The terms "pigeon" and "dove" are informal and are not used to imply taxonomic divisions within the group. The terms are often used interchangeably, although there is a tendency for the term "pigeon" to be used when referring to larger species and "dove" to be used when referring to smaller species.
Pigeons and doves are small to medium size birds. They have short legs, a portly body, short neck and small head. Their plumage usually consists of various tones of grey and tan although some species have iridescent swatches of feathers adorning their neck as well as bars and spots on their wings and tail. Pigeons and doves have short bills which are hard at the tip but softer at the base where the bill meets with a naked cere (a waxy structure that covers the portion of the bill closest to the face).
The diet of pigeons and doves consists primarily of seeds and fruit. Most species forage on the ground or by picking food from bushes and trees. Some species also eat insects.
Pigeons and doves are most successful in open habitats such as grasslands, fields, deserts, agricultural lands and urban areas. They also inhabit temperate and tropical woodlands and mangrove forests to a lesser extent. Some species have extensive natural ranges while others are more restricted in distribution. The species with the widest range of all pigeons and doves is the rock dove (Columba livia), the city-dwelling species most commonly referred to as simply "a pigeon.
As a group, pigeons and doves are cosmopolitan birds, inhabiting a near worldwide range that excludes only the driest and coldest of habitats such as the Sahara Desert, the Arctic and Antarctica. They are present on may oceanic islands.
Pigeons and doves are monogomous and pairs often remain together for more than one breeding season. Pairs often produce multiple broods each year and share in the incubation and rearing of the young.
Pigeons and doves build platform nests constructed out of twigs and occasionally lined with pine needles or other soft materials such as root fibers. They build their nests on the ground, in trees, bushes or cacti, trees or on ledges. Some species build their nest atop the vacant nests of other birds.
Pigeons and doves usually lay one or two eggs per clutch (sometimes up to four). The male and female switch-off sitting on the eggs. The incubation period lasts between 12 and 14 days (although the incubation period varies from species to species). After hatching, adults feed their chicks crop milk, a liquid produced by the lining of the crop and which provides fats and proteins that nourish the young. When young reach about 10 to 15 days old, the adults feed them regurgitated seeds and fruit. Young fledge at about 11 to 16 days of age.
Pigeons and doves are divided into two groups, the Raphidae (an extinct group of flightless birds that included the dodo) and the Columbidae (the group that includes all living pigeons and doves).
Pigeons and doves are a coherent group of birds that are quite convincingly closely related, yet scientists are uncertain which bird group represents their closest living relatives. The fossil record for the group is sparse, a matter that further complicates a clear understanding of their evolutionary relationships.
There are two well-known members of the group that are now extinct, the dodo and the passenger pigeon.