The Pheasant Pigeon is a large terrestrial

Terrestrial animal

Terrestrial animals are animals that live predominantly or entirely on land , as compared with aquatic animals, which live predominantly or entirely in the water , or amphibians, which rely on a combination of aquatic and terrestrial habitats...

 pigeon found in the primary rainforest

Rainforest

Rainforests are forests characterized by high rainfall, with definitions based on a minimum normal annual rainfall of 1750-2000 mm...

s of New Guinea

New Guinea

New Guinea is the world's second largest island, after Greenland, covering a land area of 786,000 km2. Located in the southwest Pacific Ocean, it lies geographically to the east of the Malay Archipelago, with which it is sometimes included as part of a greater Indo-Australian Archipelago...

 and nearby islands. It ranges primarily over hilly and lower mountain areas, but can also be found in lowland

Lowland

In physical geography, a lowland is any broad expanse of land with a general low level. The term is thus applied to the landward portion of the upward slope from oceanic depths to continental highlands, to a region of depression in the interior of a mountainous region, to a plain of denudation, or...

s.

The pheasant pigeon is an unusual pigeon of uncertain affinities within the Columbidae, and is monotypic within the genus

Genus

In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 Otidiphaps (Gould

John Gould

John Gould was an English ornithologist and bird artist. The Gould League in Australia was named after him. His identification of the birds now nicknamed "Darwin's finches" played a role in the inception of Darwin's theory of evolution by natural selection...

, 1870), and the sub-family Otidiphabinae. Its scientific name makes reference to its similarities to the bustard

Bustard

Bustards, including floricans and korhaans, are large terrestrial birds mainly associated with dry open country and steppes in the Old World...

 family (Otidae). Its common name reflects its adaptation to living on the forest floor in the fashion of a South East Asian pheasant

Pheasant

Pheasants refer to some members of the Phasianinae subfamily of Phasianidae in the order Galliformes.Pheasants are characterised by strong sexual dimorphism, males being highly ornate with bright colours and adornments such as wattles and long tails. Males are usually larger than females and have...

, which it resembles in external morphology

Morphology (biology)

In biology, morphology is a branch of bioscience dealing with the study of the form and structure of organisms and their specific structural features....

, particularly in its laterally compressed tail and the rounded wings. No galliform

Galliformes

Galliformes are an order of heavy-bodied ground-feeding domestic or game bird, containing turkey, grouse, chicken, New and Old World Quail, ptarmigan, partridge, pheasant, and the Cracidae. Common names are gamefowl or gamebirds, landfowl, gallinaceous birds or galliforms...

 birds occur in New Guinea, and the pheasant pigeon has filled the ecological niche

Ecological niche

In ecology, a niche is a term describing the relational position of a species or population in its ecosystem to each other; e.g. a dolphin could potentially be in another ecological niche from one that travels in a different pod if the members of these pods utilize significantly different food...

 of a partridge

Partridge

Partridges are birds in the pheasant family, Phasianidae. They are a non-migratory Old World group.These are medium-sized birds, intermediate between the larger pheasants and the smaller quails. Partridges are native to Europe, Asia, Africa, and the Middle East...

 or small pheasant (while the larger Goura

Goura (genus)

The genus Goura consists of three species of crowned pigeons. They are the largest non-extinct members of the pigeon family. The three crowned pigeons are alike and replace each other geographically. The genus was described by James Francis Stephens in 1819.The phylogeny of the crowned pigeons is...

crowned pigeons have a lifestyle similar to larger pheasants, grouse

Grouse

Grouse are a group of birds from the order Galliformes. They are sometimes considered a family Tetraonidae, though the American Ornithologists' Union and many others include grouse as a subfamily Tetraoninae in the family Phasianidae...

 or turkey

Turkey (bird)

A turkey is a large bird in the genus Meleagris. One species, Meleagris gallopavo, commonly known as the Wild Turkey, is native to the forests of North America. The domestic turkey is a descendant of this species...

s). It is a highly secretive species, feeding on seeds and fallen fruit

Fruit

In broad terms, a fruit is a structure of a plant that contains its seeds.The term has different meanings dependent on context. In non-technical usage, such as food preparation, fruit normally means the fleshy seed-associated structures of certain plants that are sweet and edible in the raw state,...

s. It nests on the ground below trees and bushes, laying one egg

Egg (biology)

An egg is an organic vessel in which an embryo first begins to develop. In most birds, reptiles, insects, molluscs, fish, and monotremes, an egg is the zygote, resulting from fertilization of the ovum, which is expelled from the body and permitted to develop outside the body until the developing...

 that it incubates for around 4 weeks.

There are four subspecies

Subspecies

Subspecies in biological classification, is either a taxonomic rank subordinate to species, ora taxonomic unit in that rank . A subspecies cannot be recognized in isolation: a species will either be recognized as having no subspecies at all or two or more, never just one...

, which differ primarily in the presence or absence of a small crest and in the colour of the nape

Nape

The nape is the back of the neck. In technical anatomical/medical terminology, the nape is referred to by the word nucha, which also gives the adjective corresponding to "nape" in English, "nuchal"....

. The two best known are the western nominate (O. n. nobilis) with a greenish nape and O. n. aruensis from the Aru Islands

Aru Islands

The Aru Islands are a group of about ninety-five low-lying islands in the Maluku province of eastern Indonesia. They also form a regency of Indonesia.-Geography:...

 with a white nape. The two remaining subspecies, O. n. cervicalis from the eastern part of its range and O. n. insularis from Fergusson Island

Fergusson Island

Fergusson Island is the largest island of the D'Entrecasteaux Islands, in Papua New Guinea. It has an area of just over 500 square miles , and mostly consists of mountainous regions, covered by rain forests...

, have a grey nape and a black nape (concolour with the remaining black neck) respectively.

It is not considered threatened, although it has become locally extinct

Extinction

In biology and ecology, extinction is the end of an organism or of a group of organisms , normally a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and recover may have been lost before this point...

in some areas. Because it is tied to primary forests, and is unique within the pigeon family, it is considered a species that requires further investigation and monitoring.