Common pheasant

The common pheasant, known scientifically as Phasianus colchicus, is a highly recognizable bird in the pheasant family, Phasianidae.

It is often called the ring-necked pheasant, a name used for the species throughout North America. In China, the bird is known as zhi ji, or pheasant-fowl. This species is famous as a gamebird and is one of the most hunted birds in the world.

Because of its popularity for hunting, humans have introduced the pheasant to many regions across the globe. It is so widespread that it has become naturalized in parts of Europe. In South Dakota, the ring-necked pheasant serves as the state bird, making it one of only two US state birds not native to the United States.

Physically, the common pheasant shows extreme sexual dimorphism, meaning males and females look very different.

Adult males are incredibly colorful, with plumage that can range from nearly white to almost black in melanistic forms. The nominate subspecies, Phasianus colchicus colchicus, features a body of bright gold, fiery copper-red, or chestnut-brown. These feathers often have an iridescent sheen of green and purple. The male has a bottle-green head, a small crest, and a distinctive red wattle. A long, brown, streaked black tail often makes up almost half of its total length.

In contrast, females and juveniles are much less showy. They possess dull, mottled brown plumage to help them stay hidden. A male typically reaches a length of 50 to 70 centimeters, while females are generally smaller.

The biological history of the pheasant reveals complex evolutionary relationships.

While scientists once believed pheasants were closely related to the genus Gallus, which includes chickens, recent studies show they belong to different subfamilies. These groups diverged from a common ancestor over 20 million years ago. The species is also related to the green pheasant (P. versicolor) of Japan. Although these two species can produce fertile hybrids, they have different ecological requirements. In Japan, the green pheasant often outcompetes the common pheasant in its typical habitat, which has caused the introduction of the common pheasant to largely fail there.

Carl Linnaeus first provided a scientific description of the species in 1758.

He used the name Phasianus colchicus, which translates to "pheasant from Colchis." Colchis is an ancient name for the region of modern-day Georgia near the Black Sea. Linnaeus's description was brief, noting it as a red pheasant with a blue head. While he initially listed its location as "Africa, Asia," the type locality was later fixed to the Rioni River in western Georgia. This region is where the name Phasianos ornis, meaning "bird of the river Phasis," originated in Ancient Greek.

There is significant diversity within the species, with approximately 30 subspecies organized into several groups.

These subspecies are often categorized into western and eastern clades. The western clade includes red-rumped pheasants, such as the black-necked pheasant group. These birds may have bronze-red or rusty-orange rumps. The eastern clade consists of grey-rumped pheasants, which feature lavender-blue or olive-greenish rumps. Scientists believe the common pheasant originally evolved in the forests of southeastern China. Genetic evidence suggests the initial divergence of these groups occurred around 3.4 million years ago.

Genetic studies have also revealed interesting facts about the pheasant's biology.

As of 2005, the common pheasant was noted for having one of the smallest known genomes among all living amniotes. Its genome size is approximately 0.97 picograms, which contains about 970 million base pairs. This is roughly one-third the size of a human genome. However, it is not the absolute smallest, as the black-chinned hummingbird holds that record. This compact genetic makeup is a notable feature of the species' biological profile.

Today, the common pheasant remains a central figure in both natural ecosystems and human industry.

They are widely bred on commercial game farms, where the stock is considered semi-domesticated. However, the natural diversity of the species faces challenges. Many subspecies are at risk of disappearing due to hybridization with introduced birds. For example, the last population of black-necked pheasants in Europe was estimated to be only 100 to 250 individuals in the Nestos River delta as of 2012. This highlights the delicate balance between the pheasant's global success and the survival of its unique local varieties.