Chickens are a popular source of animal protein around the world. The male chicken is called a rooster. The rooster (Gallus gallus domesticus) descended primarily from the Red Junglefowl (Gallus gallus). Today, these domesticated subspecies are reared primarily as a source of food for their meat and eggs. Interestingly, when humans first domesticated chickens, they were not intended for their meat and eggs but for the sport of cockfighting.