Common pheasant

The common pheasant, ring-necked pheasant, or blue-headed pheasant, is a bird in the pheasant family. The genus name comes from Latin phasianus 'pheasant'. The species name colchicus is Latin for 'of Colchis', a country on the Black Sea where pheasants became known to Europeans. Although Phasianus was previously thought to be closely related to the genus Gallus, the genus of junglefowl and domesticated chickens, recent studies show that they are in different subfamilies, having diverged over 20 million years ago.
It is native to Asia, where it is widespread, and also the extreme southeast of Europe in the northern foothills of the Caucasus Mountains. It has been widely introduced elsewhere as a game bird. In parts of its range, mainly in places where none of its relatives occur such as in Europe, where it is naturalised, it is simply known as the pheasant. Ring-necked pheasant is both the collective name for a number of subspecies and their intergrades that have white neck rings, and the name used for the species as a whole in North America.
It is a well-known gamebird, among those of more than regional importance perhaps the most widespread and ancient one in the whole world. The common pheasant is one of the world's most hunted birds; it has been introduced for that purpose to many regions, and is also common on game farms where it is commercially bred. The ring-necked subspecies group in particular are commonly bred and were introduced to many parts of the world; the game farm stock, though no distinct breeds have been developed yet, can be considered semi-domesticated. The ring-necked pheasant is the state bird of South Dakota, one of only two US state birds that is not a species native to the United States.
The green pheasant of Japan is sometimes considered a subspecies of the common pheasant. Though the species produce fertile hybrids wherever they coexist, this is simply a typical feature among fowl, in which postzygotic isolating mechanisms are slight compared to most other birds. The species apparently have somewhat different ecological requirements and at least in its typical habitat, the green pheasant outcompetes the common pheasant. The introduction of the latter to Japan has therefore largely failed.

Description

There are many colour forms of the male common pheasant, ranging in colour from nearly white to almost black in some melanistic examples. These are due to captive breeding and hybridisation between subspecies and with the green pheasant, reinforced by continual releases of stock from varying sources to the wild. For example, the "ring-necked pheasants" common in Europe, North America and Australia do not pertain to any specific taxon, they rather represent a stereotyped hybrid swarm. Body weight can range from, with males averaging and females averaging. Wingspan ranges from.
The adult male common pheasant of the nominate subspecies Phasianus colchicus colchicus is in length with a long brown streaked black tail, accounting for almost of the total length. The body plumage is barred bright gold or fiery copper-red and chestnut-brown plumage with iridescent sheen of green and purple; but rump uniform is sometimes blue. The wing coverage is white or cream and black-barred markings are common on the tail. The head is bottle green with a small crest and distinctive red wattle. P. c. colchicus and some other races lack a white neck ring. Behind the face are two ear-tufts, that make the pheasant appear more alert.
The female and juveniles are much less showy, with a duller mottled brown plumage all over and measuring long including a tail of around. Juvenile birds have the appearance of the female with a shorter tail until young males begin to grow characteristic bright feathers on the breast, head and back at about 10 weeks after hatching.
The green pheasant is very similar, and hybridisation often makes the identity of individual farmed birds difficult to determine. Green pheasant males on average have a shorter tail than the common pheasant and have darker plumage that is uniformly bottle-green on the breast and belly; they always lack a neck ring. Green pheasant females are darker, with many black dots on the breast and belly.
In addition, various colour mutations are commonly encountered, mainly melanistic and flavistic specimens. The former are rather commonly released in some areas and are named "tenebrosus pheasant" or simply "melanistic mutant".

Taxonomy and systematics

This species was first scientifically described by Carl Linnaeus in his landmark 1758 10th edition of Systema Naturae under its modern scientific name. The common pheasant is distinct enough from any other species known to Linnaeus for a laconic rufus, capîte caeruleo, "a red pheasant with blue head", to serve as entirely sufficient description. The bird had been extensively discussed before Linnaeus established binomial nomenclature so was already well-known. His sources are the Ornithologia of Ulisse Aldrovandi, Giovanni Pietro Olina's Uccelliera, John Ray's Synopsis methodica Avium & Piscium, and A Natural History of the Birds by Eleazar Albin. Therein—essentially the bulk of the ornithology textbooks of his day—the species is simply named "the pheasant" in the books' respective languages. Whereas in most other species, Linnaeus felt it warranted to cite plumage details from his sources, in the common pheasant's case he simply referred to the reason of the bird's fame: principum mensis dicatur. The type locality is given simply as "Africa, Asia".
However, the bird does not occur in Africa, except perhaps in Linnaeus's time in Mediterranean coastal areas where they might have been introduced during the Roman Empire. The type locality was later fixed to the Rioni River in western Georgia, known as Phasis to the Ancient Greeks. These birds, until the modern era, constituted the bulk of the introduced stock in parts of Europe that was not already present; the birds described by Linnaeus's sources, though typically belonging to such early introductions, would certainly have more alleles in common with the transcaucasian population than with others. The scientific name is Latin for "pheasant from Colchis", colchicus referring to the west of modern-day Georgia; the Ancient Greek term corresponding to the English "pheasant" is Phasianos ornis, "bird of the river Phasis". Although Linnaeus included many Galliformes in his genus Phasianius such as the domestic chicken and its wild ancestor the red junglefowl, only the common and the green pheasant have since been placed in this genus. As the latter was not known to Linnaeus in 1758, the common pheasant is treated as the type species of Phasianus.
In the US, common pheasants are widely known as "ring-necked pheasants". One North American writer called them "chinks" or, in Montana, "phezzens". In China, meanwhile, the species is properly called zhi ji, "pheasant-fowl", essentially implying the same as the English name "common pheasant". As elsewhere, P. colchicus is such a familiar bird in China that it is usually just referred to as shan ji, "mountain chicken", a Chinese term for pheasants in general.
As of 2005, it had the smallest known genome of all living amniotes, only 0.97 pg, roughly one-third of the human genome's size; however, the black-chinned hummingbird has the smallest known amniote genome.

Subspecies

There are about 30 subspecies in five to eight groups. These can be identified by the male plumage, namely presence or absence of a white neck-ring and/or a white superciliary stripe, the colour of the uppertail and wing coverts, and the colour of crown, chest, upper back, and flank feathers. As noted earlier, introduced populations have mixed the alleles of various races, differing according to the original stock used for introductions and what natural selection according to climate and habitat has made of that.
An investigation into the genetic relationships of subspecies suggested that the common pheasant originated from the forests of southeastern China. Initial divergence is thought to have occurred around 3.4 Mya. The lack of agreement between morphology-based subspecies delimitation and their genetic relationships is thought to be attributed to past isolation followed by more recent population mixing as the pheasant has expanded its range across the Palaearctic.
Sometimes this species is split into the Central Asian common and the East Asian ring-necked pheasants, roughly separated by the arid and high mountainous regions of Turkestan. However, while the western and eastern populations probably were entirely separate during the Zyryanka glaciation when deserts were more extensive, this separation was not long enough for actual speciation to occur. The largest variety of colour patterns is found where the western and eastern populations mix, as is to be expected. Females usually cannot be identified even to subspecies group with certainty.
Many subspecies are in danger of disappearing due to hybridisation with introduced birds. The last black-necked pheasant population in Europe survives in Greece in the delta of the river Nestos, where in 2012 the population was estimated 100–250 individuals.
The subspecies groups, going from west to east, and some notable subspecies are:

Subspecies	Range	Description	Image
WESTERN CLADE – Red-rumped pheasants:		The lower back, rump, and upper tail-coverts are of a bronze-red, maroon, or rusty-orange general colour, sometimes glossed with oily green; black bars on the tail generally narrow.
P. c. colchicus group – Black-necked pheasants: P. c. colchicus, P. c. septentrionalis, P. c. talischensis, P. c. persicus	Caucasus to W. Turkestan; early introduced into Turkey and Greece	No neck ring. Wing coverts buff to brown, uppertail coverts rusty to chestnut
P. c. chrysomelas / P. c. principalis group – White-winged pheasants: P. c. principalis, P. c. zarudnyi, P. c. zerafschanicus, P. c. bianchii, P. c. chrysomelas, P. c. shawii	Central Turkestan and western Tarim Basin	No or vestigial neck ring. Wing coverts whitish, uppertail coverts and general plumage hue bronze to brown
P. c. mongolicus group – Kyrghyz pheasants: P. c. turcestanicus, P. c. mongolicus	NE Turkestan and adjacent Xinjiang. Despite its name, P. c. mongolicus does not occur in Mongolia.	Broad neck ring. Wing coverts white, uppertail coverts hue rusty to chestnut, general plumage hue copper
P. c. tarimensis group – Tarim pheasants: P. c. tarimensis	SE Turkestan around the eastern Tarim Basin	No or vestigial neck ring. Wing coverts buff to brown, uppertail coverts dark khaki to light olive
EASTERN CLADE – Grey-rumped pheasants:		The lower back, rump, and upper tail-coverts are of a light and more or less lavender-blue, greenish- or yellowish-grey, or olive-greenish colour; a rusty orange patch on each side of the rump; black tail-bars generally broad.
P. c. elegans group – Yunnan pheasants: P. c. elegans, P. c. rothschildi	Eastern Tibet, western Sichuan, northwestern and southeastern Yunnan, northwestern Vietnam and northern Myanmar.	White neck collar and orbital lines are absent. A broad band of richly glossed dark green or bluish green colour runs down the underparts, completely separating the brassy-chestnut of the sides of the chest. Crown dark green. Uppertail coverts light bluish grey.
P. c. strauchi / P. c. vlangalii group – Western grey-rumped pheasants: P. c. suehschanensis, P. c. vlangalii, P. c. satscheuensis, P. c. edzinensis, P. c. strauchi, P. c. sohokhotensis, P. c. alaschanicus, P. c. kiangsuensis	Qaidam Basin, eastern Qinghai, northeastern Sichuan, Inner Mongolia, Gansu, Ningxia, Shanxi, Shaanxi, western Hebei. Note that, despite its name, P. c. kiangsuensis does not occur in Jiangsu.	The white neck collar and orbital lines are usually either absent or rather narrow, often not complete. Brassy-chestnut on chest dominating over glossy green colour. Crown usually dark green.
P. c. torquatus group – Chinese ring-necked pheasants: P. c. hagenbecki, P. c. pallasi, P. c. karpowi, P. c. torquatus, P. c. takatsukasae, P. c. decollatus	Widespread in eastern China, extending to northernmost Vietnam in the south and to the Strait of Tartary region in the north; with an isolated population in north-western Mongolia. Absent from Hainan. Most pheasants introduced in North America are of this group.	White neck ring varies from broad in the north east to absent in the south west. Wing coverts tan to light grey. Chest copper red to light brown red, in P. c. decollatus rich purple red with thick black feather margins. Crown varying from dark green without orbital lines to light grey framed with white orbital lines. In P. c. hagenbecki chest feathers broadly fringed black.
P. c. formosanus group – Taiwan pheasants: P. c. formosanus	Taiwan	White neck ring interrupted at front neck. Flank feathers characteristically whitish or pure white with black apices and often narrow black margins. Feathers at chest broadly fringed black, giving a scaly appearance.
Subspecies:
P. c. pallasi	Southeastern Siberia, adjacent northeastern North Korea to northeastern China	Plumage dominated by yellow and copper brown tones. Greyish green crown, framed by white orbital lines. White collar very wide and uninterrupted, often broader at the front.
P. c. karpowi	Northeastern China and central and southern Korea and Jeju Island in South Korea. Introduced on Hokkaido, Japan.	Darker and more richly coloured than P. c. pallasi, and white collar narrower.
P. c. elgans	Eastern Tibet, Western Sichuan, and Northwestern Yunnan provinces, 1,500–3,000 m preferred elevation.	Overall plumage dark and contrasting, but check to distinguish this subspecies from P. c. suehschanensis which has some range overlap. Scaplulars are scarcely spotted when compared to those of P. c. suehschanensis.
P. c. decollatus	Central China.	Appears like P. c. torquatus but with no collar
P. c. takatsukasae	Southeastern China and Tonkin	Poorly known, best identified by range. Supposedly similar to P. c. torquatus but overall darker.
P. c. rothschildi	Yunnan, Tonkin, northern Laos and eastern Myanmar. Prefers elevations of 1,500 to 3,000 m	Similar to P. c. elegans but lighter. Best identified by range
P. c. torquatus	Eastern China
P. c. formosanus	Taiwan	Black belly and pale sides. Range is also diagnostic.
P. c. alaschanicus	North Central China, Southern Mongolia. "Oases near the western foothills of Ala-Shans".	Poorly known, best identified by range.
P. c. hagenbecki	Kobdo Valley, Mongolia, prefers elevations of 1,000 to 1,500 m	Distinctive bright golden flanks as well as small range are diagnostic.
P. c. kiangsuensis	Northeastern China	Extremely similar P. c. torquatus, range overlaps, but P. c. kiangsuensis skews further north. The barring on the nape in finer in P. c. kiangsuensis than in P. c. torquatus.
P. c. satscheuensis	Northwestern Gansu	Best identified by range
P. c. strauchi	Central China, Gansu south to Szechuan. Prefers altitudes near 3,000 m	Extremely variable, best identified by range and elimination of other subspecies.
P. c. suehschanensis	Northwest Szechuan and Eastern Tibet	Similar to elegans
P. c. vlangallii	Quinghai, prefers elevations of 600 to 2,100 m	Best identified by range
P. c. edzinensis	Ruo Shui basin	Similar plumage to P. c. satscheuensis, best identified by range.
P. c. sohokhotensis	Sohokhoto Oasis	Resembles P. c. strauchi but paler with "eyebrows" and a collar.
P. c. tarimensis	Southeastern Tarim Basin	Olive-green rump
P. c. mongolicus	Northern Kyrgyzstan, Eastern Kazakhstan, Xinjiang and Urumchi.	Widespread in its range. Darkly plumaged with contrasting white wing coverts.
P. c turcestanicus	Syr Darya river valley	Small range, darkly plumaged with contrasting white wing coverts, slightly brighter sides than P. c. mongolicus.
P. c. bianchii	Southern Uzbekistan, southwestern Tajikistan and extreme northern Afghanistan	Bright white wing coverts, also use range.
P. c. principalis	Southeastern Turkmenistan, extreme northern Iran and Afghanistan	Rare, identification information poorly known other than range, look for the contrasting green and purple-maroon throat.
P. c. shawii	Xinjiang	Bright white wing coverts
P. c. zerafschanicus	Bukhara, Zeravshan and Kashkadarya Valleys of Southern Uzbekistan.	Best identified by range
P. c. zarudnyi	Central valleys of the river Amu Darya on the eastern Turkmenistan–Uzbekistan border.	Best identified by range and glossy-green throat.
P. c. colchicus	Northeasternmost Turkey to eastern Georgia, eastern Azerbaijan, Dagestan, Armenia and northwestern Iran.	The most widespread of the "black-necked pheasants". Commonly released as a gamebird. Possibly the ancestral population of the "old English pheasant"
P. c. septentrionalis	Dagestan to north of the Volga Delta	Large, white spots on the back. Golden-orange nape that contrasts against the dark rump.
P. c. talischensis	Transcaucasia and Caspian lowlands of Iran	Fine, even white spots on the back, overall warm orange plumage, little contrast of wing plumage. Range important for identification.
P. c. persicus	Southwest Turkmenistan and northcentral Iran	Overall warm orange plumage, wing plumage bright white and contrasting.

Within a maximum clade credibility mDNA gene tree, the most basal group is the P. c. elegans-group of the Eastern Clade, diverging from the green pheasant during the Calabrian, and diversifying in Middle Pleistocene around 0.7 million years ago, with the groups of the Western Clade splitting off from those of the Eastern Clade about 0.59 million years ago. While the subspecies of the Western Clade are well geographically separated from each other, the subspecies of the Eastern Clade often show clinal variation and large areas of intergradation. For example, clines connect P. c. pallasi-karpowi-torquatus-takatsukasae within the P. c. torquatus group and P. c. kiangsuensis-alaschanicus-sohokhotensis-strauchi within the P. c. strauchi-vlangalii group, with the degree of expression of white collar and superciliary stripe in both cases decreasing from north to south. The isolated form P. c. hagenbecki is very close to P. c. pallasi in phenotype, and has been traditionally treated within the P. c. torquatus group until recently, when it was assigned in one study to the P. c. strauchi / P. c. vlangalii group. However, the origin of the corresponding feather samples as listed in GenBank is far away from the known distribution of subspecies P. c. hagenbecki, and the issue needs further clarification.