They display phenotypic characteristics typical of rails: relatively short wings and strong, elongated bills, adapted to its semi-aquatic lifestyle in wetlands.
[2] It is often found in swamps, marshes, and other wet lowland areas, though its habitat has expanded to include pastures, roadside verges, and farmland, due to significant landscape changes in New Zealand over the last 150 years.
[3] Its diet reflects this adaptability, consisting primarily of plant material such as grass stems, shoots, and leaves, but also including animal matter like invertebrates and, occasionally, the young of other bird species.
[7] Studies suggest that the Porphyrio clade originated in Africa during the Middle Miocene, about 10 million years ago (mya), with a single colonisation of the Americas and several dispersals into Southeast Asia and the Indo-Pacific.
[7] Porphyrio melanotus is believed to have arrived in Australasia within the past 600,000 years; however, bone deposits suggest a more recent presence on certain remote islands.
[7] Australasian swamphen are long-legged birds, standing about 51 cm tall, with dark plumage, black upper-parts, and a contrasting white undertail.
Although it is thought that P. porphyrio subspecies rarely use flight, this lineage has effectively dispersed, colonised, and established populations numerous times across extensive bodies of water.
[11] The Australasian swamphen has five subspecies distributed as follows:[12] The pūkeko, now widespread across mainland and offshore New Zealand, is thought to have been self-introduced from Australia about 1,000 years ago.
[7] However, Māori from the east coast hold the belief that their ancestors brought the pūkeko to New Zealand aboard the vessel Horouta, which arrived from Polynesia approximately twenty-four generations ago.
[14] In New Zealand, these birds thrive in wet lowlands and breed in swamps, but they also utilise a variety of habitats such as pastures, crops, farm ponds, road verges, and forest margins.
[3] Typically found in low-lying wetlands with vegetation like flax, raupo, and rushes, the swamphen is also common in estuaries, salt marshes, and along riverbanks.
[8] Their foraging activities can sometimes result in the uprooting of vegetation, including tree seedlings and crops, which has led to pūkeko being culled under permit in certain areas.
[16] Though considered native to New Zealand as a self-introduced species, pūkeko are unique in their dual role as both predators of young birds and crop foragers, a behaviour that occasionally places them in conflict with agricultural interests.
[19] In New Zealand they nest, typically well hidden in the middle of a clump of raupō, between August (end of winter) and March (start of autumn).
[2][19] Courting behaviour, such as preening and feeding, often appear symbolic, with the passing of food, such as small pieces of duckweed, occurring in a head-bow posture, typically from male to female but sometimes reversed.
[19] Another study claims that all males in a group contribute equally to parental care, probably due to the fact that there is no precise estimate of their share of paternity and they are unable to recognise their own young.
When threatened by predators such as harriers (Circus approximans), pūkeko display protective behaviour by forming compact groups in an alert posture, emitting harsh alarm calls while some individuals may fly up to confront the threat.
[8] The network structure of dominance relationships within groups is influenced by sexual homophily, indicating that same-sex individuals often compete for breeding positions.
[14] Socially dominant individuals enjoy priority access to resources and play different roles in parental care and territory defence compared to their subordinate counterparts.
Studies show that reasons for this behaviour include food sources such as invertebrates struck by vehicles and grass shoots from the mown verge, as well as grit for digestion in the gizzard.
It is said to have originated from the heavens, with the legendary figure Tāwhaki encountering the bird on its descent to Earth, searching for cooler waters due to the heat of the sun.
[8] As European settlers cleared forests and converted the land into farmland, pūkeko flocks shifted to targeting grain and vegetable crops while also foraging for worms and grass grubs in damp pastures.
When the pūkeko was born, Tāwhaki (Punga's brother) claimed it as an adopted son, marking its forehead with his blood as a sign of their relationship.
In New Zealand, pūkeko are protected as native gamebirds, meaning they may be hunted only under licence (from Fish and Game) during the duck shooting season.
Due to their foraging habits, they are occasionally culled under permit, even though there is limited understanding of how this practice impacts pūkeko populations and the broader ecosystem.
Hair-like nooses (made from cabbage tree fibre) were then dangled at the appropriate height, from the flax string, to catch pūkeko as they fed after dusk, in the low light conditions.