Chicken
A flock thus uses only a few preferred locations, rather than having a different nest for every bird. Reproduction declines with age, thought to be due to a decline in GnRH-I-N. If the female is unreceptive, she runs off; otherwise, she crouches, and the male mounts, treading with both feet on her back.
- Females (mature hens and younger chickens, called pullets) are raised for meat and for their edible eggs.
- In 2006, scientists researching the ancestry of birds switched on a chicken recessive gene, talpid2, and found that the embryo jaws initiated formation of teeth, like those found in ancient bird fossils.
- Chickens are common and widespread domestic animals, with a total population of 23.7 billion as of 2018update.
- Only in the early 20th century, however, did chicken meat and eggs become mass-production commodities.
- Re-examination of bones from over 600 sites, and dating of those from 23 sites, identified the earliest probable chicken bones as from central Thailand, at Ban Non Wat, some 3,250 years ago.
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 and mammals.
Farming
Add chicken to one of your lists below, or create a new one. To add chicken to a word list please sign up or log in. Mature males have long been used for sport (i.e., cockfighting, now outlawed in many jurisdictions) as well as for breeding. Farmers have developed numerous breeds and varieties to fulfill commercial requirements. Descendants of those domestications have spread throughout the world in several waves for at least the last 2,000 years.
Domestication
More than 50 billion chickens are reared annually as a source of meat and eggs. An early study proposed that a single domestication event of the red junglefowl in present-day Thailand gave rise to the modern chicken. It is estimated that chickens share between 71 and 79% of their genome with red junglefowl. Domesticated chickens freely interbreed with populations of red junglefowl.
Leftover chicken broth with grains Mothership Sunday roast chicken Whether it’s chicken curry, the perfect roast or an easy midweek meal, our collection of gorgeous chicken recipes has something for everyone.
Domestication and economic production
Keeping chickens as pets became increasingly popular in the 2000s among urban and suburban residents. The first pictures of chickens in Europe are found on Corinthian pottery of the 7th century BC. Phoenicians spread chickens along the Mediterranean coasts as far as Iberia. 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.
There is some debate about what the chicken’s scientific name should be. Chickens have been featured in art in farmyard scenes such as Adriaen van Utrecht’s 1646 Turkeys and Chickens and Walter Osborne’s 1885 Feeding the Chickens. The pseudo-riddle «Why did the chicken cross the road?» dates to 1847, or earlier. This involves the sacrifice of a sacred rooster, often during a ritual cockfight, used as a form of communication https://chickenroadonline-bd.com/app/ with the gods.
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. Chicken can mean a chick, and this was historically the meaning of the word chicken, as in William Shakespeare’s play Macbeth, where Macduff laments the death of «all my pretty chickens and their dam». As of 2023, the global chicken population exceeds 26.5 billion, with more than 50 billion birds produced annually for consumption. It was first domesticated around 8,000 years ago and is one of the most common and widespread domesticated animals in the world.
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. Egg laying is stimulated by the long stretches of daylight that occur during the warmer months; however, artificial lights placed in chicken coops can trigger a hen’s egg laying response throughout the year.
Chickens belonging to the same age cohort and sex are often kept together in industrial production settings. A flock usually includes one dominant adult male, a few subdominant males, and two or more females that are carefully watched over by the dominant male. Chicks are born covered in down, but they mature quickly, becoming fully feathered after four to five weeks. Fertilized embryos develop quickly, and chicks hatch approximately 21 days later.
