CHICKEN English meaning
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. Males (called cocks or roosters) and females (hens) are known for their fleshy combs, lobed wattles hanging below the bill, and high-arched tails. In the process of domestication, chickens were apparently kept initially for cockfighting, and only later used for food.
Reproduction and life-cycle
- The pseudo-riddle “Why did the chicken cross the road?” dates to 1847, or earlier.
- Despite the chicken’s close relationship with the red jungle fowl, there is evidence that the gray jungle fowl (G. sonneratii) of southern India and other jungle fowl species, also members of Gallus, may have contributed to the bird’s ancestry.
- Specialized breeds such as broilers and laying hens have been developed for meat and egg production, respectively.
- Middle Eastern chicken remains go back to a little earlier than 2000 BC in Syria.
- 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.
- As of 2023, the global chicken population exceeds 26.5 billion, with more than 50 billion birds produced annually for consumption.
Although many taxonomists and ornithologists consider it as a domesticated form of the wild red jungle fowl, some classify it as a subspecies of the red jungle fowl (i.e., G. gallus domesticus), whereas others, including the U.S. Chicken, (Gallus gallus), any of more than 60 breeds of medium-sized poultry that are primarily descended from the wild red jungle fowl (Gallus bd chicken road gallus, family Phasianidae, order Galliformes) of India. In the UK and Europe, laying hens are then slaughtered and used in processed foods, or sold as ‘soup hens’. Hens of some breeds can produce over 300 eggs per year; the highest authenticated rate of egg-laying is 371 eggs in 364 days.
Domestication
Analysis of the most popular commercial breed shows that the White Leghorn breed possesses a mosaic of divergent ancestries inherited from different subspecies of red junglefowl. Archaeological evidence appeared to support domestic chickens in Southeast Asia well before 6000 BC, China by 6000 BC and India by 2000 BC. Exactly when and where the chicken was domesticated was controversial. Inbreeding of White Leghorn chickens tends to cause inbreeding depression expressed as reduced egg number and delayed sexual maturity.
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. Some breeds have a mutation that causes extra feathering under the face, giving the appearance of a beard. Modern varieties however grow much faster; by day 35 a Ross 708 broiler may weigh 1.8 kg (4.0 lb) as against the 1.05 kg (2.3 lb) of a heritage chicken of the same age. Newly hatched chicks of both modern and heritage varieties weigh the same, about 37 g (1.3 oz).
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. 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”.
The hen sits on the nest, fluffing up or pecking defensively if disturbed. 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.
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.


