The insect and seed-eating, ground-nesting birds of this family resemble partridges, but withfeatherless heads, though both members of the genus Guttera have a distinctive black crest, and the vulturine guineafowl has a downy brown patch on the nape. Most species of guineafowl have a dark grey or blackish plumage with dense white spots, but both members of the genus Agelastes lack the spots (as do some Wild variants of the helmeted guineafowl). While several species are relatively well known, the plumed guineafowl and the two members of the genus Agelastes remain relatively poorly known. These large birds measure from 40–71 cm (16–28 inches) in length, and weigh 700–1600 grams or 1.5 – 3.5 pounds.
The species for which the information is known are normally monogamous, mating for life or serially monogamous; however, occasional exceptions have been recorded for the helmeted and Kenyan crested guineafowl, which have been reported to be facultatively polygamous in captivity. All guineafowl are social, and typically live in small groups or large flocks. Though they are monogamous, species of the least-derived genera Guttera, Agelastes and Acrylliumtend toward social polyandry, a trait shared with other primitive galliformes like roul roul, and Congo peafowl.
Guineafowl travel behind herd animals and beneath monkey troops where they forage within manure and on items that have fallen to the understory from the canopy. Guineafowl play a pivotal role in the control of ticks, flies, locusts, scorpions and other invertebrates. They pluck maggots from carcasses and manure.
In the wild
Guineafowl species are found across sub-Saharan Africa, some almost in the entire range, others more localized, such as the plumed guineafowl in west-central Africa and the vulturine guineafowl in north-east Africa . They live in semi-open habitats such as savanna orsemideserts, while some, such as the black guineafowl, mainly inhabit forests. They perch high on treetops when reared in the extensive way. The helmeted guinea fowl has been introduced in East Africa, the West Indies, the United States, Britain and India, where it is raised as food or pets.