CHICKEN English meaning

Genomic studies estimated that the chicken was domesticated 8,000 years ago in Southeast Asia and spread to China and India 2,000 to 3,000 years later. Fertile chicken eggs hatch at the end of the incubation period, about 21 days; the chick uses its egg tooth to break out of the shell. The concept of dominance, involving pecking, was described in female chickens by Thorleif Schjelderup-Ebbe in 1921 as the “pecking order”. Individual chickens dominate others, establishing a pecking order; dominant individuals take priority for access to food and nest sites. Chickens are primarily kept for their meat and eggs, though they are also kept as pets. In situations where one adult bird challenges another—which happens most often when a new bird is introduced into the flock—fights involving males risk injury and death more often than fights involving females.

Domestication

Mating typically involves a sequence in which the male approaches the female and performs a waltzing display. The dance triggers a response in the hen and when she responds to his call, the rooster may mount the hen and proceed with the mating. To initiate courting, some roosters may dance in a circle around or near a hen (a circle dance), often lowering the wing which is closest to the hen. Chickens give different warning calls to indicate that a predator is approaching from the air or on the ground. A male’s crowing is a loud and sometimes shrill call, serving as a territorial signal to other males, and in response to sudden disturbances within their surroundings. Chickens are capable of mobbing and killing a weak or inexperienced predator, such as a young fox.

• Chickens are gregarious, living in flocks, and incubate eggs and raise young communally.
• In groups of male chicks, however, fights for dominance may continue into adulthood.
• The market for chicken meat has grown dramatically since then, with worldwide exports reaching nearly 12.5 million metric tons (about 13.8 million tons) by the early 21st century.
• Whether it’s chicken curry, the perfect roast or an easy midweek meal, our collection of gorgeous chicken recipes has something for everyone.
• Only hens that could no longer produce enough eggs were killed and sold for meat.

Domestication and economic production

These chickens may have been introduced during pre-Columbian times to South America via Polynesian seafarers, but this is disputed. Skeletons of birds in the Gallus genus were used as grave goods at the site, confirming domestication. The chicks imprint on the hen and subsequently follow her continually. Eggs of chickens from the high-altitude region of Tibet have special physiological adaptations that result in a higher hatching rate in low oxygen environments.

Hens often try to lay in nests that already contain eggs and sometimes move eggs from neighbouring nests into their own. As with all birds, reproduction is controlled by a neuroendocrine system, the Gonadotropin-Releasing Hormone-I neurons in the hypothalamus. Sperm transfer occurs by cloacal contact between the male and female, in an action called the ‘cloacal kiss’. Chickens have been thought of primarily as providers of food, but their cognition, emotions, and sociality are comparable with other birds eaub.info and mammals. Chickens are gregarious, living in flocks, and incubate eggs and raise young communally. The body is round, the legs are unfeathered in most breeds, and the wings are short.

The domestic chicken has subsequently hybridised with grey junglefowl, Sri Lankan junglefowl and green junglefowl; a gene for yellow skin, for instance, was incorporated into domestic birds from the grey junglefowl (G. sonneratii). Chickens are descended primarily from the red junglefowl (Gallus gallus) and are scientifically classified as the same species. Wild junglefowl can fly, whereas domestic chickens and their flight muscles are too heavy to allow them to fly more than a short distance. Subsequent ovulations may occur within an hour after the previous egg was laid, allowing some hens to produce as many as 300 eggs per year.