Porphyrio porphyrio

Porphyrio porphyrio

The Western Swamphen or Purple Swamphen (Porphyrio porphyrio Linnaeus, 1758) is a bird belonging to the Rallidae family.

Systematics –
From a systematic point of view it belongs to:
Eukaryota domain,
Kingdom Animalia,
Subkingdom Eumetazoa,
Bilateria branch,
Phylum Chordata,
Subphylum Vertebrata,
Infraphylum Gnathostomata,
Superclass Tetrapoda,
(clade) Amniota,
Aves class,
Subclass Neornithes,
Superorder Neognathae,
Order Gruiformes,
Rallidae family,
Genus Porphyrio,
P. porphyrio species.
The term is basionym:
– Fulica porphyrio Linnaeus, 1758;
The term is synonymous:
– Gallinula porphyrio Linnaeus, 1758.
The following subspecies are recognized within this species:
– Porphyrio porphyrio subsp. bellus Gould, 1841;
– Porphyrio porphyrio subsp. caspius Hartert, 1917;
– Porphyrio porphyrio subsp. indicus Horsfield, 1821;
– Porphyrio porphyrio subsp. madagascariens (Latham, 1801);
– Porphyrio porphyrio subsp. madagascariensis (Latham, 1802);
– Porphyrio porphyrio subsp. melanopterus Bonaparte, 1856;
– Porphyrio porphyrio subsp. melanotus Temminck, 1820;
– Porphyrio porphyrio subsp. nujagura Boles & Backness, 1994;
– Porphyrio porphyrio subsp. pelewensis Hartlaub & Finsch, 1872;
– Porphyrio porphyrio subsp. poliocephalus (Latham, 1802);
– Porphyrio porphyrio subsp. porphyrio;
– Porphyrio porphyrio subsp. pulverulentus Temminck, 1826;
– Porphyrio porphyrio subsp. samoensis Peale, 1848;
– Porphyrio porphyrio subsp. seistanicus Zarudny & Harms, 1911;
– Porphyrio porphyrio subsp. viridis Begbie, 1834.

Geographic Distribution and Habitat –
The Porphyrio porphyrio is a widespread bird in Eurasia and North Africa even if some specimens have been exported to other countries where they have often escaped breeding.
It is found in the wetlands of Spain (where the largest population lives), Portugal, southeastern France, Italy (Sardinia and Sicily), and northwestern Africa (Morocco, Algeria and Tunisia).
In Spain, the subspecies Porphyrio porphyrio porphyrio inhabits all the Mediterranean and Atlantic coasts, in particular in the Doñana park and to a lesser extent in the wetlands of the Valencian community, where it has been almost completely expelled from the territories due to urban pressure.
In Sardinia it is present in the Molentargius pond. Until now considered sedentary, it seems that it is a partial migratory.
Worldwide, populations are in a state of distress due to the loss of wetlands and contamination of domesticated animals, although it is still classified as a species of low concern.
Its habitat is typically that of inland and coastal wetlands, lakes, artificial reservoirs, marshes, even temporary ponds, reclamation and irrigation canals, constructed wetlands and river channels.

Description –
Porphyrio porphyrio is a rather large and stocky bird, about 40–55 cm long and with a wingspan of 90–100 cm.
It has a large red triangular beak surmounted by a frontal shield of the same color; the legs are variable in color from red to pinkish-red with long, thin toes and red iris.
The color of the plumage is very variable; the upper regions and wings are dark blue-purple, the undertail feathers are white. The sexes are similar but with the females being smaller, and also having less pronounced frontal scutes. Males weigh 720-1000 g and females 520-870 g.
The young specimens are similar to the adults, but have less showy plumage; some specimens maintain the juvenile livery even in adulthood. The juveniles of the nominate subspecies have the face, the anterior part of the neck and the chest of a light gray colour, while the throat is almost white; the coloring of the wings is identical to that of the adult specimens, but the areas of bare skin are of a more faded colour.

Biology –
The Porphyrio porphyrio generally has a well-defined reproductive season, but within its vast range the period varies from one zone to another, in correlation with the rain peak in most localities, or in summer in zones with a more temperate. The pattern of social behavior tends to be monogamy.
It builds its nest in the thick reeds.
The male performs an elaborate courtship ritual, picking tufts of aquatic weeds in his beak and bowing to his mate, all while emitting shrill calls.
In the western regions of the range the individuals tend to have monogamous habits, whilst in the eastern regions community nesting in groups is very practiced. In the latter case, these groups may consist of several specimens of both sexes sharing a common nest or of “extended” families also including “helpers” belonging to previous broods.
About two weeks after the start of courtship, the pairs begin to build the nest by arranging different plants in piles and then fixing them to stems of aquatic plants, so as to anchor it and also to camouflage it. The nest has a diameter of 25 cm and is even 50 cm tall and ends with a 5–8 cm high roof. Sideways they build a 5–6 cm walkway which leads almost at right angles into the nest. Sometimes the walkway, also formed of plants arranged in piles, can extend for 25 cm into the thick vegetation, so that it can be used by the parents to leave the nest unnoticed in case of danger.
Several females can spawn in the same nest and share incubation duties.
Each bird can lay 3-6 eggs ranging in color from yellowish-grey to reddish-buff, covered with reddish-brown specks. A community nest can contain up to 12 eggs.
Incubation lasts 23-27 days, and is carried out by both parents, as well as helpers, if they are present. The precocious chicks are covered with a thick black down and are able to leave the nest shortly after the eggs have hatched, although they often spend the first few days in the nest.
The chicks are fed by both parents (and all members of the flock) for 10-14 days, after which they begin to forage on their own.

Ecological Role –
The Porphyrio porphyrio is a wary bird that remains hidden in the thick vegetation, mainly emerging from sunset to sunrise. However, it can be observed in the open even in broad daylight, provided that it is in quiet areas. It can also be detected by its characteristic voice resembling the sound of a trumpet.
It feeds mainly on aquatic plants but also on small animals such as molluscs and insects. In detail, they feed on flowers and leaves of aquatic plants and climb trees to eat their berries, especially mulberries. They also eat molluscs, crustaceans and other small animals that they find on plants in shallow waters. The study of diet is partly facilitated by the fact that they build “feeding platforms”, made up of plants, which are very often found covered by the remains of their meals. It is not known whether all individuals build these “feeding platforms” for themselves, but it is certain that those in southern Spain and Western Australia do. These birds often feed on tadpoles and aquatic insects; moreover, snail shells have often been found. Finally, bloodstains indicate that these animals also feed on leeches. It is known that in southern Spain they also feed on water snakes.
The species emits loud, rapid, bleating and whistling calls that are unlikely to resemble those of birds in tone. It is especially noisy during the breeding season. Although clumsy in flight, it can travel long distances and is a good swimmer, especially for a bird without webbed feet.
According to what Pliny the Elder and other Latin writers tell, it would seem that the rich Romans kept specimens of this bird as ornamental species in the largest villas and luxurious homes. At the time this species was considered a noble bird and was among the few species of birds that the Romans did not eat.
The specimens of the subspecies P. p. melanotus were held in high esteem by the inhabitants of New Zealand (where they are still called by the Māori name of pūkeko) and Samoa (where they are called manual’i, literally «main birds»), and in both localities they were kept as pets. Red was the most prized color of the Polynesian aristocracy, and unlike other birds with red body patches (such as the red-tailed tropicbird, some Hawaiian tree drepanids, such as the i’iwi, and the red resplendent parrot), this species it was the only one not to have red feathers, but the face, beak and legs. In Samoa, in the past, only the tribal chiefs could keep specimens as pets, and the first European sailors who arrived there noticed birds of this type, tied or kept in cages, considered as real pets. Some Samoans also considered this bird to be the incarnation of an aggressive and mischievous demon called the Vave. There is no evidence of specimens considered as game or poultry animals, with the exception, perhaps, of periods of greatest need.
Some specimens, introduced into the Pembroke Pines area in the late 1990s, got out of control, subsequently settling in many areas of southern Florida, where they are now considered a stable element of the local avifauna. The species was officially listed on the American Birding Association Checklist in February 2013.
On the IUCN Red List, Porphyrio porphyrio is listed among the least endangered species (Least Concern). In the Mediterranean region, the species is declining as a result of habitat loss, hunting and the use of pesticides, and is in need of particular protection. In Portugal it had almost disappeared during the 19th and 20th centuries, but lately, thanks to the protection granted and to some reintroduction programs, it has increased again, even if it remains rare and with a fragmented distribution.
In some countries, its worst enemies are poaching and land reclamation. In Sardinia it is a strictly protected species (L.R. of Sardinia 32/78).

Guido Bissanti

Sources
– Wikipedia, the free encyclopedia.
– GBIF, the Global Biodiversity Information Facility.
– C.Battisti, D. Taffon, F. Giucca, 2008. Atlas of nesting birds, Gangemi Editore, Rome.
– L. Svensson, K.Mullarney, D. Zetterstrom, 1999. Guide to Birds of Europe, North Africa and the Near East, Harper Collins Publisher, UK.

Photo source:
– https://inaturalist-open-data.s3.amazonaws.com/photos/255593768/original.jpg