There are 13 or more subspecies of the purple swamphen (depending on the authority) which differ mainly in plumage colour. The subspecies groups are: P. p. porphyrio in the Mediterranean, P. p. madagascariensis in Africa, P. p. poliocephalus in tropical Asia,P. p. melanotus in much of Australasia, P. p. indicus in Indonesia and P. p. pulverulentis in the Philippines. European birds are overall purple-blue, African and south Asian birds have a green back, and Australasian and Indonesian birds have black backs and heads.
The nominate subspecies, P. p. porphyrio (Linnaeus, 1758), is found in Iberia, France, Sardinia and North Africa to Tunisia. P. p. madagascariensis (Latham, 1801) occurs in Egypt, sub-Saharan Africa and Madagascar, and resembles the nominate but with bronze green or green-blue back and scapulars. P. p. caspius (Hartert, 1917) from the Caspian Sea area, is like poliocephalus, but larger.
P. p. seistanicus (Zarudny & Harms, 1911) occurs from Iraq to Pakistan, as poliocephalus, but larger; smaller than caspius. P. p. poliocephalus (Latham, 1801) is found from India and Sri Lanka to south China and north Thailand, and has been introduced to Florida. It has cerulean blue scapulars, face throat and breast. P. p. indicus (Horsfield, 1821) occurs from Sumatra to Sulawesi and Bali, and has a large shield, black upperparts, and the side of the head is blackish. P. p. virdis (Begbie, 1834) occurs in South East Asia, and resembles indicus but the side of the head is cerulean blue. P. p. pulverulentus (Temminck, 1826) from the Philippines has olive-chestnut mantle and scapulars, and the whole plumage is tinged with ash-grey.
P. p. melanotus (Temminck, 1820) occurs in north and east Australia, New Zealand and the surrounding islands. It has a small shield, shorter toes, black upperparts, and a purple throat and breast. P. p. pelewensis (Hartlaub & Finsch, 1872) from Palau, resembles melanotus but has greener upperparts and is smaller. P. p. melanopterus (Bonaparte, 1856) is found from the Lesser Sundas and Moluccas to New Guinea. It is as melanotus but smaller, more variable and less blue in the upperparts. P. p. bellus(Gould, 1820) from West Australia is as melanotus but has a cerulean blue throat and breast. P. p. samoensis (Peale, 1848) occurs from New Guinea to New Caledonia and Samoa, and is as melanotus but smaller, with a brown tinge on the back.
Some authorities separate various subspecies as full species, for example P. p. madagascariensis is split by Sinclair et al. as African purple swamphen, P. madagascariensis.
The common name in New Zealand, used by Maori for the subspecies P. p. melanotus, is the Māori language name pūkeko. The New Zealand purple swamphen was held in high regard as a chiefly pet in New Zealand and in Samoa, where it is called "manuali'i" (literally, "chiefly bird"). Red was the prized color of Polynesian aristocracy and while birds with red plumage (such as the red-tailed tropicbird, some Hawaiian honeycreepers like the 'i'iwi' and maroon shining parrot) were highly prized, the swamphen was unique in deriving its prestige not from plumage but from its reddish face, beak, and legs. In old Samoa only chiefs could keep such birds as pets, and early European sailors noticed tethered and/or caged swamphens treated by Samoan chiefs as tamed pets. Some Samoans also considered the swamphen to be the incarnation of a mischievous, aggressive demon called Vave (Corey & Shirley Muse, "The Birds and Birdlore of Samoa," 1982). There is no tradition of swamphens being taken as sport game or poultry food, except perhaps in time of necessity.
The purple swamphen is occasionally recorded as an escape from captivity in Britain and elsewhere.
The purple swamphen was introduced to North America in the late 1990s due to avicultural escapes in the Pembroke Pines, Floridaarea. State wildlife biologists attempted to eradicate the birds, but they have multiplied and can now be found in many areas of southern Florida. Ornithological authorities consider it likely that the swamphen will become an established part of Florida's avifauna.It was added to the American Birding Association checklist in February 2013. These Florida birds are mostly or entirely of the gray-headed race poliocephalus, native to the area around the Caspian Sea.
The species is considered to be Least Concern globally by the IUCN. While the species as a whole is not threatened, some subspecies have declined. In New Zealand and Australia it has expanded due to the creation of new artificial lakes and ponds, but the nominate race in the Mediterranean has declined due to habitat loss, hunting and pesticide use, and requires strict protection. InPortugal the species declined greatly in the 19th and 20th centuries, but has increased more recently thanks to protection and some reintroduction schemes, although it remains rare and has a fragmented distribution.
In Africa it varies from being common to being uncommon. The subspecies endemic to Palau has been considered endangered as well, although a 2005 survey found that the subspecies, while potentially threatened, is at least now still common.
Pairs nest in a large pad of interwoven reed flags,
etc., on a mass of floating debris or amongst matted reeds slightly above water
level in swamps, clumps of rushes in paddocks or long unkempt grass. Multiple
females may lay in the one nest and share the incubation duties. Each
bird can lay 3–6 speckled eggs, pale yellowish stone to reddish buff,
blotched and spotted with reddish brown. A communal nest may contain up to 12
eggs. The incubation period is 23–27 days, and is performed by both sexes as
well as any helpers that might be present. The precocious chicks are
feathered with downy black feathers and able to leave the nest soon after
hatching, but will often remain in the nest for a few days. Young chicks are
fed by their parents (and group members) for between 10–14 days, after which
they begin to feed themselves.
Purple swamphens are generally seasonal breeders, but the season varies across their large range, correlating with peak rainfall in many places, or summer in more temperate climes. The purple swamphen breeds in warm reed beds. The male has an elaborate courtship display, holding water weeds in his bill and bowing to the female with loud chuckles. In the western parts of the range the pattern of social behaviour tends to be monogamy, but cooperative breeding groups are more common in the eastern parts of the range. These groups may consist of multiple females and males sharing a nest or a male female pair with helpers drawn from previous clutches.
The purple swamphen prefers wet areas with high rainfall, swamps, lake edges and damp pastures. The birds often live in pairs and larger communities. It clambers through the reeds, eating the tender shoots and vegetable-like matter. They have been known to eat eggs, ducklings, small fish and invertebrates such as snails. They have even been known to attack large eels, however there is no consensus amongst ornithologists if they actually eat eel. They will often use one foot to bring food to their mouth rather than eat it on the ground. Where they are not persecuted they can become tame and be readily seen in towns and cities.