Annie Potts - Chicken

The discovery in 1861 of the fossilized remains of the archaeopteryx first led palaeontologists to speculate that birds evolved from dinosaurs. The archaeopteryx, thought to have lived in Jurassic Bavaria around 147 million years ago, possessed rudimentary feathers and wings. We now know that other dinosaurs also grew feathers; some, like modern-day birds, were warm-blooded and hollow-boned. Advances in genetic research suggest that the ancestry of birds is much more closely and complexly connected to the carnivorous theropods than any other dinosaurs.

The direct ancestor of the chicken (the pre-chicken) evolved somewhat later, probably around 50 million years ago. Fossils of Gallus are relatively scarce and have mainly been found in southern Europe. Fossil discoveries here imply that the ancestors of todays jungle fowl dispersed into warmer territories during periods of glaciation; when temperatures increased and glaciers

The wild jungle fowl, from which the domestic chicken descends, belongs to the order Galliformes, suborder Galli, family Phasianidae (which also includes pheasants, partridges, peafowl, quail, francolins and monals). Subfamilies of Phasianidae are distinguished according to the manner of tail moulting. Chickens belong to the second subfamily (Phasianinae), in which moulting is centripetal (the pattern of tail-feather loss occurs from the outside to the centre).

Phasianids are generally territorial ground-dwelling non-migratory birds. They tend to have shortish wings, solid legs and short, strong beaks. Males are larger than females, possess spurs, and have brightly coloured plumage and facial ornaments such as wattles and combs. Hens are often described asdrab in comparison, but their less eye-catching plumage camouflages them when they are nesting on the ground to incubate eggs. These birds are reasonably powerful short-range flyers, which allows speedier escape from predators and safer roosting in trees at dusk.

The four recognized species of modern wild jungle fowl include the red (Gallus gallus), the Sri Lanka (Gallusg. lafayetii), the green (Gallusg. varius) and the grey (Gallusg. sonneratii). Red, grey and Sri Lanka jungle fowl prefer tropical or subtropical forest habitats, while the green tends to live near the seashore or by scrubland bordering cultivated land. The grey inhabits western and southern India, while the Sri Lanka lives naturally only where its name suggests. The unusual green jungle fowl, found in Java and islands eastward, where it occupies different habitats from the red, is thought to be the most primitive of the four, boasting sixteen tail feathers and short hackle feathers, whereas the other species possess fourteen tail feathers and long pointed hackle feathers.

Gallus gallus varius, the green jungle fowl; a hand-coloured lithograph from Daniel Giraud Elliot, A Monograph of the Phasianidae (Family of Pheasants) (1872).

There are no subspecies of grey, green or Sri Lanka jungle fowl, but several subspecies of red jungle fowl exist: the Cochin-Chinese red (G. g. gallus), located in Thailand, Laos, Cambodia and south Vietnam; the Indian red (G. g. murghi) of north and north-east India, Nepal and Bangladesh; the Burmese (G. g. spadiceus), found in south-west China, Myanmar, Malaysia, north Sumatra and Thailand (except in the east); the Javan red (G. g. bankiva), located in south Sumatra, Bali and Java; and the Tonkinese red (G. g. jabouillei) of south-west China and north Vietnam. These five distinct subspecies of red jungle fowl are unable to interbreed with each other but they are capable of successfully mating with domestic chickens.

Wild and domesticated red jungle fowl were introduced to Kenya, the Philippines and other Pacific islands in Micronesia, Melanesia and Polynesia (forced introductions to Australia, New Zealand and North America were not successful). Red jungle fowl were also brought to Hawaii around 700 years ago by colonizing Polynesians; today families of feral chickens can be seen roaming the streets, forests and even the beaches of Kauai.