Guinea fowl are seven species of medium-sized terrestrial birds in the family Phasianidae, order Galliformes, which also includes other fowl-like birds, such as the grouse, ptarmigan, turkey, quail, peafowl, and pheasants.
The natural range of guinea fowl is sub-Saharan Africa, the Arabian Peninsula, and Madagascar. However, these birds have been introduced to some other places, and are commonly kept in aviculture. The usual habitats of guinea fowl are open forests, savannas, and grasslands.
The range of body lengths of guinea fowl is 17-29 in (43-75 cm). Their head and the upper part of their neck are devoid of feathers, but the skin is brightly colored in hues of blue, red, yellow, or grey. Some species have a bony structure known as a casque on the top of their head, while others have a wattle or other types of colored protuberances. Their bill is short but stout, the wings rather short and rounded, and the legs and feet are large and used for running and scratching in litter for their food of insects, seeds, roots, and rhizomes. The plumage is dark colored, but patterned with white spots and bars. The sexes are similar in shape and color.
Guinea fowl are terrestrial birds. They are powerful fliers, but only over a short distance. Guinea fowl generally prefer to run swiftly from danger rather than fly. Guinea fowl do not migrate.
The nests are crude scrapes on the ground, containing 2-20 eggs, which are brooded by the female. Both sexes care for the hatched young. Guinea fowl are highly gregarious birds, occurring in large flocks, especially during the non-breeding season, when they may also wander extensively. These flocks scatter readily when any bird perceives danger and utters an alarm call. The flock re-assembles later, as soon as one of the older, more-experienced males sounds an all-clear call.
The largest and most ornamentally plumaged species is the vulturine guinea fowl (Acryllium vulturinum) of central and east Africa. This is a relatively tall species, with long legs, an elongate neck, blue-skinned head, long downward hanging neck feathers known as hackles, a cobalt-blue colored breast, and a black body with white spots and stripes.
The helmeted or domestic guinea fowl (Numida meleagris) is originally from a wide range in sub-Saharan Africa, where it is commonly hunted as a game bird, as are other wild species of guinea fowl. However, the helmeted guinea fowl has also been domesticated. This species has long been kept in domestication in Africa and now more widely in tropical and south-temperate climates. Wild, naturalized populations also occur beyond the original range of this species, probably including the wild birds of Madagascar and smaller islands in the Indian Ocean, but also in Central America. The domestic guinea fowl is kept as a source of meat and eggs, although it is used for these purposes much less commonly than the domestic chicken (Gallus gallus, family Phasianidae). The domestic guinea fowl is also commonly kept as a pet.