kākāpō – a strange Night Parrot

New Zealand’s islands are home to a plethora of weird and wonderful animals, but perhaps none are as weird and wonderful as the kākāpō. The giant flightless parrot exists on only a handful of offshore islands in New Zealand where it is safe from the new predators which are currently roaming New Zealand’s mainland. There numbers are so low that each and every existing individual has been given a name.

The kākāpō is a large, nocturnal, lek-breeding, flightless parrot, a rare oddity. It is also critically endangered and is the focus of considerable attention to conservation. Once it was common throughout the forests of New Zealand before humans arrived, but it was brought to the brink of extinction(as low as 50 birds in mid 1990s), by predation of introduced mammals from outside world. But a steady increase in numbers has resulted by the transfer of the entire population to predator-free islands and intensive intervention at every stage of their lives. kākāpō is truly unique and have no close relatives.

Taxonomy and Naming

The common English name “kakapo” comes from the Māori “kākāpō”, kākā (“parrot”) + pō (“night”) meaning Night Parrot. The name is both singular and plural.

Scientific Name:Strigops habroptilus Introduced by G.R. Gray, in 1845.
Order: Psittaciformes.
Family: Strigopidae.
New Zealand status: Endemic.
Conservation status: Nationally Critical.
Other names: kākāpo, owl-parrot, tarapo, tarepo, night parrot.
Geographical variation: Nil (Only found in New Zealand’s Islands).
Found in: Codfish Island/Whenua Hou, Anchor Island and Te Hauturu-o-Toi/Little Barrier Island.
Threats: Human induced Predators, disease, genetic inbreeding, infertility.
Population: A total of 213 birds is alive as of Nov 2019. All carry radio transmitters and are intensively monitored and managed.
LifeSpan: Approx 90 Yrs plus.

Description

kākāpō has finely blotched yellow-green plumage, a distinct facial disc, a large gray beak, short legs, large feet, and relatively short wings and tail. It is not just the only flightless parrot in the world, but also the herbivorous, visibly sexually dimorphic in body size, has a low basal metabolic rate with no male parental care, and is the only parrot with a polygynous lek breeding system. It may also be one of the longest-living birds in the world.

Although a member of the family Psittacidae, kākāpō are unique in many ways. kākāpō are solitary, nocturnal and flightless. They are quiet, slow moving and usually asleep in a tree during the day. Their mossy colors make ideal camouflage. It is believed they evolved with no ground predators and only a few extinct birds of prey. Their coloration and tendency to remain motionless during the day supports this theory. When the sun goes down kākāpō demonstrate how well adapted they are for darkness. They can charge through bush with precision. They are keenly sensitive to sound and in many ways transform into an agile creature when night falls. It is clear night-time is when a kākāpō is at its best.

kākāpō is also the heaviest parrot. Typically, females weigh between 1100 grams and 2000 grams anywhere. Males can weigh up to 1600 grams and in the breeding season they can weigh up to 4000 grams. The wings are not used to fly, and when climbing down to forage, the large bird still falls to the ground without grace. Although their wing feathers are distributed similarly to other parrots, they are shorter, comparatively rounded, show less asymmetry of vanes, and have fewer interlocking barbules at their tips.

Kaka and kea are the only species with which kākāpō may be confused, but they can be easily distinguished by their moss green colour, large size, flightlessness and nocturnal habit. It is also very unlikely that any kākāpō exists other than at a few managed sites, so there is very little chance of misidentification.

Kākāpō are solo hikers with big voices and a tendency to freeze when threatened.

Personality & Behaviours

Every kākāpō has a personality of its own. They are ranged from friendly to grumpy or completely aloof. Some are playful and cheeky, some are explorers, and some are insatiable lovers of food. Kākāpō are lonely creatures, although new evidence shows that they are not as lonely as they once thought. In small groups of two to four, females and young birds are occasionally found together, playing or hanging out in the same tree, or gathering near a food hopper. Neighbors with occasionally loud’ skrarks’ use to keep in touch with each other.

Adult males and females meet only to breed, and the females raise their chicks alone. During the day, kākāpō sleep in ground or tree-top roosts. At night, they forage for food. kākāpō do everything slowly, including walking. Kākāpō evolved without the presence and effect of mammals. They gained weight and lost their flying ability. Now, their wings are used for balance and more graceful falls, but lighter females can manage short glides across gaps of 3–4 m.
They kept their head for heights though, using their strong claws to climb 20 m high rimu trees. They’re also excellent hikers, with large strong legs. They can walk several kilometres at a time, and turn on a fair burst of speed too.

Kākāpō freeze when they’re disturbed, relying on their mottled feathers to camouflage them. It’s an excellent defence against predators that rely on sight, such as the now-extinct Haast’s eagle and large Eyles harrier. Their nocturnal habits are also an adaptation to avoid flying daytime predators. But introduced mammalian predators such as cats and stoats use smell to hunt, and are active day and night. That’s what makes them such a threat to the distinctive-smelling flightless kākāpō.

Kākāpō have longer lifespan and don’t start breeding until they’re about five years old. They only breed when there is abundance of fruits on rimu trees called as rimu mast years which occurs in every two to four years.
Male kākāpō put on displays at fixed locations to attract female attention, and they don’t help to raise any offspring. It’s called lek breeding. No other New Zealand bird does it, and no other parrot species in the world is known to lek breed.
In breeding years, adult male kākāpō takes their display to the stage in about December. Each male finds a prominent ridge, rock or hilltop with low-growing vegetation for the better place to call from. Then he forms a track-and-bowl system. A network of tracks radiating from a shallow bowl-like depression in the earth.
The primary bowl usually has a clear area of ground around it and the neatly trimmed tracks connecting two or three additional bowls, but sometimes up to ten.
Settled in his bowl, the male inflates his thoracic air sac. Then he emits a deep, low-frequency ‘boom’ in every 1–2 seconds. Their booms can be heard 300–400 meter away on flat ground, or up to 5 km away in the mountains. After 20–30 booms he makes a high-pitched metallic ‘ching’. It helps any interested females to pinpoint his position. His serenade can last for eight hours without any break, every night for two or three months.

Males make a deep booming call known as (“booming”) and a loud wheezing call known as (“chinging”) to attract mates to their leks. Both sexes make a loud high pitched skraak call which is known as (“skraaking”).

Researchers are still not sure which qualities makes a male kākāpō more attractive. Some are clearly favorites and will attract many females, while others are not selected at all.
Females can travel long distances to mate with their preferred male or males, often walking past other males in the process.

During breeding season male kākāpō are intensely motivated to copulate. Male kākāpō will charge and mount female kākāpō , other species of birds and inanimate objects that appear in close proximity to the bowl. Once contact is made, the male will copulate for up to 90 minutes.

Nesting : Nest are made in good shelters. Hollow trees, or caves made by rocks and roots are among best place for nesting. Female kākāpō lays minimum one to maximum four eggs, slightly smaller than chicken eggs. The eggs hatches after about 30 days.
As a solo parent, the female must leave her nest unattended at night to find food. Normally Chicks fledge after about 10 weeks but the mother may keep feeding her chicks for up to six months.

Kākāpō are herbivorous and they only eat plants mostly fibrous plants. Their diet is diverse, including fruit from the tips of high rimu branches, juicy supplejack vines and orchid tubers grubbed out of the ground. Rimu fruits are their most loved food and When key food species are abundant, kākāpō will feed almost exclusively on them. And when there’s plentiful rimu fruit, a breeding season begins. Kākāpō often browse tough foliage by passing it through their bill from bottom to top, using their feet to pull it through. They chew and compress the foliage against the roof of their finely ridged upper mandible and suck out the nutrients. All that’s left is a fibrous ball hanging off the plant.
Since all kākāpō are being monitored they are also given supplementary foods to boost the kākāpō diet with specially-formulated pellets.
The supplementary food keeps the birds in good reproductive condition plus increases egg production in breeding seasons and help mothers feed their chicks when there’s a shortfall of rimu fruit.

Threats and conservation

Polynesian settlement: When the first Polynesian settlers Māori people arrived in New Zealand about 700 years ago, they found that kākāpō was an easy prey. They ate them as their food and made fluffy cloaks with their feathers. They used the dried heads as ear ornaments. The Polynesian dog and the rat came along with the Polynesians, who also preyed on kākāpō. By the time European settlers arrived in the early 1800s, kākāpō were confined to the central northern island and forested areas of the southern island.

European settlement: The kākāpō’s demise was accelerated through European settlement. A great deal of habitat was lost through forest clearance, and introduced possums and deers which depleted the remaining forests of their food. Devastating predators like cats, stoats and two more species of rat were also introduced during this period and Kākāpō were in serious trouble.

Adult kākāpō are vulnerable to predation by cats and stoats, while their eggs and chicks can be easily killed by rats. Since Females alone incubate eggs and raise chicks, they have to spend long periods away from the nest feeding. Due to this behaviour eggs and chicks becomes more vulnerable to predation. Due to longer chicks rearing , nests become smelly and it becomes easy for predators to find their chicks. kākāpō usually freeze and rely on enigmatic colouration to hide them from predators. Usually this strategy worked when the main predators were birds that hunted by sight but it became completely ineffective strategy for the mammalian predators that hunted by smell.

Early Conservation: The government of New Zealand started its first effort to save kākāpō in 1894. Richard Henry, a pioneer conservationist, led an attempt to move several hundred birds to the Fiordland predator-free Resolution Island. But the island did not remain free from predators and stoats arrived within six years, eventually destroying the population of kākāpō. The kākāpō were nearly extinct species by the mid-1900s. But few people noticed them, but no one took care of them actively. Only a few birds clung to life in New Zealand’s most isolated areas.

From 1949 to 1973, more than 60 expeditions were conducted by the newly formed New Zealand Wildlife Service, focusing mainly on Fiordland. Six kākāpō were captured, but they were all males, and within a few months of captivity, five out of six died. A new initiative was introduced in 1974, despite the fact that no birds remained. There were 18 more kākāpō found in Fiordland by 1977. However still there were no females. In 1977, in southern Rakiura (a large island free of stoats, ferrets and weasels) a large population of males was heard booming. There were about 200 males, and females were also present which later got confirmed in 1980.

Attempts to protect kākāpō from introduced predators by transferring them to Resolution Island in the 1890s failed when stoats swam to the island. By the 1980s and 1990s transfers to completely predator-free Maud Island and to Hauturu and Whenua Hou Island which only had kiore(polynation rat), halted the kākāpō’s decline. However, the population did not start to increase and By 1995, although at least 12 chicks had been produced on the islands, only three had survived. The kākāpō population had slumped to 51 birds. Once kiore were removed from the islands and the birds were more intensively managed their population increased. Intensive management comprised moving the birds between islands, protecting nests from rats, supplementary feeding adults, closely monitoring eggs and chicks, and rescuing and hand-raising any failing chicks.

kākāpō has very poor genetic diversity and low fertility as a result. Many recent management of conservation has focused on managing matings and using artificial insemination to minimize further genetic loss. Currently, kākāpō is held on three islands (Whenua Hou, Anchor Island and Hauturu) in 2016, 32 chicks survived on all three islands.

The kākāpō population is a record high of 213 birds for the first time in over 70 years. Today there is probably more kākāpō alive than in the last 70 years at any time.

After a rimu mast year, the 2018/19 breeding season was the largest ever recorded following by unprecedented quantities of rimu fruit that kākāpō needs to successfully breed and hatch chicks on the main breeding islands.

The total population of kākāpō is currently 142 adults and 71 living chicks. All of these live on remote islands away from predators.

However, in late April, the first case of aspergillosis in the kākāpō population was detected. Since then 36 birds, or a fifth of their total numbers, have been sent to veterinary hospitals around the country for diagnosis and treatment.

Summary of Unique natural history and Behavior of the kākāpō.

• Nocturnal
• Flightless
• Solitary
• Long lived
• Heaviest Parrot
• Emit/detect odor
• Lekking species
• Males build tracks and bowls
• Males defend bowls
• Males boom and ching for mates
• Males have strong drive to copulate
• Copulate for long periods of time
• Females incubate and raise offspring alone
• High fiber low protein diet
• Specific food and amount required for raising offspring
• Skraak vocalization used under various circumstances
• Every known living ,kākāpō has been given a name

Sources :

• http://www.kakaporecovery.org.nz/
• http://en.wikipedia.org/wiki/Kakapo
• http://www.birdlife.org/datazone/speciesfactsheet.php?id=1492
• http://nzbirds.com/birds/kakapo.html
• KAKAPO interactive Dashboard
• Department of Conservation