Kea (Nestor notabilis)

The kea is a large, crow-sized parrot about 48 centimeters, or 19 inches, long as an adult and weighs between 800 grams (1.8 pounds) and 1 kilogram (2.2 pounds).

Kea display sexual dimorphism as the male is about 5% longer than the female, and the male’s upper beak is 12–14% longer than the female’s. Kea have decurved upper bills or culmens, but females have shorter, less curved culmens and weigh about 20 percent less than males.

The kea has mostly dull bronze, olive-green plumage. Its underparts are brownish-green with dark-edged feathers.

The feathers on the sides of the kea’s face are dark olive-brown with dark-edged feathers. It has a grey-brown beak having a long, narrow, curved upper beak. The adult has dark-brown irises, and the cere, eyerings, legs, and feet are grey-brown.

The underwing coverts are scarlet red-orange with yellow barring and notching that extends to the undersides of the flight feathers. The feathers on its lower back and rump are dull red-orange reaching to the upper-tail coverts, and some of the outer webs of their primary feathers are dull-blue.

The kea has a short, broad, bluish-green tail with a black tip. The upper surface of the tail is bronze-green. Feather shafts project at the tip of the tail and the undersides of the inner tail feathers have dull, yellow-orange transverse stripes.

Juvenile kea generally resemble adults, but have yellow eyerings, crowns, and cere, an orange-yellow lower beak, and grey-yellow legs.

Kea can live 14.4 years in captivity. Lifespan in the wild has not been thoroughly studied, but the oldest recorded wild bird was at least 22 years of age.

SEXUAL DIMORPHISM

Larger Males

BODY LENGTH

48 cm. / 19 in.

BODY MASS

800-1,000 g. / 2 lb.

LIFESPAN

14-22 yr.

GENERATION LENGTH

12 yr.

LOCOMOTION

Digitigrade

The kea was described by ornithologist John Gould in 1856.

The genus Nestor contains four species: the New Zealand kaka (Nestor meridionalis), the kea (Nestor notabilis), the extinct Norfolk kaka (Nestor productus), and the extinct Chatham kaka (Nestor chathamensis). All four are thought to stem from a proto-kākā, dwelling in the forests of New Zealand five million years ago. Together, they form the parrot superfamily Strigopoidea, an ancient group that split off from all other Psittacidae before their radiation.

The kea’s closest relative is the flightless kakapo (Strigops habroptilus), though their only competitor is the closely related kaka. The kaka is a lowland species, and is smaller and darker than the kea with crimson underparts.

The kea is one of ten endemic parrot species in New Zealand.

KINGDOM

Animalia

PHYLUM

Chordata

CLASS

Aves

ORDER

Psittaciformes

FAMILY

Strigopidae

GENUS

Nestor

SPECIES

notabilis

SUBSPECIES

None

The kea’s scientific name is Nestor notabilis.

The kea’s specific epithet, the Latin term notabilis, means noteworthy.

The common name kea is from Māori, an onomatopoeic representation of their loud, in-flight call, keee-aa. The word kea is both singular and plural.

The kea has been called The Clown of New Zealand’s Southern Alps by the New Zealand Department of Conservation.

ALTERNATE

The Clown of New Zealand’s Southern Alps

GROUP

Flock, Pandemonium

MALE

Cock

FEMALE

Hen

YOUNG

Fledgling, Hatchling

The kea is one of ten endemic parrot species in New Zealand and is native to the mountains of South Island, New Zealand.

The population is sparsely distributed across a range of approximately 3.5 million hectares from Kahurangi to Fiordland, and including the Kaikoura Ranges.

The population is a fraction of what it once was, largely due to persecution between the late 1860s and early 1970s, although pockets of high population densities persist in some areas, such as around Arthur’s Pass and South Westland.

The feasibility of a captive or island insurance population needs to be investigated.

EXTANT

New Zealand

Kea are alpine parrots and inhabit temperate and subtropical/tropical moist lowland forests, shrubland, grassland, and even artificial terrestrial habitats, such as pastureland and urban areas.

The kea mostly inhabits high-altitude forest and alpine basins, although birds will often frequent and nest in coastal lowland flats. Kea live in wooded valleys and southern beech (Nothofagus) forests that line sub-alpine scrublands at 600 to 2,000 meters.

Its foraging habitat includes all types of native forest, sub-alpine scrub, tussock. and herb-field.

In summer, kea inhabit high elevation scrub and alpine tundra areas. In autumn, they move to higher elevations to forage for berries. In winter, kea move below the timberline.

FOREST

Temperate, Subtropical/Tropical Moist Lowland

SHRUBLAND

Subtropical/Tropical High Altitude

GRASSLAND

Temperate, Subtropical/Tropical High Altitude

ARTIFICIAL/TERRESTRIAL

Pastureland, Urban Areas

Kea are diurnal, rising in the early morning to begin calling and then foraging until late morning. They generally roost during the middle of the day and begin foraging again in the evening, sometimes until after dark, when they go to roost for the night on tree branches. The timing of these daily activities varies with the weather; kea are fairly heat-intolerant and spend more time roosting on hot days.

Kea are highly intelligent, social birds. They live in family groups and aggregations of 30 to 40 birds and often forage at prime feeding grounds, such as garbage dumps, ski fields, and cabins. Kea exhibit a variety of social behaviors, including intricate play.

Kea have dominance hierarchies, but these hierarchies are not necessarily linear. For example, an adult male may be dominant to a subadult male, who is dominant to a juvenile male, who, in turn, is dominant to the adult male. Experiments on cooperation in kea suggest that dominant individuals can force subordinates to cooperate in tasks that benefit only the dominant birds.

It has been shown that kea in captivity can learn complicated tasks from observing others, though this ability has not been shown for kea in the wild.

Kea perceive visual, tactile, auditory, and chemical stimuli. Kea communicate with a wide repertoire of vocalizations, including the loud, keee-aa flight call for which they are named. They also communicate by fluffing their head feathers into various facial expressions and by posturing.

CIRCADIAN RHYTHM

Diurnal

MOVEMENT PATTERN

Non-Migrant

Kea are opportunistic, omnivorous parrots. The leaves, buds, and nuts of southern beeches (Nothofagus) are especially important in the kea diet.

Kea feed on plant matter, such as leaves, buds, nuts, roots, stems, fruit, seeds, flowers, nectar, pollen, and berries. They mostly feed on berries and shoots. They also feed on insects, like beetle grubs and grasshoppers, and have been reported to eat land snails, rabbits, and mice. Kea have also been recorded eating other bird and mammal species including Hutton’s shearwater chick and eggs (Puffinus huttoni), racing pigeon, stoat (Mustela erminea) and possum carcasses. They have also been known to consume fat from the carcasses of hunted introduced mammal species such as tahr, deer, and chamois. Kea have gained a reputation for attacking sheep (Ovis aries), although they usually only prey on wounded or diseased sheep and feed on the meat and bone marrow.

The foods kea consume vary by season. In spring, they eat mountain daisies (Celmisia) and dig in the soil for small plants and insects. In summer, kea consume the nectar and pollen of flowering mountain flax (Phorium colensoi) and rata (Metrosideros). They eat berries of coprosma (Coprosma) and snow totara (Podocarpus nivalis), and eat the leaves, fruit, seeds, and flowers of other plants. In summer, they also eat beetle grubs, grasshoppers, and land snails. In fall, kea feed on mountain beech leaves and buds and continue foraging on the roots, bulbs, fruit, seeds, and stems of other plants. Kea scavenge on trash heaps year round and relish the flesh and bone marrow from carcasses, but these food sources become particularly important in winter, when plant foods are scarce. They are also known to attack the fatty area around the kidneys of live sheep left high in the alpine areas above 600 meters during winter when resources are low.

PREFERENCE

Generalist

STYLE

Forager

Kea have been observed breeding at all times of the year, except late autumn. Their main reproductive period lasts from July to January. Kea have a polygynous mating system. Males fight for dominance, and the hierarchy is strict. As few as 10% of males may be allowed to breed in certain years.

Kea copulation is often initiated by the female, who approaches the male and invites play or adopts a submissive posture and solicits preening. The male then feeds the female a regurgitated meal and mounts her.

Kea nest in holes, under logs, in rocky crevasses, burrows under rocks, and among tree roots, mainly within forest. They have clutches of two to four eggs, and incubate the eggs for three to four weeks.

Kea have both maternal and paternal parental investment as both parents care for the young. Once a female kea lays her eggs, she sits on the nest and incubates them for three weeks. During this time, she rarely leaves the nest and the male feeds her. After the eggs hatch, the male continues to feed the female, and she, in turn, feeds the chicks. After a month, the male begins feeding the chicks himself.

Juvenile kea have yellowish crowns and ceres. Kea hatchlings are altricial and fledge after at 9 to 13 weeks of age. At this point, the male assumes sole responsibility for feeding them. He continues feeding his fledglings for up to five to six weeks. Afterward, the juveniles disperse from their natal area and travel together in flocks for two to three years before settling down.

Male kea are sexually mature after four or five years, while females become sexually mature as early as three years of age.

BREEDING SEASON

January-July

BREEDING INTERVAL

1 Year

BROOD

2-4 Eggs

PARENTAL INVESTMENT

Maternal, Paternal

INCUBATION

3-4 Weeks

FLEDGLING

13 Weeks

INDEPENDENCE

18-19 Weeks

SEXUAL MATURITY

3-5 Years

Kea, being opportunistic, generalist omnivorous foragers, are primary, secondary, and higher-level consumers.

In the past, kea probably had an array of competitors, such as New Zealand kaka (Nestor meridionalis), moa (Anomalopteryx, Dinornis, Emeus, Euryapteryx, Megalapteryx, and Pachyornis spp.), kakapo (Strigops habroptila), North Island takahe (Porphyrio mantelli), and Chatham ravens (Corvus moriorum), but human settlement fueled a mass extinction of New Zealand’s native birds. Moa, takahe, and Chatham ravens are now extinct, and kakapo are extremely rare. Only kaka remain to compete with kea and, where their ranges overlap, these two closely related species use many of the same food resources. The kaka is a lowland species, and is smaller and darker than the kea with crimson underparts.

New Zealand falcons (Falco novaeseelandiae) have been observed attacking kea, but no one has reported an incident of successful predation. Kea remain alert for air attacks when foraging and they band together to chase falcons that threaten a member of their group.

It has been proposed that life in an extreme alpine environment has encouraged kea to opportunistically and inquisitively explore their surroundings. Increasingly, the parrots have come into contact with human habitations, sometimes foraging at refuse dumps, ski fields, and cabins. Kea commonly investigate human belongings, and are known to destroy car accessories, such as windshield wipers and weather stripping, and ski lodge equipment. These birds have also shredded hiking boots and have stolen objects, such as sunglasses. The damage can cause serious problems, such as when the birds rip out car wiring and destroy ski-lift warning systems. Birds are also sometimes killed through accidents with human objects, such as motor vehicles, snow groomers, rubbish bins, and electricity sub-stations.

Kea have gained a reputation for attacking sheep (Ovis aries), although they usually only prey on wounded or diseased sheep. Once kea attack sheep, the wounds can become infected with Clostridium bacteria. The bacteria can cause blood poisoning, which can be fatal to sheep. Up until its partial protection in the early 1970s, over 150,000 kea were shot in a bounty scheme, established because rogue individuals were found to be attacking sheep as a source of fat. Deforestation for pasture has placed pressure on the species, and farmers still kill an unknown number of birds each year.

Parrot-smuggling is also a lucrative business, and kea are often captured and exported for the black market pet trade.

Kea are important for New Zealand’s tourism industry. These birds have been called The Clown of New Zealand’s Southern Alps by the New Zealand Department of Conservation, attracting crowds when they convene on automobiles.

Pets/Display Animals, Horticulture

International

It is unknown exactly how many kea are left in the wild. Estimates range from only 2,000 to 5,000 birds. The current population has been estimated by the IUCN to number 6,000 individuals. A conservative estimate of one adult female per 2,000 hectares of forest gives a total population of 4,000 mature individuals in the population. Productivity estimates predict one juvenile for every breeding pair, giving a total population of about 6,000 birds.

Although kea populations appeared stable in 2001, especially in national parks and other protected areas, their population trend is currently decreasing and continuing to decline rapidly. The population is a fraction of what it once was, largely due to persecution between the late 1860s and early 1970s, although pockets of high population densities persist in some areas, such as around Arthur’s Pass and South Westland. Recent survey data indicate that kea have undergone substantial recent population declines. For example, density in the upland beech forest of Nelson Lakes National Park in 2011 was approximately one adult female kea per 2,750 hectares, down from about one per 550 hectares in 1998. This represents an 80% decline in density over 13 years or just over one generation. There are also numerous anecdotal reports of decreases from other unmanaged areas. Although densities in other populations are much higher than at Nelson Lakes, it is likely that kea in areas not subject to predator control are continuing to decline. The total population decline over the last three generations, or 36 years, is likely to have been more than 50% but less than 80%.

Further research is being conducted on the kea’s ecology, genetics, and population dynamics. The population needs to be censused at frequent intervals. The feasibility of a captive or island insurance population needs to be investigated.

MATURE INDIVIDUALS

4,000

FRAGMENTATION

Not Fragmented

Introduced mammalian predators, such as stoats (Mustela erminea), domestic cats (Felis catus), and brushtailed possums (Trichosurus vulpecula) have spread into most of the kea’s range. Episodic, high mortality events are thought to be associated with plagues of stoats which occur after mast seeding of native beech and rimu. Monitoring by the New Zealand Department of Conservation between 2009-2014 found that only 2% of kea nests in areas without pest control were successful, in contrast with a 27% success rate in areas treated with aerial 1080 in 2015. It is estimated that around 60% of kea nests are normally attacked by predators, especially stoats, which may also kill adults; this can rise to as many as 99% of nests being attacked in a stoat plague.

For the kea to thrive, the control of introduced mammals needs to continue. However, ingestion of lead from building components and the 1080 toxin used in invasive control have potentially widespread impacts on the population. The sources of lead posing a risk to the kea need to be identified, then either removed or replaced with lead-free alternatives or cover to prevent kea access. Kea need to be excluded from predator-control toxins and devices, and the use of risky devices needs to be limited. Efforts to use a bird repellent to deter kea from 1080 toxin have not so far proved effective.

Climate change may also pose a threat through possible future influences on its high altitude habitat.

AGRICULTURE & AQUACULTURE

Livestock Farming & Ranching

TRANSPORTATION & AQUACULTURE

Roads & Railroads

BIOLOGICAL RESOURCE

Hunting & Trapping Terrestrial Animals

HUMAN INTRUSIONS & DISTURBANCE

Recreational Activities

INVASIVE & OTHER PROBLEMATIC SPECIES, GENES, & DISEASES

Invasive Non-Native/Alien Species/Diseases

CLIMATE CHANGE & SEVERE WEATHER

Habitat Shifting & Alteration

OTHER OPTIONS

Other Threats

The kea has been fully protected by national law since 1986. Kea are protected within New Zealand by the Wildlife Act of 1953, the National Parks Act, the Animals Protection Act, and the Trade in Endangered Species Act. These laws prohibit the capture of kea on private and public lands, prohibit their mistreatment, and ban their export.

A project to involve communities in kea conservation is underway. Advocacy is aimed at informing alpine users of ways to minimize adverse impacts and to change the negative image of the species often held by high-country farmers and ski-field operators. The Kea Conservation Trust operates a conflict resolution program. Predator control has been carried out and there are plans for it to continue as part of New Zealand’s “Battle for our Birds”. For the kea to thrive, advocacy campaigns need to be continued.