...
by invasive species
Invasive species
"Invasive species", or invasive exotics, is a nomenclature term and categorization phrase used for flora and fauna, and for specific restoration-preservation processes in native habitats, with several definitions....
, the remaining kiwi are now restricted to three localities. These kiwi live in higher altitude areas. Populations are present from northwestern Nelson
Nelson, New Zealand
Nelson is a city on the eastern shores of Tasman Bay, and is the economic and cultural centre of the Nelson-Tasman region. Established in 1841, it is the second oldest settled city in New Zealand and the oldest in the South Island....
to the Buller River
Buller River
The Buller River is in the South Island of New Zealand. One of the country's longest rivers, it flows for 170 kilometres from Lake Rotoiti through the Buller Gorge and into the Tasman Sea near the town of Westport...
, the northwest coast (Hurunui River
Hurunui River
The Hurunui River is the fourth largest of the four principal rivers in north Canterbury, New Zealand, with a catchment area of 2,670 square kilometres. The river flows from the eastern side of the Southern Alps, to the Pacific Ocean....
to Arthur's Pass
Arthur's Pass
Arthur's Pass is a mountain pass in the Southern Alps of the South Island of New Zealand. It marks part of the boundary between the West Coast and Canterbury regions, 140 km from Christchurch and 95 km from Greymouth. The pass lies in a saddle between the valleys of the Otira River, a...
), and the Paparoa Range, as well as within the Lake Rotoiti
Lake Rotoiti, Tasman
Lake Rotoiti is lake in the Tasman Region of New Zealand. It is a substantial mountain lake within the borders of the Nelson Lakes National Park. The lake is fed by the Travers River, water from it flows into the Buller River. The greatest depth is 82 metres and it is surrounded by beech forest...
Mainland Island. The Southern Alps population is particularly isolated. Great Spotted Kiwis reside in complex, maze-like burrows that they construct. Up to fifty burrows can exist in one bird's territory. They will often move around, staying in a different burrow every day. Bird's Nest Fungus sometimes grows in these burrows. Their habitat ranges in elevation from sea level to 1500 m (4,921.3 ft), but the majority are concentrated in a range from 700 to 1100 m (2,296.6 to 3,608.9 ft) in a subalpine
Subalpine
The subalpine zone is the biotic zone immediately below tree line around the world. Species that occur in this zone depend on the location of the zone on the Earth, for example, Snow Gum in Australia, or Subalpine Larch, Mountain Hemlock and Subalpine Fir in western North America.Trees in the...
zone. These kiwis will live in tussock grassland
Tussock grassland
Tussock grassland is a form of open grassland common in many temperate southern hemisphere regions, notably in New Zealand, but also in Australia, Argentina, some subantarctic islands, and parts of southern and eastern Africa....
s, scrubland, pasture
Pasture
Pasture is land used for grazing. Pasture lands in the narrow sense are enclosed tracts of farmland, grazed by domesticated livestock, such as horses, cattle, sheep or swine. The vegetation of tended pasture, forage, consists mainly of grasses, with an interspersion of legumes and other forbs...
, and forests.
Conservation
| Location | Population | Date | Trend |
|---|---|---|---|
| Buller River Buller River The Buller River is in the South Island of New Zealand. One of the country's longest rivers, it flows for 170 kilometres from Lake Rotoiti through the Buller Gorge and into the Tasman Sea near the town of Westport... to Nelson Nelson, New Zealand Nelson is a city on the eastern shores of Tasman Bay, and is the economic and cultural centre of the Nelson-Tasman region. Established in 1841, it is the second oldest settled city in New Zealand and the oldest in the South Island.... |
Unknown | Declining | |
| Paparoa Range | Unknown | Declining | |
| Arthur's Pass National Park Arthur's Pass National Park Arthur's Pass National Park is located in the South Island of New Zealand.It was established in 1929, becoming the first national park in the South Island and the third in New Zealand. It is bisected by State Highway 73. The road passes through Arthur's Pass village and the mountain pass with the... |
Unknown | Declining | |
| Nelson Lakes National Park Nelson Lakes National Park Nelson Lakes National Park is located in the South Island of New Zealand.It was formed in 1956 and covers some 1,020 km². It is centered at two large lakes, Rotoiti and Rotoroa. The park also includes surrounding valleys and mountain ranges... |
Unknown | 2007 | Introduced |
| Total (South Island South Island The South Island is the larger of the two major islands of New Zealand, the other being the more populous North Island. It is bordered to the north by Cook Strait, to the west by the Tasman Sea, to the south and east by the Pacific Ocean... , New Zealand New Zealand New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga... ) |
16,000 | 2008 | Declining -2% yr |
The Great Spotted Kiwi population started declining when European settlers first arrived in New Zealand. Before settlers arrived, about 12 million Great Spotted Kiwis lived in New Zealand. This bird is often preyed upon by invasive pigs, dogs, ferrets and stoats, leading to a 5% chick survival rate. It has more of an advantage than other kiwi species over these predators because it lives in high altitude areas, where the wet upland population thrives. However, there has been a decrease in population of 43% in the past 45 years, and has declined 90% since 1900. Humans have also endangered the species by destroying their habitat
Habitat destruction
Habitat destruction is the process in which natural habitat is rendered functionally unable to support the species present. In this process, the organisms that previously used the site are displaced or destroyed, reducing biodiversity. Habitat destruction by human activity mainly for the purpose of...
by logging forests and building mines. Previously, humans hunted these kiwis for feathers and food. In 1988, the species was listed as Least Concern species
Least Concern
Least Concern is an IUCN category assigned to extant taxon or lower taxa which have been evaluated but do not qualify for any other category. As such they do not qualify as threatened, Near Threatened, or Conservation Dependent...
. It is currently classified by the IUCN
IUCN Red List
The IUCN Red List of Threatened Species , founded in 1963, is the world's most comprehensive inventory of the global conservation status of biological species. The International Union for Conservation of Nature is the world's main authority on the conservation status of species...
as a vulnerable species
Vulnerable species
On 30 January 2010, the IUCN Red List of Threatened Species identified 9694 Vulnerable species, subspecies and varieties, stocks and sub-populations.-References:...
. This kiwi has an occurrence range of 8500 km² (3,281.9 sq mi), and in 2000 an estimated 22,000 adult birds remained. They have been trending down about 5.8% a year. The main threat is from predators is mustelids, brush-tailed possum Trichosurus vulpecula, cats, dogs and pigs The most threatened populations are in the southern areas of the species' range. About 22,000 Great Spotted Kiwis remain. Movements for saving the Kiwi are in place, and sanctuaries for the Great Spotted Kiwi have been made. Thanks to intensive trapping and poisoning efforts the chick survival rate has been raised to about 60% in areas where mammalian pest control is undertaken.
Behavior
The Great Spotted Kiwi is nocturnal in behavior. If the Kiwis live in an area lacking predators, they will come out in the day. At night, they come out to feed. Like other species of Kiwi, they have a good sense of smell, which is unusual in birds. Males are fiercely territorial. They have bad tempers and will defend their large territories fiercely. At most, four to five Kiwis live in a square kilometer. One pair's territory can be 25 hectares (61.8 acre) in size. It is not known how they defend such a large territory in proportion to their size. They will call, chase, or fight intruders out. Vocalizations of the Great Spotted Kiwi include growls, hisses, and bill snapping. Great Spotted Kiwi males have a call that resembles a warbling whistle, while the female call is harsh raspy, and also warbling.Diet
In the ground, they dig for earthworms and grubs, and they search for beetles, cicada, crickets, flies, wetaWeta
Weta is the name given to about 70 insect species endemic to New Zealand. There are many similar species around the world, though most are in the southern hemisphere. The name comes from the Māori word 'wētā' and is the same in the plural...
, spiders, caterpillars, slugs and snails on the ground. They will also feed on berries and seeds. To find prey, the Great Spotted Kiwi use their scenting skills or feel vibrations caused by the movement of their prey. To do the latter, a kiwi would stick its beak into the ground, then use its beak to dig into the ground. As they are nocturnal, they do not emerge until thirty minutes after sunset to begin the hunt. Kiwis will also swallow small stones, which aid in digestion.
Predation
Because adult Great Spotted Kiwis are large and powerful, they are able to fend off most predators that attack them, such as stoats, ferrets, weasels, pigs, brushtails and cats, all of which are invasive species in New Zealand. However, dogs are able to kill even adults. Stoats, ferrets, possums, cats and dogs will feed on the eggs and chicks, meaning most chicks die within their first five months of life. Once the Great Spotted Kiwi was also preyed upon by the Haast's EagleHaast's Eagle
Haast's Eagle was a species of massive eagles that once lived on the South Island of New Zealand. The species was the largest eagle known to have existed. Its prey consisted mainly of gigantic flightless birds that were unable to defend themselves from the striking force and speed of these eagles,...
, which is now extinct.
Reproduction
Great Spotted Kiwis are monogamous, with pairs sometimes lasting twenty years. NestsBird nest
A bird nest is the spot in which a bird lays and incubates its eggs and raises its young. Although the term popularly refers to a specific structure made by the bird itself—such as the grassy cup nest of the American Robin or Eurasian Blackbird, or the elaborately woven hanging nest of the...
are made in burrow
Burrow
A burrow is a hole or tunnel dug into the ground by an animal to create a space suitable for habitation, temporary refuge, or as a byproduct of locomotion. Burrows provide a form of shelter against predation and exposure to the elements, so the burrowing way of life is quite popular among the...
s. The breeding season begins in June and ends in March, as this is when food is plentiful. Males reach sexual maturity
Sexual maturity
Sexual maturity is the age or stage when an organism can reproduce. It is sometimes considered synonymous with adulthood, though the two are distinct...
at 18 months in captivity, while females are able to lay eggs after three years. In the wild, sexual maturity for both sexes is between ages three and five. Great Spotted Kiwi males chase females around until the females either run off or mate. The pair mates about two to three times during peak activity. The gestation
Gestation
Gestation is the carrying of an embryo or fetus inside a female viviparous animal. Mammals during pregnancy can have one or more gestations at the same time ....
period is about a month. Females do not eat during this period, as the eggs
Bird egg
Bird eggs are laid by females and incubated for a time that varies according to the species; a single young hatches from each egg. Average clutch sizes range from one to about 17...
will take up a fourth of a kiwi's body mass. The egg is so large because the yolk takes up 65% of the egg. In most bird eggs, the yolk takes up about 35 to 40% of the egg. This makes the kiwi egg the largest in proportion to the body. Females must rely on fat stored from the previous five months to survive. Because of the large size of the egg, gestation is uncomfortable to the female, and they do not move much. To relieve the pain, females soak themselves in puddles when they come out of the burrows by dipping their abdomens into the puddle. The egg-laying season is between August and January.
After the female lays the egg, the male incubates the egg while the female guards the nest. Males only leave the nest for a few hours to hunt, and during this time, the female takes over. It takes 75 to 85 days for the egg to hatch. The baby kiwi takes 2 to 3 days simply to get out of its egg. Kiwi babies are precocial
Precocial
In biology, the term precocial refers to species in which the young are relatively mature and mobile from the moment of birth or hatching. The opposite developmental strategy is called "altricial," where the young are born or hatched helpless. Extremely precocial species may be called...
, and are abandoned by their parents after hatching. After ten days, chicks venture out of the burrow to hunt. Most chicks are killed by predators in the first six months of their life. Great Spotted Kiwis reach full size at year six. Unlike most birds, female Great Spotted Kiwis have two ovaries. Most birds have only one. Great Spotted Kiwis are distinguishable from other kiwi species by the fact that they can only produce one egg a year, as it takes so much energy to produce the massive egg.