Genus Gallus Rank Species Phylum Chordata | Subfamily Phasianinae Scientific name Gallus gallus Higher classification Junglefowl Breeds Spanish gamecock | |
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The red junglefowl (Gallus gallus) is a tropical member of the family Phasianidae. It is the primary progenitor of the domestic chicken (though genetic evidence strongly suggests some past hybridisation with the grey junglefowl as well). The red junglefowl was first domesticated at least five thousand years ago in Asia. Since then it has spread around the world, and the domestic form is kept globally as a very productive food source of both meat and eggs.
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Range
The range of the wild form stretches from Tamil Nadu, India, eastwards across Indochina and southern China and into Malaysia, Singapore, Philippines and Indonesia. Junglefowl are established on several of the Hawaiian Islands, including Kauai, but these are feral descendants of domestic chickens. They can also be found on Christmas Island, Vanuatu, and the Mariana Islands.
Each of these various regions had its own subspecies of Gallus gallus, including:
Sexual dimorphism
The male's tail is composed of long, arching feathers that initially look black but shimmer with blue, purple and green in good light. The female's plumage is typical of this family of birds in being cryptic and adapted for camouflage. She alone looks after the eggs and chicks. She also has no fleshy wattles, and a very small comb on the head.
During their mating season, the male birds announce their presence with the well known "cock-a-doodle-doo" call or crowing. Male red junglefowl have a shorter crowing sound than domestic roosters; the call cuts off abruptly at the end. This serves both to attract potential mates and to make other male birds in the area aware of the risk of fighting a breeding competitor. A spur on the lower leg just behind and above the foot serves in such fighting. Their call structure is complex and they have distinctive alarm calls for aerial and ground predators to which others react appropriately.
Behaviour
Males make a food-related display called "tidbitting", performed upon finding food in the presence of a female. The display is composed of coaxing, cluck-like calls and eye-catching bobbing and twitching motions of the head and neck. During the performance, the male repeatedly picks up and drops the food item with his beak. The display usually ends when the hen takes the food item either from the ground or directly from the male’s beak. Breeding then occurs. Males that produce anti-predator alarm calls appear to be preferred by females.
They are omnivorous and feed on insects, seeds and fruits including those that are cultivated such as those of the oil palm.
Red junglefowl regularly bathe in dust to keep just the right balance in their plumage. The dust absorbs extra oil and subsequently falls off.
Flight in these birds is almost purely confined to reaching their roosting areas at sunset in trees or any other high and relatively safe places free from ground predators, and for escape from immediate danger through the day.
Domestication
In 2012, a study was published that examined mitochondrial DNA recovered from ancient bones from Europe, Thailand, the Pacific and Chile, and from Spanish colonial sites in Florida and the Dominican Republic, in directly dated samples originating in Europe at 1,000 B.P. and in the Pacific at 3,000 B.P. The study showed that chickens were most likely domesticated from wild red junglefowl, though some have suggested possible genetic contributions from other junglefowl species. Domestication occurred at least 7,400 years ago from a common ancestor flock in the bird's natural range, then proceeded in waves both east and west. The paper also states that the earliest undisputed domestic chicken remains are bones associated with a date of approximately 5,400 BC from the Chishan site, in the Hebei province of China. In the Ganges region of India, red junglefowl were being used by humans as early as 7,000 years ago. No domestic chickens older than 4,000 years have been identified in the Indus Valley, and the antiquity of chickens recovered from excavations at Mohenjodaro is still debated.
Hybridisation
The other three members of the genus—Sri Lanka junglefowl (Gallus lafayetii), grey junglefowl (Gallus sonneratii), and the green junglefowl (Gallus varius)—do not usually produce fertile hybrids with the red junglefowl, suggesting that it is the sole ancestor of the domestic chicken. However, recent research has revealed the absence of the yellow skin gene in the wild red junglefowl found in domestic birds, which suggests hybridisation with the grey junglefowl during the domestication of the species. A culturally significant hybrid between the red junglefowl and the green junglefowl in Indonesia is known as the bekisar.
Purebred red junglefowl are thought to be facing a serious threat of extinction because of hybridisation at the edge of forests where domesticated free ranging chickens are common.