Guineafowl

(Numididae)

Class Aves

Order Galliformes

Suborder Phasiani

Family Numididae

Thumbnail description
Medium-sized, stocky, highly vocal birds with short, stout bills, and naked heads normally topped by casque or crest of feathers

Size
15.5–28.2 in (40–72 cm); 1.5–3.5 lb (0.7–1.6 kg)

Number of genera, species
4 genera; 6 species

Habitat
Forest, woodlands, and savanna

Conservation status
Vulnerable: 1 species

Distribution
Sub-Saharan Africa, introduced to extreme southern Arabia, Madagascar, and many tropical islands

Evolution and systematics

Guineafowl have sometimes been incorporated as a sub-family within the family Phasianidae, which includes pheasant-like birds such as turkeys, grouse, quails, and partridges. However, evidence from an examination of their internal anatomy, plumage, behavior, breeding biology, egg-white proteins, chromosomes, and DNA suggests that they be accorded family status. Their evolution, as with that of the Australasian megapodes (Megapodiidae) and the largely South American cracids (Cracidae), was almost certainly influenced by the break-up of Gondwana (the southern mega-continent comprising Australia, India, Africa and South America) over 100 million years ago. Guineafowl essentially bridge the evolutionary gap between the relatively advanced, pheasant-like birds (Superfamily Phasianoidea) and the anatomically primitive megapodes and cracids. There is no unequivocal fossil record of guineafowls before the Pleistocene.

Effects of climate change due to long-term fluctuations in rainfall and temperature and movement of landmasses have had a profound influence on guineafowl evolution. Expanding and contracting forests and open-country vegetation, and the development of the Rift Valley, have caused repeated fragmentation of the ranges of species tied to forests or open-country habitats. This process has promoted speciation and sub-speciation within the genera Agelastes, Guttera, and Numida.

As of 2001, the scientific community recognizes six species grouped within four genera. However, the crested guineafowl (Guttera pucherani) may be further sub-divided into a second species, G. edouardi.

Each species has a largely unfeathered head and neck; background body plumage is largely black, adorned (in most species) with tear-drop-sized white spots. The naked head and neck is thought to be an adaptation for cooling relatively warm arterial blood flowing upwards to the brain from the heart within a car-radiator-like nexus of micro-veins carrying relatively cool blood downwards. This "radiator" allows guineafowl to forage and socialize throughout the heat of the day.

Physical characteristics

Guineafowl are medium-sized, chicken-like birds with short, stout bills. They have strong legs, either without leg

spurs (genera Guttera and Numida), or with short, blunt, multiple spurs (genus Acryllium), or long, sharp, single spurs (genus Agelastes); these spurs grow directly out of the tarsometatarsus as in the junglefowl Gallus rather than the hypotarsus (as in most spurred galliforms). The tail is generally short and points downward, with 14 feathers (genus Agelastes) or 16 feathers (the rest of the genera). Guineafowl in the genera Guttera and Numida have cartilaginous wattles that hang from the base of the bill. The males, although larger and heavier on average, resemble the females in all species.

The two species of lowland forest guineafowl lack the characteristic white spotting on their plumage and have no adornments on their naked, red heads. The plumage of the black guineafowl (Agelastes niger) has a delicate, brownish wave design on the otherwise black plumage. The white-breasted guineafowl (Agelastes meleagrides), as its name implies, has white breast feathers. The rest of the body is black with fine, white, wavy bars. The body plumage of the remaining species of guineafowl is black with white spots.

The crested and plumed guineafowl (genus Guttera) each have a trachea, which forms a loop, embedded in a kind of pocket at the base of the wishbone. Plumed guineafowl (Guttera plumifera) have a brush-like tuft of straight feathers on the crown. Crested guineafowl (Guttera pucherani) have slightly to markedly curled feathers. There are five subspecies of crested guineafowl, but only two subspecies of plumed guineafowl, that vary mainly in the color of the facial skin on the head and the form of the feathered crest.

The head of the vulturine guineafowl (Acryllium vulturinum) is mostly featherless except for a chestnut-brown patch of short feathers on the sides and back of the head. This species has a hackle of spear-shaped feathers which have lengthwise stripes of black, white, and blue. The breast is blue, the edges of the wings are violet, and the rest of the plumage, except for the black ventral feathers, shows the usual spotted design. The central tail feathers are elongated and pointed. This guineafowl is slender and has longer legs than the helmeted guineafowl.

The helmeted guineafowl (Numida meleagris) has a bony casque or helmet on top of its head covered with horny cartilage. Each of the nine subspecies of helmeted guineafowl has a characteristic helmet shape. Each is also characterized by different coloring of the bare parts of the head, wattle, and neck feathers, as well as by the absence or presence of conspicuous bristles near the nostrils.

Distribution

With the exception of one (almost certainly extinct) sub-species of helmeted guineafowl that inhabited western Morocco, the original range of all guineafowl species is sub-Saharan Africa. Humans have introduced the helmeted guineafowl to southern Arabia, Madagascar, and as far afield as Cuba and other tropical islands, where they have acclimatized.

Black guineafowl occur in forests from Cameroon to the lower Congo and eastward into the Ituri territory. White-breasted guineafowl replace black guineafowl in the forests of Upper Guinea.

Plumed guineafowl inhabit forests in Cameroon, northern Congo, and the Central African Republic, extending southwards to Gabon and northern Angola. Crested guineafowl are distributed in less well-developed forests, from Guinea Bissau, eastward through Congo, the Democratic Republic of Congo, and as far as western Kenya, and southwards as far as Angola and northeastern South Africa.

Vulturine guineafowl inhabit the dry steppes of southern Ethiopia and southern Somalia as far as northwestern Tanzania.

Helmeted guineafowl occupy open-country areas virtually continuously from Senegal, eastwards to Somalia, and south to South Africa.

Habitat

Black guineafowl and white-breasted guineafowl inhabit primary, unspoiled, rainforests. Plumed guineafowl occur in primary rainforest and very mature secondary re-growth. Crested guineafowl prefer secondary forest, forest edge, and gallery forest. Helmeted guineafowl occupy virtually all open-country habitats in sub-Saharan Africa outside of deserts; they can thrive on cultivated land within which aggregations of more than 1,000 individuals (which are comprised of many flocks) may be encountered.

Behavior

All species of guineafowl live in sedentary groups when not breeding and in monogamous pairs when breeding.

Black guineafowl and white-breasted guineafowl live in groups of 15–20 and roost in trees at night. Their advertising calls are very different from other species of guineafowls. The calls consist of short, soft, low-pitched whistling sounds reminiscent of the cooing of doves.

The advertising calls of plumed and crested guineafowl are low-pitched "kuk-kuk-kuks" given in series and increasing in volume. Little is known about the behavior of plumed guineafowl.

Crested guineafowl occur in flocks averaging fewer than 20 birds. During early morning after descending from their nightly roosts, crested guineafowl flocks will move into forest glades to preen and socialize in the warmth of the morning

sun. In dim light before sunrise and after sunset, flocks will venture onto bush tracks and thus be vulnerable to collisions with motor vehicles, particularly because crested guineafowl will fly up from the track only to land in front of the vehicle due to the impenetrable vegetation on either side. Crested guineafowl will fly up into trees to feed on fruit rather than eat maize scattered on the ground. This species has also been observed, primarily in the late afternoon, foraging in association with vervet monkeys (Cercopithecus aethiops), feeding below on scraps of fruit and feces that fall to the forest floor. This relationship may also take advantage of a two-way alarm system: the monkeys warn of intruders from the trees above and the guineafowl scout out the forest floor. Although deeper than the call of the helmeted guineafowl, the crested guineafowl alarm call is also a staccato "chuk-chuk-chukchukerr." The lower pitch may be due, in part, to its windpipe being housed in the hollowed-out blade of its wishbone. Crested guineafowl are noisy, sometimes calling well into the night and during the quiet pre-dawn hours. Flock members keep in contact by emitting a low-pitched "chuk" call. Male crested guineafowl apparently do not have a hump-backed display as

in the helmeted guineafowl, but rather cock their tails like bantams when alarmed.

Vulturine guineafowl occur in flocks of 20–30 birds. Their advertising call is similar to that of the crested and plumed guineafowl, but is a much higher-pitched "keek-keek-keek," also given in series.

The helmeted guineafowl is by far the most social guineafowl species and may be seen in aggregations of hundreds of birds. At dawn, flock members fly down from their roost sites to a watering place. During early morning after drinking, they often seek patches of dry, light soil to dust bathe, presumably to rid themselves of feather parasites. During late morning and early afternoon, they stay in the shade. By late afternoon, they start looking for food, and at nightfall they return to their roosts, generally in tall trees.

Feeding ecology and diet

Black, white-breasted, plumed, and crested guineafowl feed on a range of plants and small invertebrates obtained by scratching in the leaf litter. In the case of white-breasted guineafowl, when one flock member finds a concentration of food, others immediately converge on it and try to crowd it away, pressing with their shoulders and pushing with their legs. However, birds competing for food do not use their bills aggressively during these encounters. Crested guineafowl may also feed in trees on berries and other fruits, and on bulbs from below the ground.

Vulturine guineafowl also feed on a range of plant and animal items and will sometimes perch in bushes to feed on fruits. Unlike all other guineafowl, this species appears to survive without readily-available drinking water.

Helmeted guineafowl are the most omnivorous of the guineafowl species, taking a broad range of plant and animal material (even small toads) from above and below the ground, switching their preferences to whatever appears to be abundant at the time, but focusing on insects and other arthropods during the breeding season.

Reproductive biology

Guineafowl appear to be monogamous breeders. Black guineafowl may be found breeding in any month of the year, but generally do so during drier months (December–February). The nest has not been described. The clutch size is unknown, and the eggs are pale reddish brown, sometimes with a violet or yellowish tinge. The downy keet (guineafowl chick) has dark-rufous back plumage with black markings.

White-breasted guineafowl may also breed during any month of the year, but breeding probably peaks at the end of the rainy season (November–January). The nest has not been described. Clutch size is about 12 eggs that are reddish buff with white pores. The back plumage of the downy keet is grayish brown with reddish brown highlights. The crown of the head and the mid-line of the neck are black.

Plumed guineafowl also appear not to have a fixed breeding season, but tend to nest during the rainy season(s). The nest is a simple scrape in the ground lined with leaves. Clutch size is 10 eggs that are pale buff with darkened pores. The downy keet has dark-buff back plumage with dark brownish black longitudinal stripes.

Crested guineafowl may also be found breeding during any month of the year in the equatorial parts of its range, but this species breeds during the rainy season in areas away from the equator. The nest is a simple scrape in the ground lined with leaves. Clutch size is normally four to five eggs, ranging up to seven eggs, that are dark buff to pinkish or white. The downy keet has dark-buff back plumage with dark brownish black longitudinal stripes. Chicks can flutter-fly at 12 days and fledge in downy plumage at about 30 days.

Vulturine guineafowl breed primarily during June and December–January, after the rainy seasons. The nest is a simple scrape in the ground, generally in thick grassy areas. Clutch size is 7–10 eggs, ranging up to 15 eggs, that are creamy white to pale brown. The incubation period is 22–25 days. The downy keet has yellowish buff back plumage with dark brownish black mottling.

For helmeted guineafowl, the breeding season is strongly tied to the timing and amount of rainfall. In west Africa, they breed during May–July. In southern Africa, the most intense

breeding activity is during summer (October–March) in the predominantly summer-rainfall regions of eastern and southern South Africa, and during late summer and early autumn ( January–March) in the north (in Botswana and Namibia). Breeding activity is, however, determined largely by the timing of regular heavy rainfall—in the winter-rainfall regions (the Western Cape and the western half of the Eastern Cape), peak breeding is between September and December, to take advantage of food fostered by winter rains. The nest is a simple scrape in the ground lined with grass, protected by a bush or tall grass. Clutch size is 12–23 eggs that are extremely hard-shelled, brown or yellowish brown in color, and pointed at one end. The downy keet has dark buff back plumage with blackish brown longitudinal stripes. Chicks can flutter-fly at 14 days and fledge in downy plumage at about 30 days.

Conservation status

The white-breasted guineafowl is Vulnerable, according to the IUCN. It is extremely sensitive to habitat destruction and illegal hunting by humans. On a global scale, none of the other species of guineafowl appears to be threatened.

Significance to humans

Members of the subspecies of helmeted guineafowl from the vicinity of what was then known as the Gulf of Guinea (hence the family name) in western Africa were domesticated in Europe and selected artificially for rapid growth to a heavier body mass (i.e., for meat production). Additional effects of this selection have been a change in color of the body plumage from black to white (or partly white) and of the legs and toes from black to yellow-orange.

Helmeted guineafowl are also highly prized, but grossly undervalued, objects of wingshooting (gamebird hunting).

Species accounts

List of Species

Helmeted guineafowl

Numida meleagris

TAXONOMY

Phasianus meleagris Linnaeus, 1758, Africa = Nubia, Upper Nile. Nine subspecies.

OTHER COMMON NAMES

French: Pintade de Numidie; German: Helmperlhuhn; Spanish: Pintade Común.

PHYSICAL CHARACTERISTICS

20–25 in (50–63 cm),2.5–3.5 lb (1.15–1.6 kg) male and female. Plumage mainly blackish gray with white spots and lines. Widespread variation among the subspecies in the head adornments (filoplumes, cere, wattles, and casque).

DISTRIBUTION

N. m. sabyi (probably extinct): northwestern Morocco; N. m. galeata: sub-Saharan, to northern Senegal and into northern Angola; N. m. meleagris: sub-Saharan, north of equator to Sudan and western Ethiopia; N. m. somaliensis: eastern Ethiopia to Eritrea and Somalia; N. m. reichenowi: Kenya and central Tanzania; N. m. mitrata: western and eastern Tanzania to northern Mozambique; N. m. marungensis: southern Congo to Angola and western Zambia; N. m. damarensis: extreme southwestern Angola to Namibia and western Botswana; N. m. coronata: Zimbabwe, southern Mozambique and South Africa.

HABITAT

Open savannas, woodland and dry thorn-scrub.

BEHAVIOR

Highly social and vocal; sexually dimorphic. Usually in flocks of up to 35 individuals but may form aggregations of more than 1,000 birds in feeding areas.

The timing of roosting is strongly correlated to the time of sunset, with later roosting on longer days. In May 1970 on the island of Nantucket, Massachusetts, a flock of domesticated

helmeted guineafowl took to their roost during a total eclipse of the sun at midday.

FEEDING ECOLOGY AND DIET

Active forager, mainly on the ground. Forages opportunistically on what is abundant. Omnivorous.

REPRODUCTIVE BIOLOGY

Apparently monogamous. 12–23 eggs with 24–27 day incubation time. Both parents feed and care for newly hatched chicks, known as downy keets. Breeding period varies depending on subspecies and rainfall patterns.

CONSERVATION STATUS

Widespread and common at the continental scale, but recent documentation indicates significant declines in parts of the range, probably due to habitat destruction.

SIGNIFICANCE TO HUMANS

Probably Africa's (and certainly southern Africa's) most popular terrestrial gamebird. Domesticated in Europe and introduced elsewhere.