Chicken

With more than 20 billion alive, the chicken is the most numerous bird on Earth, a domestic form of the red junglefowl of South and Southeast Asia. A junglefowl hen lays perhaps a dozen eggs a year, whereas hens of modern laying breeds produce around 300. Stout legs and blunt claws suit a bird that finds nearly all its food on the ground.

• Like all birds, chickens descend from theropod dinosaurs, the group that included Tyrannosaurus.
• Researchers have described more than 20 distinct chicken calls, including separate alarms for danger from the air and danger on the ground.
• A rooster that finds food often calls hens over while picking the item up and dropping it, a display known as tidbitting.
• In experiments, chicks only a few days old kept track of small numbers of objects hidden behind screens.
• The term pecking order comes from a Norwegian study of hens published in the 1920s.

Active from first light to dusk. As the light fades the flock goes to roost on perches or branches off the ground and sleeps through the night, and roosters begin crowing shortly before dawn.

Habitat: farmyard, village edge, garden, and managed grass run

Native range: Domestic worldwide

Omnivorous. Chickens eat grain, seeds, grass and other greens, insects, worms, snails and sometimes small lizards or mice. Having no teeth, they swallow grit, which lodges in the muscular gizzard and grinds the food.

Active from first light to dusk. As the light fades the flock goes to roost on perches or branches off the ground and sleeps through the night, and roosters begin crowing shortly before dawn.

Typically 5 to 10 years for a well-kept backyard bird, with occasional individuals reaching their teens. Commercial birds are slaughtered far younger.

A broody hen gathers a clutch of about 8 to 12 eggs, laid roughly one a day, then sits on them for 21 days. Chicks hatch covered in down and feed themselves within a day, staying close to the hen for several weeks.

Roosters have larger combs, wattles, spurs, and stronger display. They also grow long, pointed neck and saddle feathers and arched tail plumes, and they crow. Hens are smaller, with rounded feathers and a shorter tail.

Rarity: Relatively common · 4/100. Chicken remains fairly widespread where farmyard, village edge, garden, and managed grass run is still available.

• Keep distance and let the animal choose the space.
• Avoid blocking movement routes, nesting areas, or feeding behavior.
• Use optics, patience, and quiet observation instead of crowding for a closer view.