Phasianidae


Phasianidae is a family of heavy, ground-living birds, which includes pheasants, grouse, partridges, junglefowl, chickens, turkeys, Old World quail, and peafowl. The family includes many of the most popular gamebirds. The family includes 185 species divided into 54 genera. It was formerly broken up into two subfamilies, the Phasianinae and the Perdicinae. However, this treatment is now known to be paraphyletic and polyphyletic, respectively, and more recent evidence supports breaking it up into two subfamilies: Rollulinae and Phasianinae, with the latter containing multiple tribes within two clades. The New World quail and guineafowl were formerly sometimes included in this family, but are now typically placed in families of their own; conversely, grouse and turkeys, formerly often treated as distinct families, are now known to be deeply nested within Phasianidae, so they are now included in the present family.

Description

Phasianids are terrestrial. They range in weight from in the case of the king quail to in the case of the Indian peafowl. If turkeys are included, rather than classified as a separate family, then the considerably heavier wild turkey capably reaches a maximum weight of more than. Length in this taxonomic family can vary from in the king quail up to in green peafowl, thus they beat even the true parrots in length diversity within a family of birds. Generally, sexual dimorphism is greater in larger-sized birds, with males tending to be larger than females. They are generally plump, with broad, relatively short wings and powerful legs. Many have a spur on each leg, most prominently with junglefowl, pheasants, turkeys, and peafowl. Some, like quails, partridges, and grouse, have reduced spurs to none at all. A few have two spurs on each of their legs instead of one, including peacock-pheasants and spurfowl. The bill is short and compact, particularly in species that dig deep in the earth for food such as the Mearns quail. Males of the bigger galliform species often boast brightly-coloured plumage, as well as facial ornaments such as combs, wattles, and/or crests.

Distribution and habitat

The Phasianidae are mostly an Old World family, with a distribution that includes most of Europe and Asia, all of Africa except the driest deserts, and south into much of eastern Australia and New Zealand. The Meleagridini are native to the New World, while the Tetraonini are circumpolar; both of these are members of Phasianinae. The greatest diversity of species is in Southeast Asia and Africa. The Congo peacock is specific to the African Congo.
Overall, Rollulinae is restricted to the tropics of East and Southeast Asia and the mountains of Tanzania, Phasianinae have a circumpolar range in the temperate zones of both Eurasia and North America, and Pavoninae have a wide range across Africa, Eurasia, and Australasia in both temperate and tropical zones.
The family is generally sedentary and resident, although some members of the group undertake long migrations, like ptarmigans and Old World quail. Several species in the family have been widely introduced around the world, particularly pheasants, which have been introduced to Europe, Australia, and the Americas, specifically for hunting purposes. Captive populations of peafowl, pheasants, domestic chickens, and turkeys have also escaped or been released and became feral, intermingling and even hybridizing with wild populations.

Behaviour and ecology

The phasianids have a varied omnivorous diet, with foods consumed ranging from purely herbivorous selections of seeds, nuts, stems, leaves, shoots, flowers, fruits, bulbs, tubers, and roots, to carnivory including insects, larvae, slugs, spiders, reptiles, and even small mammals. Most species specialize either in feeding on plant matter or predating on tiny vertebrates, although the chicks of most species are insectivorous, preying on small invertebrates.
In addition to the variation in diet, a considerable amount of variation exists in breeding strategies among the Phasianidae. Compared to birds in general, a large number of species do not engage in monogamy. The francolins of Africa and some partridges are reportedly monogamous, but polygamy has been reported in the pheasants and junglefowl, some quail, and the breeding displays of peacocks have been compared to those of a lek. Nesting usually occurs on the ground; only the tragopans nest higher up in trees or stumps of bushes. Nests can vary from mounds of vegetation to slight scrapes in the ground. As many as 20 eggs can be laid in the nest, although 7–12 are the more usual numbers, with smaller numbers in tropical species. Incubation times can range from 14–30 days depending on the species, and is almost always done solely by the hen, although a few involve the male partaking in caring for the eggs and chicks, like the willow ptarmigan and bobwhite quail.

Relationship with humans

The red junglefowl of Southeast Asia is the wild ancestor of the domesticated chicken, the most important bird in agriculture, and the wild turkey similarly is the ancestor of the domestic turkey. Several species of pheasants and partridges are extremely important to humans. Ring-necked pheasants, several partridge and quail species, and some francolins have been widely introduced and managed as game birds for hunting. Several species are threatened by human activities.

Systematics and evolution

The clade Phasianidae is the largest of the branch Galliformes, comprising 185 species divided into 54 genera. This group includes the pheasants and partridges, junglefowl chickens, quail, and peafowl. Turkeys and grouse have also been recognized as having their origins in the pheasant- and partridge-like birds.
Until the early 1990s, this family was broken up into two subfamilies: the Phasianinae, including pheasants, tragopans, junglefowls, and peafowls; and the Perdicinae, including partridges, Old World quails, and francolins. Molecular phylogenies have shown that these two subfamilies are not each monophyletic, but actually constitute only one lineage with one common ancestor. For example, some partridges are more closely affiliated to pheasants, whereas Old World quails and partridges from the genus Alectoris are closer to junglefowls.
The earliest fossil records of phasianids date to the late Oligocene epoch, about 30 million years ago.

Recent genera

Taxonomy and ordering is based on Kimball et al., 2021, which was accepted by the International Ornithological Congress. Tribes and subfamily names are based on the 4th edition of the Howard and Moore Complete Checklist of the Birds of the World. Genera without a tribe are considered to belong to tribe incertae sedis.
This is the paraphyletic former ordering of Phasianidae, which primarily grouped genera based on appearance and body plans.
Extinct genus assignment follows the Mikko's Phylogeny Archive and Paleofile.com websites.
Cladogram based on a 2021 study by De Chen and collaborators that sequenced DNA flanking ultra-conserved elements. The extinct Himalayan quail was not included in the study. The species numbers and the inclusion of the genera Canachites, Ortygornis, Campocolinus and Synoicus follows the list maintained by Frank Gill, Pamela Rasmussen and David Donsker on behalf of the International Ornithologists' Union.