Chicken

== Description ==
The chicken (Gallus domesticus ) is a domesticated junglefowl species, with attributes of wild species such as the grey and the Ceylon junglefowl that are originally from Southeastern Asia. Rooster or cock is a term for an adult male bird, and a younger male may be called a cockerel. A male that has been castrated is a capon. An adult female bird is called a hen and a sexually immature female is called a pullet.
== Appearance ==
Populations of chickens from high altitude regions like Tibet have special physiological adaptations that result in a higher hatching rate in low oxygen environments. When eggs are placed in a hypoxic environment, chicken embryos from these populations express much more hemoglobin than embryos from other chicken populations. This hemoglobin also has a greater affinity for oxygen, allowing hemoglobin to bind to oxygen more readily.
== Lifestyle ==
Domestic chickens are not capable of long-distance flight, although lighter chickens are generally capable of flying for short distances, such as over fences or into trees (where they would naturally roost). Chickens may occasionally fly briefly to explore their surroundings, but generally do so only to flee perceived danger. Chickens are gregarious birds and live together in flocks. They have a communal approach to the incubation of eggs and raising of young. Individual chickens in a flock will dominate others, establishing a 'pecking order', with dominant individuals having priority for food access and nesting locations. Removing hens or roosters from a flock causes a temporary disruption to this social order until a new pecking order is established. Adding hens, especially younger birds, to an existing flock can lead to fighting and injury. Chickens may occasionally gang up on a weak or inexperienced predator. At least one credible report exists of a young fox killed by hens. A group of hens have been recorded in attacking a hawk that had entered their coop.
== Reproduction ==
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. 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.
== Domestication ==
Keeping chickens as pets became increasingly popular in the 2000s among urban and suburban residents. Many people obtain chickens for their egg production but often name them and treat them as any other pet like cats or dogs. Chickens provide companionship and have individual personalities. While many do not cuddle much, they will eat from one's hand, jump onto one's lap, respond to and follow their handlers, as well as show affection.
== Main References ==
https://animalia.bio/chicken
Category:Animalia
Category:Animals
Category:Chordata
Category:Vertebrata
Category:Vertebrates
Category:Aves
Category:Birds
Category:Galliformes
Category:Phasianidae
Category:Gallus
Category:Diurnal Animals
Category:Omnivores
Category:Terrestrial Animals
Category:Arboreal Animals
Category:Domesticated Animals
Category:Cosmopolitians
Category:Asian Animals
Category:African Animals
Category:Oceanian Animals
Category:European Animals
Category:North American Animals
Category:South American Animals
Category:Not Evaluated Animals