Pigeons kept in captivity can live to 15-20 years. A pigeon is about 13 inches (32 cm) in length from bill to tail and weighs a little less than a pound (0.35 kg). Males are slightly bigger than females.

Pigeons build their nests with small twigs. The male brings the nesting material to his mate, one piece at a time, and she builds the nest. Nests are usually well-hidden and hard to find. A pigeon nest usually is constructed on covered building ledges that resemble cliffs, a Rock Dove’s natural habitat. They also nest and roost on the support structures under bridges in cities and along highways.

There may be as many as 28 pigeon color types, called "morphs," but Project PigeonWatch groups them into just seven morphs. Pigeons also have colorful neck feathers. These iridescent green, yellow, and purple feathers are called "hackle." Adult males and females look alike, but a male’s hackle is more iridescent than a female’s.

Pigeons have many types of feathers including contour feathers, the stiff feathers that give the body its shape, and down, the fluffy insulating feathers. Many pigeon feathers are accompanied by one or two filoplume feathers, which look like hairs. These filoplumes may have sensory functions, such as, detecting touch and pressure changes.