Pigeons are stout-bodied birds with short necks, and short, slender bills with fleshy ceres. They feed on seeds, fruits, and plants. This family occurs worldwide, but the greatest variety is in the Indomalaya and Australasia ecozones. In general, the terms "dove" and "pigeon" are used somewhat interchangeably. Pigeon is a French word that derives from the Latin pipio, for a "peeping" chick, while dove is a Germanic word that refers to the bird's diving flight. In ornithological practice, "dove" tends to be used for smaller Species and "pigeon" for larger ones, but this is in no way consistently applied, and historically, the common names for these birds involve a great deal of variation between the terms. The species most commonly referred to as "pigeon" is the feral rock pigeon, common in many cities.
Doves and pigeons build relatively flimsy nests – often using sticks and other debris – which may be placed in trees, on ledges, or on the ground, depending on species. They lay one or two eggs at a time, and both parents care for the young, which leave the nest after seven to 28 days. Unlike most birds, both sexes of doves and pigeons produce "crop milk" to feed to their young, secreted by a sloughing of fluid-filled cells from the lining of the crop. Young doves and pigeons are called "squabs".
Pigeons and doves exhibit considerable variations in size. The largest species is the crowned pigeon of New Guinea, which is nearly turkey-sized, at a weight of 2–4 kg (4.4–8.8 lb) The smallest is the New World ground-dove of the genus Columbina, which is the same size as a house sparrow and weighs as little as 22 g. With a total length of more than 50 cm (19 in) and weight of almost 1 kg (2 lb), the largest arboreal species is the Marquesan imperial pigeon, while the dwarf fruit dove, which may measure as little as 13 cm (5.1 in), has a marginally smaller total length than any other species from this family.
Pigeons and doves are distributed everywhere on Earth, except for the driest areas of the Sahara Desert, Antarctica and its surrounding islands, and the high Arctic. They have colonised most of the world's oceanic islands, reaching eastern Polynesia and the Chatham Islands in the Pacific, Mauritius, the Seychelles and Réunion in the Indian Ocean, and the Azores in the Atlantic Ocean.
The family has adapted to most of the habitats available on the planet. These species may be arboreal, terrestrial, or semiterrestrial. Various species also inhabit savannas, grasslands, deserts, temperate woodlands and forests, mangrove forests, and even the barren sands and gravels of atolls.
Seeds and fruit form the major component of the diets of pigeons and doves. In fact, the family can be divided into the seed-eating or granivorous species (subfamily Columbinae) and the fruit- and mast-eating or frugivorous species (the other four subfamilies). The granivorous species typically feed on seed found on the ground, whereas the frugivorous species tend to feed in trees. There are morphological adaptations that can be used to distinguish between the two groups; granivores tend to have thick walls in their gizzards, whereas the frugivores tend to have thin walls. In addition, fruit-eating species have short intestines, whereas those that eat seeds have longer ones. Frugivores are capable of clinging to branches and even hang upside down to reach fruit.
In addition to fruit and seeds, a number of other food items are taken by many species. Some, particularly the ground-doves and quail-doves, take a large number of prey items such as insects and worms. One species, the atoll fruit dove is specialised in taking insect and reptile prey. Snails, moths and other insects are taken by white-crowned pigeons, orange fruit doves and ruddy ground doves.
While many species of pigeons and doves have benefited from human activities and have increased their ranges, many other species have declined in numbers and some have become threatened or even succumbed to extinction. Among the 10 species to have become extinct since 1600 (the conventional date for estimating modern extinctions) are two of the most famous extinct species, the dodo and the passenger pigeon.
The passenger pigeon was exceptional for a number of reasons. It is the only pigeon species to have gone extinct in modern times that was not an island species. It was once the most numerous species of bird on Earth. Its former numbers are difficult to estimate, but one ornithologist, Alexander Wilson, estimated one flock he observed contained over two billion birds. The decline of the species was abrupt; in 1871, a breeding colony was estimated to contain over a hundred million birds, yet the last individual in the species was dead by 1914. Although habitat loss was a contributing factor, the species is thought to have been massively overhunted, being used as food for slaves and, later, the poor, in the United States throughout the 19th century.
The pigeon has contributed to both World War I and II, notably by the Australian, French, German, American, and UK forces. Thirty-two pigeons have been decorated with the Dickin Medal for war contributions, including Commando, G.I. Joe, Paddy, and William of Orange.
Cher Ami, a homing pigeon in World War I, was awarded the Croix de Guerre Medal with a palm Oak Leaf Cluster for her service in Verdun and for delivering the message that saved the Lost Battalion of the 77th Infantry Division in the Battle of the Argonne, October 1918. When Cher Ami died, she was mounted and is part of the permanent exhibit at the National Museum of American History of the Smithsonian Institution.
A grand ceremony was held in Buckingham Palace to commemorate a platoon of pigeons that braved the battlefields of Normandy to deliver vital plans to Allied forces on the fringes of Germany. Three of the actual birds that received the medals are on show in the London Military Museum so that well-wishers can pay their respects.
Several species of pigeons and doves are used as food, and probably any could be; the powerful breast muscles characteristic of the family make excellent meat. Domesticated or hunted pigeon have been used as the source of food since Ancient Middle East, Ancient Rome and Medieval Europe. It is familiar meat within Jewish, Arab, Assamese cuisine and French cuisines. According to the Tanakh, doves are kosher, and they are the only birds that may be used for a korban. Other kosher birds may be eaten, but not brought as a korban. It is also known in Asian cuisines, such as Chinese and Indonesian.
In Europe, the wood pigeon is commonly shot as a game bird, while rock pigeons were originally domesticated as a food species, and many breeds were developed for their meat-bearing qualities. The extinction of the passenger pigeon in North America was at least partly due to shooting for use as food. Mrs Beeton's Book of Household Management contains recipes for roast pigeon and pigeon pie, a popular, inexpensive food in Victorian industrial Britain.