The KAKAPO - a Flightless Parrot

This fascinating bird, the kakapo, holds several records such as being the world's only flightless parrot as well as being the heaviest parrot in the world, and is also unusual in being nocturnal.

The Kakapo (Māori: kākāpō, meaning night parrot), Strigops habroptila (Gray, 1845), also called owl parrot, is a species of flightless nocturnal parrot endemic to New Zealand. It has finely blotched yellow-green plumage, a distinct facial disc of sensory, vibrissa-like feathers, a large grey beak, short legs, large feet, and wings and a tail of relatively short length. A certain combination of traits makes it unique among its kind—it is the world's only flightless parrot, the heaviest parrot, nocturnal, herbivorous, visibly sexually dimorphic in body size, has a low basal metabolic rate, no male parental care, and is the only parrot to have a polygynous lek breeding system. It is also possibly one of the world's longest-living birds. Its anatomy typifies the tendency of bird evolution on oceanic islands with few predators and abundant food: accretion of thermodynamic efficiency at the expense of flight abilities, reduced wing muscles, a diminished keel on the sternum, and a generally robust physique.

Map of historic Kakapo distribution. Based loosely on an image
(http://en.wikipedia.org/wiki/Image:Kakapohist.png) by James Dignan.
A derivative work of a multi-licensed image
(Image:NZ Locator Blank.svg) by Ozhiker.

Kakapo are critically endangered; as of April 2009, only 125 living individuals are known,most of which have been given names.The common ancestor of the Kakapo and the genus Nestor became isolated from the remaining parrot species when New Zealand broke off from Gondwana, around 82 million years ago. Around 70 million years ago, the kakapo diverged from the genus Nestor. In the absence of mammalian predators, it lost the ability to fly. Because of Polynesian and European colonisation and the introduction of predators such as cats, rats, and stoats, most of the Kakapo were wiped out. Conservation efforts began in the 1890s, but they were not very successful until the implementation of the Kakapo Recovery Plan in the 1980s. As of January 2009, surviving Kakapo are kept on two predator-free islands, Codfish (Whenua Hou) and Anchor islands, where they are closely monitored. Two large Fiordland islands, Resolution and Secretary, have been the subject of large-scale ecological restoration activities to prepare self-sustaining ecosystems with suitable habitat for the Kakapo.

The Kakapo, like many other New Zealand bird species, has historically been important to the Māori, the indigenous people of New Zealand, appearing in many of their traditional legends and folklore. They were also hunted and utilised as a resource both for their meat and for their feathers which were used for making clothing.

Kakapo are large, rotund parrots; males measure up to 60 centimetres (24 in) and weigh between 2 and 4 kilograms (4.5–9 lb) at maturity. Kakapo are unable to fly, having short wings for their size and lacking the pronounced keel bone (sternum) that anchors the flight muscles of other birds. They use their wings for balance, support, and to break their falls when leaping from trees. Unlike other land birds, Kakapo can accumulate large amounts of body fat to store energy making them the heaviest parrot.

The upper parts of the Kakapo have yellowish moss-green feathers barred or mottled with black or dark brownish grey, blending well with native vegetation. Individuals may have strongly varying degrees of mottling and colour tone and intensity — museum specimens have shown that some birds had completely yellow colouring. The breast and flanks are yellowish-green streaked with yellow. Their bellies, undertail, necks and faces are predominantly yellowish, streaked with pale green and weakly mottled with brownish-grey. Because the feathers do not need the strength and stiffness required for flight, they are exceptionally soft, giving rise to the specific epithet habroptilus. Kakapo have a conspicuous facial disc of fine feathers, resembling the face of an owl; thus, early European settlers called it the "owl parrot".

Their beaks are surrounded by delicate vibrissa or "whiskers", which they use to sense the ground for navigation as they walk with their heads lowered. The mandible is mostly ivory-colored, with part of the upper mandible being bluish-grey. The eyes are dark brown. Kakapo feet are large, scaly, and, as in all parrots, zygodactyl (two toes face forward and two backward). They have pronounced claws particularly useful for climbing. The ends of their tail feathers often become worn from being continually dragged on the ground.

Females are easily distinguished from males due to some notable differences: they have a more narrow and less domed head, their beaks are narrower and proportionally longer, their ceres and nostrils smaller, their legs and feet more slender and pinkish grey, and their tails are proportionally longer. While their plumage color is not very different to that of males, the toning is more subtle, with less yellow and mottling. They tend to be more resistant and aggressive than males when handled. Nesting females are also distinguished by a brood patch on the bare skin of the belly.

Like many parrots, Kakapo have a variety of calls. In addition to the booms (click top right hand corner "Arkive" booming sound) and chings of their mating calls, they often skraark to announce their location to other bird.
Kakapo have a well-developed sense of smell, which complements their nocturnal lifestyle.They can discriminate among odours while foraging; a behaviour reported for only one other parrot species.One of the most striking characteristics of Kakapo is their pleasant and powerful odour, which has been described as musty. Given the Kakapo's well-developed sense of smell, this scent may be a social chemosignal. The smell often alerts predators to the largely defenseless Kakapo.

The skeleton of the Kakapo differs from other parrots in several features that are associated with its flightlessness. Firstly, it has the smallest wing size of any parrot. Its wing feathers are shorter, more rounded, less asymmetrical, and have fewer distal barbules to lock the feathers together.

Kakapo are primarily nocturnal; they roost under cover in trees or on the ground during the day and rove their territories at night.
Though the Kakapo cannot fly, they are excellent climbers, ascending to the crowns of the tallest trees. They can also "parachute" - descending by leaping and spreading their wings. In this way they may travel a few meters at an angle of less than 45 degrees.
Having lost the ability to fly, they have developed strong legs. Movement is often by way of a rapid "jog-like" gait by which they can move many kilometres. Females make two return trips each night during nesting from their nest to the food source up to 1 km (0.6 miles) away and males walk from their home ranges to the mating arena up to 5 km (3 miles) away during the mating season (October–January).
Young birds indulge in play fighting and one bird will often lock the neck of another under its chin. Kakapo are a curious species and have been known to interact with humans. Conservation staff and volunteers have engaged extensively with some Kakapo, and they are known to have distinct personalities.

Kakapo Whiskers on face

The kakapo's ancestors adopted camouflaged plumage and became nocturnal. In addition, when Kakapo feel threatened, they freeze, so that they are more effectively camouflaged in the forest vegetation which their plumage resembles. It was not entirely safe at night however as the Laughing Owl was active at this time and it is apparent from their nest deposits on Canterbury limestone cliffs that Kakapo were among their prey.

Mammalian predators, in contrast to birds, rely on their sense of smell and hearing to find prey and often hunt by night. The Kakapo's adaptations to avoid avian predation have thus been quite useless against their new enemies - this is one of the reasons for their massive decline since the introduction of dogs, cats and mustelids following human settlement. A typical way for humans to hunt down Kakapo is by releasing trained dogs.

The beak of the Kakapo is specially adapted for grinding food finely. For this reason, Kakapo have very small gizzards compared to other birds of their size. They are generally herbivorous, eating native plants, seeds, fruits, pollens and even the sapwood of trees. A study in 1984 identified 25 plant species as Kakapo food. They are particularly fond of the fruit of the rimu tree, and will feed on it exclusively during seasons when it is abundant. Kakapo have a distinctive habit of grabbing a leaf or frond with a foot and stripping the nutritious parts of the plant out with their beaks, leaving a ball of indigestible fiber. These little clumps of plant fibers are a distinctive sign of the presence of Kakapo Kakapos are believed to employ bacteria in the foregut to ferment and help digest plant matter.
Kakapo diet changes seasonally. The plants eaten most frequently during the year include some species of Lycopodium ramulosum, Lycopodium fastigium, Schizaea fistulosa, Blechnum minus, Blechnum procerum, Cyathodes juniperina, Dracophyllum longifolium, Olearia colensoi and Thelymitra venosa. Individual plants of the same species are often treated differently. Kakapo leave conspicuous evidence of their feeding activities, from 10×10 m to 50×100 m feeding ground areas. Manuka and yellow silver pine scrubs are obvious signs of their center of feeding activities.

Kakapo Chicks

The Kakapo is the only species of flightless parrot in the world, and the only flightless bird anywhere that has a lek (mating arena) breeding system. Males loosely gather in an arena and compete with each other to attract females. Females watch the males display, or "lek". They choose a mate based on the quality of his display; they are not pursued by the males in any overt way. No pair bond is formed; males and females meet only to mate.

During the courting season, males leave their home ranges for hilltops and ridges where they establish their own mating courts. These leks can be up to 7 kilometres (4 mi) from a Kakapo's usual territory and are an average of 50 metres (160 ft) apart within the lek arena. Males remain in the region of their court throughout the courting season. At the start of the breeding season, males will fight to try to secure the best courts. They confront each other with raised feathers, spread wings, open beaks, raised claws and loud screeching and growling. Fighting may leave birds with injuries or even kill them.

Kakapo Chicks

To attract females, males make loud, low-frequency (below 100 Hz) booming calls from their bowls by inflating a thoracic(Chest) sac They start with low grunts, which increase in volume as the sac inflates. After a sequence of about 20 loud booms, the volume drops off. The male Kakapo then stands up for a short while before again lowering his head, inflating his chest and starting another sequence of booms. The booms can be heard at least one kilometre (0.6 mi) away on a still night; wind can carry the sound at least five kilometres (3 mi). Males boom for an average of eight hours a night; each male may produce thousands of booms in this time. This may continue every night for three or four months during which time the male may lose half his body weight. Each male moves around the bowls in his court so that the booms are sent out in different directions. These booms are also notorious for attracting predators, due to the long range at which they can be heard.

Females are attracted by the booms of the competing males; they too may need to walk several kilometres from their territories to the arena. Once a female enters the court of one of the males, the male performs a display in which he rocks from side to side and makes clicking noises with his beak. He turns his back to the female, spreads his wings in display and walks backwards towards her. The duration of attempted copulation is between 2 to 14 minutes. Once the birds have mated, the female returns to her home territory to lay eggs and raise the chicks. The male continues booming in the hope of attracting another female.

Kakapo Chicks

Female Kakapo lay up to three eggs per breeding cycle. They nest on the ground under the cover of plants or in cavities such as hollow tree trunks. They incubate the eggs faithfully, but are forced to leave them every night in search of food. Predators are known to eat the eggs and the embryos inside can also freeze to death in the mother's absence. Kakapo eggs usually hatch within 30 days, bearing fluffy gray chicks that are quite helpless. After the eggs hatch, the female feeds the chicks for three months, and the chicks continue to remain with the female for some months after fledging. The young chicks are just as vulnerable to predators as the eggs, and young have been killed by many of the same predators that attack adults. Chicks leave the nest at approximately 10 to 12 weeks of age. As they gain greater independence, their mothers may feed the chicks sporadically for up to 6 months.

Because Kakapo are quite long-lived, with an average life expectancy of 95 years and the maximum at about 120 years, they tend to have an adolescence before beginning breeding. Males do not start to boom until about 5 years of age. It was previously thought that female Kakapo's reached sexual maturity at 9 years of age, however in the 2008 breeding season this idea was debunked when two 6 year old females named Apirama and Rakiura laid eggs. Generally females do not seek out males until they are between 9 and 11 years old. Kakapo do not breed every year and have one of the lowest rates of reproduction among birds. Breeding occurs only in years when trees mast (fruit heavily), providing a plentiful food supply. Rimu mast occurs only every three to five years, so in rimu-dominant forests such as those on Codfish Island, Kakapo breeding occurs as infrequently.

Another interesting aspect of the Kakapo's breeding system is that the females can alter the sex ratio of their offspring in relation to maternal condition. Females that eat protein-rich foods produce more male-biased offspring (males have 30–40% more body weight than females). Females produce bias offsprings towards the dispersive sex when competition for resources (such as food) is high and to the non-dispersive sex when food is plentiful; a female Kakapo will likely be able to produce eggs, even when there are few resources, while a male Kakapo will be more capable of perpetuating the species when there are plenty, by mating with several females. This is in support of the Trivers-Willard hypothesis. The relationship between clutch sex ratio and maternal diet has conservation implications, as a captive population maintained on a high quality diet will produce fewer females and therefore fewer individuals valuable to recovery of the species.

The fossil record indicates that in pre-Polynesian times, the Kakapo was New Zealand's third most common bird and it was widespread on all 3 main islands. However, the population of Kakapo in New Zealand has declined massively since human settlement of the country. Since 1891, conservation efforts have been made to prevent extinction. The most successful scheme has been the Kakapo Recovery Plan; this was implemented in 1989 and is still ongoing.

The first factor in the decline of the Kakapo was the arrival of humans. According to Māori folklore, Kakapo were found throughout the country when the Polynesians first arrived in Aotearoa 1,000 years ago;subfossil and midden deposits show that they were present throughout the North Island, South Island and Stewart island before and during early Māori times. Māori settlers from Polynesia hunted the Kakapo for food and for their skins and feathers, which were made into luxurious capes.They used the dried heads as ear ornaments. Due to its flightlessness, strong scent and habit of freezing when threatened, the Kakapo were easy prey for the Māori and their dogs. Their eggs and chicks were also predated by the Polynesian Rat or kiore, which the Māori brought to New Zealand. Furthermore, the deliberate clearing of vegetation by Māori reduced the habitable range for Kakapo. Although the Kakapo were extinct in many parts of the islands by the time Europeans arrived, including the Tararua and Aorangi Ranges, they were still present in the central part of North island and forested parts of South island.

From the 1840s, European settlers cleared vast tracts of land for farming and grazing, further jeopardising the Kakapo and their habitat. They brought more dogs and other mammalian predators, including domestic cats, black rats and stoats. Europeans knew little of the Kakapo until George Gray of the British Museum described it from a skin in 1845. As the Māori had done, early European explorers and their dogs fed on Kakapo. In the late 1800s, Kakapo became well-known as a scientific curiosity, and thousands were captured or killed for zoos, museums and collectors. Most captured specimens died within months. From at least the 1870s, collectors knew the Kakapo population was declining; their prime concern was to collect as many as possible before they became extinct.

Kakapo Stamps

In the 1880s, large numbers of mustelids (stoats, ferrets and weasels) were released in New Zealand to reduce rabbit numbers, but they also preyed heavily on many native species including the Kakapo. Other browsing animals, such as introduced deer, competed with Kakapo for food, and caused the extinction of some of its preferred plant species. Kakapo were reportedly still present near the head of the Whanganui River as late as 1894, with one of the last records of a Kakapo in the North Island being a single bird caught in the Kaimanawa Ranges by one Te Kepa Puawheawhe in 1895.

The Kakapo has a rich tradition of Māori folklore and beliefs associated with it as a species. Their irregular breeding cycle was noted to be associated with heavy fruiting or "masting" (mast year is a year in which vegetation produces a significant abundance of  fruit) events of particular plant species such as the Rimu which led the Māori to credit the bird with the ability to foretell the future. Used to substantiate this claim were reported observations of these birds dropping the berries of the Hinau and Tawa trees (when they were in season) into secluded pools of water to preserve them as a food supply for the summer ahead; the Māori practice of immersing food in water for the same purpose is believed to originate from these observations

The meat of Kakapo made good eating and was considered by Māori to be a delicacy[and they were hunted for food during the time they were still widespread. One source states that its flesh "resembles lamb in taste and texture", although European settlers have described the bird as having a "strong and slightly stringent flavour".

In breeding years, the loud booming calls of the males at their mating arenas made it easy for Māori hunting parties to track them down, and they were also hunted while feeding or when having dust baths in dry weather. The birds were caught, generally at night, using snares, pitfall traps, or by groups of domesticated Polynesian dogs which accompanied the hunting parties — sometimes they would use fire sticks of various sorts to dazzle the birds in the darkness, stopping them in their tracks and making the capture easier.Cooking was either done in a hāngi or in gourds of boiling oil. The flesh of the birds could be preserved in their own fat and stored in containers for later consumption — hunters of the Ngāi Tahu tribe would pack the flesh in baskets made from the inner bark of Totara tree or in containers constructed from kelp. Bundles of Kakapo tail feathers were attached to the sides of these containers to provide decoration and a way to identify their contents. Also taken by the Māori were the bird's eggs, which are described as "white-ish  but not pure white", and about the same size as a kererū (New Zealand Pigeon )egg.

As well as eating the meat of the Kakapo they killed, Māori would use Kakapo skins — with the feathers still attached — to create cloaks and capes. Each one required up to 11,000 feathers to make. Not only were these garments very beautiful, they also kept the wearer very warm. They were highly valued, and the few still in existence today are considered taonga (treasures) — indeed, the old Māori adage "You have a Kākāpō cape and you still complain of the cold" is used to describe someone who is never satisfied. Kakapo feathers were also used to decorate the heads of taiaha, but were removed before actual use in combat.

Despite all, the Kakapo was also regarded as an affectionate pet by the Māori. This was corroborated by European settlers in New Zealand in the 19th century, among them George Edward Grey, who once wrote in a letter to an associate that his pet Kakapo's behavior towards him and his friends was "more like that of a dog than a bird.

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Source(s): wikipedia | arkive.org | terranature | doc.govt.nz | kakaporecovery.org