The chicken ( Gallus gallus domesticus ) is a domesticated red junglefowl species that are originally from Southeast Asia . They have also partially hybridized with other wild species of junglefowls (the grey junglefowl , Ceylon junglefowl , and green junglefowl ). [1] Rooster and cock are terms for adult male birds, 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 . Humans keep
Chickens are one of the most common and widespread domestic animals, with a total population of 23.7 billion as of 2018 [update] , [2] up from more than 19 billion in 2011. There are more chickens in the world than any other bird . There are numerous cultural references to chickens —in myth, folklore and religion, and in language and literature.
Genetic studies have pointed to multiple maternal origin theories of within South Asia , Southeast Asia, and East Asia , [3] but the clade found in the Americas , Europe , the Middle East and Africa originated from the Indian subcontinent . From ancient India , the chicken spread to the Eastern Mediterranean. They appear in ancient Egypt in the mid-15th century BC, with the "bird that gives birth every day" having come from the land between Syria and Shinar , Babylonia , according to the annals of Thutmose