Porphyrio hochstetteri

Geographic Range

South Island takahe are endemic to New Zealand's South Island. Following conservation and reintroduction efforts South Island takahe have been introduced to the islands of Tiritiri Matangi, Kapiti, Mana, Maud, and Rarotoka, off the coast of New Zealand's South Island.

• Biogeographic Regions
• australian australian
  • native native

• Other Geographic Terms
• island endemic island endemic

Habitat

Mainland populations can be found in alpine tussocks grasslands and sub-alpine shrublands. Island populations live in modified grasslands.

• Habitat Regions
• temperate temperate
• terrestrial terrestrial

• Terrestrial Biomes
• savanna or grassland savanna or grassland
• scrub forest scrub forest

Physical Description

South Island takahe are large, flightless rails . South Island takahe are very colorful, with deep to peacock-blue heads, breasts, necks, and shoulders. The wings and back are olive-green and blue. The bill is large and red, as is the shield. South Island takahe also have large, powerful, red legs and feet. Young South Island takahe are deep blue to black at hatching but quickly take on the coloration of adults. There is little sexual dimorphism, although males average slightly larger in mass.

• Other Physical Features
• endothermic endothermic
• homoiothermic
• bilateral symmetry bilateral symmetry

• Sexual Dimorphism
• sexes alike
• male larger

Reproduction

Mate selection involves several courtship behaviors. Duetting and neck-pecking, of both sexes, are the most common behaviors. Following courtship, the female solicits the male by positioning her back toward the male, spreading her wings, and putting her head down. Allopreening and copulation is then done by the male.

• Mating System
• monogamous monogamous

Breeding occurs following the New Zealand winter, ending sometime in October. A deep, bowl-shaped nest is constructed of fine grass. Females lay a clutch of 1 to 3 eggs that hatch after about 30 days of incubation. Different survival rates have been reported, but on average only one chick will survive to adulthood.

• Key Reproductive Features
• iteroparous iteroparous
• seasonal breeding seasonal breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual sexual
• oviparous oviparous

South Island takahe pairs, when not incubating eggs, are generally seen in close proximity to each other. In contrast a breeding pair is rarely together during incubation, so it is assumed that one bird is always on the nest. Females incubate significantly more during the day and males more at night. Post-hatch observations suggest that both sexes spend similar amounts of time feeding the young. The young are fed until they are about 3 months old, at which time they become independent.

• Parental Investment
• pre-fertilization
  • provisioning
  • protecting
    • female
• pre-hatching/birth
  • provisioning
    • female
  • protecting
    • male
    • female
• pre-weaning/fledging
  • provisioning
    • male
    • female
  • protecting
    • male
    • female
• pre-independence
  • provisioning
    • male
    • female
  • protecting
    • male
    • female

Lifespan/Longevity

Very little is known about South Island takahe lifespan in the wild. Sources estimate they can live between 14 and 20 years in the wild. In captivity South Island takahe have lived up to 20 years.

Behavior

South Island takahe are highly territorial, most confrontations occur during incubation. They are active during the day.

• Key Behaviors
• terricolous
• diurnal diurnal
• motile motile
• sedentary sedentary
• territorial territorial

Home Range

Home ranges of South Island takahe vary in size from 1.2 to 4.9 ha., densities are highest in moist lowland habitats.

Communication and Perception

There is little available information on communication of Porphyrio hochstetteri at this time. Visual and tactile cues are used in mating.

• Communication Channels
• visual visual
• tactile tactile

• Perception Channels
• visual visual
• tactile tactile
• acoustic acoustic
• chemical chemical

Food Habits

South Island takahe primarily consume the leaf bases and seeds of native tussock grasses, including broad leafed snow tussock ( Chionochloa rigida ), mid-ribbed snow tussock ( Chionochloa pallens ) and curled snow tussock ( Chionochloa crassiuscula ). They occasionally take insects as well, especially when raising young. They also eat rhizomes of native ferns.

• Primary Diet
• herbivore herbivore
  • folivore folivore

• Animal Foods
• insects

• Plant Foods
• leaves
• roots and tubers
• seeds, grains, and nuts

Predation

South Island takahe do not have any native predators. Populations have declined as a result of anthropogenic changes such as habitat destruction and modification, hunting, and the introduction of mammalian predators and competitors, including dogs, red deer, and stoats.

Ecosystem Roles

South Island takahe numbers are exceptionally low, so their ecosystem impacts are very small. They do impact vegetation communities through their grazing.

Economic Importance for Humans: Positive

South Island takahe represent unique adaptation towards flightlessness in island birds, especially rails . Because of their uniqueness and rarity, they support ecotourism of people interested in viewing them in introduced populations on offshore islands.

• Positive Impacts
• ecotourism ecotourism
• research and education

Economic Importance for Humans: Negative

There are no known adverse effects of Porphyrio hochstetteri on humans.

Conservation Status

South Island takahe were thought to be extinct, with the last known specimens collected in 1898. However, careful surveys rediscovered this bird species in 1948 in the Murchison Mountains of South Island. South Island takahe are listed as endangered on the IUCN redlist. They have been the focus of major conservation and reintroduction efforts. South Island takahe populations have been established on 4 offshore islands where there are no invasive predators. Previously, hunting, loss of habitat, and introduced predators were the major factors contributing to population decline. Loss of habitat and introduced predators are still major factors, but additionally South Island takahe are threatened by lack of genetic diversity and the low fertility of these birds.

Other Comments

South Island takahe was formerly recognized as Porphyrio mantelli . It was later split into P. mantelli (extinct) and P. hochstetteri . This species is also commonly called "southern takahe." The extinct close relative, P. mantelli is also known as "North Island takahe."

Additional Links

Encyclopedia of Life

Contributors

Tanya Dewey (editor), Animal Diversity Web.

Jose Lara (author), Northern Michigan University, Alec R. Lindsay (editor, instructor), Northern Michigan University.

References

Baber, M., J. Craig. 2003. Home land range and carrying capacity of the South Island takahe ( Porphyrio hochstetteri) on Tiritiri Matagni Island. Notornis , 50: 67-74. Accessed April 10, 2008 at www.google.com/scholar .

Baillie, J., B. Groombridge. 2007. " Porphyrio hochstetteri " (On-line). IUCN Red List of Threatened Species. Accessed April 02, 2008 at http://www.iucnredlist.org/search/details.php/40130/summ .

Benstead, P., R. McClellan, J. Pilgrim. 2007. "Species factsheet: Porphyrio hochstetteri " (On-line). BirdLife International. Accessed April 18, 2008 at http://www.birdlife.org/datazone/species/?action=SpcHTMDetails.asp&sid=2929&m=0 .

Jamieson, I., C. Ryan. 2000. Increased egg infertility associated with translocating inbred takahe ( Porphyrio hochstetteri ) to island refuges in New Zealand. Biological Consevation , 94: 107-114. Accessed April 02, 2008 at www.google.com/scholar .

Ryan, C. 1997. Observations on the Breeding Behaviors of the Takahe ( Porphyrio mantelli ) on Manu Island. Nortonis , 44: 233-240. Accessed April 15, 2008 at www.google.com/scholar .

Wallace, G. 2002. The Takahe: Fifty Years of Conservation Management and Research. The Auk , 119/1: 291-293.

2005. "Kiwi Conservation Club" (On-line). The Takahe. Accessed April 12, 2008 at http://www.kcc.org.nz/birds/takahe.asp .