Turkeys
Turkeys
Turkeys are relatively large, powerful, ground-feeding, North American birds with colorful, featherless heads, classified in the family Phasianidae. The original range of the common turkey (Meleagris gallopavo ) was from extreme southern Ontario to Mexico, but it now occupies a much smaller area. The second species in this group is the ocellated turkey (Agriocharis ocellata ), which occurs in southern Mexico, Guatemala, and Belize.
Turkeys are economically important birds. They are widely hunted in the wild, and are intensively reared on farms. The populations of wild turkeys are now greatly reduced, and much of their natural habitat has been destroyed, but many millions of these birds occur in captivity.
Biology of turkeys
Wild turkeys have a rather dark plumage, with some degree of iridescence. They have an featherless head, with brightly colored naked skin that is blue and red in the common turkey, and blue and orange in the ocellated turkey.
Turkeys are sexually dimorphic. Male turkeys (called “toms”) are relatively colorful and large, with a body length in the common turkey of up to 4 ft (1.2m), and a weight of up to 20 lb (9 kg). Turkeys have powerful legs, and male birds have a sharp spur on the back of the foot that can inflict serious wounds during combat with other males or possibly when fending off a predator.
The beak of male common turkeys is adorned by a wattle, which is a long, red, pendulous appendage that develops from tissues over the base of the upper mandible. During courtship displays the wattle is extended to a droopy length that is several times that of the beak. Male common turkeys also develop a fat-rich growth on their breast prior to the breeding season. This tissue helps to sustain the male turkeys during this intense period of the year, when their frequent, time-consuming, aggressive encounters with other males do not allow them to feed regularly. The constant preoccupation with displaying, mating, and fighting during the breeding period is hard on the toms, and they can be quite emaciated by the time this season has passed.
Wild turkeys mostly occur in forested and shrubby habitats, often with open glades. Turkeys forage on the ground in small groups, and spend the night roosting in trees. Turkeys are mostly herbivorous birds, eating a wide range of plant foods, although they also eat insects as they are encountered. Hard treefruits such as acorns and other nuts, known collectively as “mast,” are an important food that is gleaned from the forest floor. These hard seeds are ground with small stones and other grit in the powerful gizzard of turkeys, so that the nutritious matter can be digested and assimilated.
Turkeys are polygamous, meaning that a male bird will mate with as many females as possible. Male turkeys court females by elaborately spreading their fan like tail feathers, and by other visual displays, in which the wattle figures prominently. These displays are given while the tom struts proudly about, making loud “gobbling” noises. Male turkeys are extremely aggressive among themselves during the breeding season, and well-matched toms may fight to the death over access to females.
Female turkeys are alone responsible for building the ground nest, brooding the eight to 15 eggs, and raising the young. Turkey chicks are precocious, leaving the nest within a day of hatching, and following the female about and feeding themselves. Turkeys are gregarious after the breeding season, forming flocks that forage and roost together.
Turkeys and humans
Because of their large size and mild-tasting flesh, turkeys have long been hunted by humans as food and for sport. Until recently, wild common turkeys were badly overhunted in North America. This caused the wild populations of turkeys to decline over large areas, a resource collapse that was especially intense during the nineteenth century. Turkey populations were also badly damaged wherever there were extensive conversions of their forest habitat into agriculture, a change that has occurred over widespread regions.
Today, common turkeys do not occupy much of their former range, and they generally occur as isolated populations in fragmented habitats. However, turkeys have been re-introduced to many areas from which they were eliminated, and also to some regions where they were not native. These introductions, coupled with controls over hunting pressures, have allowed substantial increases in the populations of wild turkeys over much of their North American range.
It is not known when the common turkey was first domesticated, but this had already been accomplished by indigenous peoples of Mexico long before the Spanish conquest. The first turkeys seen by Europeans were apparently those domestic birds, some of which were taken to Europe for display and cultivation as a novel and tasty
food from the New World. The turkeys that are raised intensively today are derived from Mexican wild turkeys. Most domestic turkeys are white, although some varieties are black. Domestic turkeys have been artificially selected to have large amounts of meat, especially on the breast.
If the turkey came from the Americas, how did this bird receive its common name, which implies a Turkish origin? During the sixteenth century, when the domestic turkey was first introduced to England, the bird was thought to resemble the helmeted guinea-fowl (Numida meleagris). This species had been kept domestically since the fourth century BC, but had disappeared from Europe after the collapse of the Roman Empire. During the fifteenth and sixteenth centuries, Portuguese traders re-introduced domestic guineafowl to Europe, using birds that had been obtained in the region of Turkey. The common name in England of these re-introduced guineafowl was “turkey,” and this name was transferred to the superficially similar domestic turkey of the Americas when it was introduced somewhat later on.
Bill Freedman