The chicken (Gallus gallus domesticus) is a type of domesticated fowl, a subspecies of the red junglefowl (Gallus gallus). Chickens are one of the most common and widespread domestic animals, with a total population of 23.7 billion as of 2018, up from more than 19 billion in 2011. There are more chickens in the world than any other bird or domesticated fowl.