A peacock, like a rooster, is always male. Just as a female chicken is a hen, a female peafowl is a peahen. Peafowl (spp. Pavo) are part of the pheasant family and have long been prized and even venerated. Hindus considered the Indian peafowl (P. cistasus) sacred, and it is still the national bird of India. The green peafowl (P. muticus) isn't as well-known in the west, but it can fill the air with the same earsplitting cawing as its cousin. Male peafowl are the ones with the impressive tails, more properly known as trains, and there's a good reason peahens don't have such showy coloration. They have to keep a low profile so they can raise their young without attracting predators. The young are known as peachicks.

A peacock's most distinguishing feature is its bronze and green train, which consists of 200 or more individual feathers. When on full display during courtship, iridescent bronze, blue and green "eyes of god" are visible, which is the reason for the adulation the bird has received through the ages. Females like a good train and are attracted to the male with the largest and most showy display. When not on display, the train trails behind the bird and accounts for 60 percent of its total length.

The train is distinct from the tail feathers, which it obscures. Some tail feathers are bronze, and some are speckled like those of a pheasant, to which the bird is related. Peahens lack a train, and the female Indian peafowl also lack the bright coloration of the tail feathers.

If the train isn't enough of a distinction, you can tell Indian peacocks from peahens by their coloration. Peacocks are covered with bright iridescent blue feathers, while the peahen feathers are mostly brown. The most vivid coloration you'll see on a peahen is a bluish ring around the neck, and except for this, the peahen has about the same coloration as one of her chicks. The brown feathers help camouflage her in the forest while she is nesting.

Green peafowl live in Southeast Asia in parts of China, Thailand, Myanmar and Vietnam. They are also native to Java and Indonesia and are sometimes called Java peafowl. The males have the showy train, but it's more difficult to tell the green peacocks from the peahens. Both have primarily green plumage with flecks of blue, bronze and reddish brown, and both have pheasant-like speckled plumage on their necks. The only difference between them is that the colors of the female bird are slightly less vivid than those of the male. Young green peafowl resemble the females.