![Male ring-necked pheasant (Phasianus colchicus torquatus).[Credits : Laurie Campbell—Stone/Getty Images]](http://media-2.web.britannica.com/eb-media/54/62554-003-858C5F55.gif)
![Blue, or Indian, peacock (Pavo cristatus) displaying its resplendent feathers.[Credits : © Digital Vision/Getty Images]](http://media-2.web.britannica.com/eb-media/88/92688-003-02149000.gif)
any of the gallinaceous (that is, fowl-like or chickenlike) birds. The order includes about 290 species, of which the best-known are the turkeys, chickens, quail, partridge, pheasant and peacock (Phasianidae); guinea fowl (Numididae); and grouse (Tetraonidae). Lesser-known members of the order are the megapodes and the chachalacas, guans, and curassows. Although the hoatzin is here treated with the Galliformes, most taxonomists have assigned the hoatzin to the family Opisthocomidae (order Cuculiformes).
![Body plans of galliform birds.[Credits : Encyclopædia Britannica, Inc.]](http://media-2.web.britannica.com/eb-media/94/52894-003-2AA2FAB2.gif)
Most galliforms are medium-sized birds, from the size of a pigeon to that of a domestic chicken, 40 to 60 cm (16 to 24 inches) long and 500 to 2,500 grams (1 to 5.5 pounds) in weight. The smallest members of the order are the sparrow-sized painted quail (Excalfactoria), about 13 cm (5 inches) long and about 45 grams (about 1.5 ounces) in weight. The heaviest galliform is the common, or wild, turkey (Meleagris gallopavo), wild specimens of which may weigh up to 11 kg (about 24 pounds); the longest is the argus pheasant (Argusianus argus), the male of which reaches 2 metres (79 inches) in breeding plumage, including wing and tail feathers, whose length exceeds one metre.
The majority of gallinaceous birds are heavy-bodied, with short, rounded wings and strong, four-toed feet, adapted for life on the ground; a few, such as cracids and the hoatzin, live mainly in trees. The bill is short and slightly downcurved. The flight is fast but rarely sustained for long distances, most galliforms being sedentary, nonmigratory birds.
Male-ring-necked-pheasantMale ring-necked pheasant (Phasianus colchicus torquatus).[Credits : Laurie Campbell—Stone/Getty Images]
Blue-or-Indian-peacock-displaying-its-resplendent-feathersBlue, or Indian, peacock (Pavo cristatus) displaying its resplendent feathers.[Credits : © Digital Vision/Getty Images]
British-white-turkeys-are-raised-for-their-meat-on-specializedBritish white turkeys are raised for their meat on specialized poultry farms.[Credits : Jim Corwin—Stone/Getty Images]
Body-plans-of-galliform-birdsBody plans of galliform birds.[Credits : Encyclopædia Britannica, Inc.]
Male-common-turkey-displayingMale common turkey (Meleagris gallopavo), displaying.[Credits : S.C. Bisserot—Bruce Coleman Inc.]
White-tailed-ptarmigan-as-winter-approaches-in-summerWhite-tailed ptarmigan (Lagopus leucurus), (top) as winter approaches, (bottom) in summer[Credits : (Top) Kenneth W. Fink from Root Resources, (bottom) C.A. Morgan]White-tailed ptarmigan (Lagopus leucurus), (top) as winter approaches, (bottom) in summer[Credits : (Top) Kenneth W. Fink from Root Resources, (bottom) C.A. Morgan]
Common-pheasantCommon pheasant (Phasianus colchicus)[Credits : H. Reinhard—Bruce Coleman Inc./EB Inc.]
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