Family of birds
Columbidae is a bird family consisting of doves and pigeons. It is the only family in the order Columbiformes. These are stout-bodied birds with short necks and short slender bills that in some species feature fleshy ceres. They feed largely on plant matter, feeding on seeds (granivory), fruit (frugivory), and foliage (folivory). The family occurs worldwide, often in close proximity with humans, but the greatest diversity is in the Indomalayan and Australasian realms.
Columbidae contains 344 species divided into 50 genera. 59 species are listed as threatened, and 13 are extinct, including the dodo, an island bird, and the passenger pigeon, whose flocks were once counted in the billions.
In colloquial English, the smaller species tend to be called "doves", and the larger ones "pigeons", although the distinction is not consistent, and there is no scientific separation between them. Historically, the common names for these birds involve a great deal of variation. The bird most commonly referred to as "pigeon" is the domestic pigeon, or rock dove, which is common in many cities as the feral pigeon.
Doves and pigeons build relatively flimsy nests, often using sticks and other debris, which may be placed on branches of trees, on ledges, or on the ground, depending on species. They lay one or (usually) two white eggs at a time, and both parents care for the young. 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.
Unfledged baby doves and pigeons are called squabs and are generally able to fly by five weeks old. These fledglings, with their immature squeaking voices, are called squeakers once they are weaned, and leave the nest after 25–32 days.
Since ancient times, many species in Columbidae have developed intricate cultural and practical relations with humans. Doves were important symbols of the goddesses Innana, Asherah, and Aphrodite, and revered by the early Christian, Islamic and Jewish religions. Domestication of pigeons led to significant use of homing pigeons for communication, including war pigeons, such as the 32 pigeons who were awarded the Dickin Medal for "brave service" to their country, in World War II.
Etymology.
 is a French word that derives from the Latin , for a 'peeping' chick, while "dove" is an ultimately Germanic word, possibly referring to the bird's diving flight. The English dialectal word appears to derive from Latin . A group of doves has sometimes been called a "dule", taken from the French word ('mourning').
Origin and evolution.
Columbiformes is one of the most diverse non-passerine clades of neoavians, and its origins are in the Cretaceous and the result of a rapid diversification at the end of the K-Pg boundary. Whole genome analyses have found the columbiformes form a sister clade of a group conformed by the sandgrouses (Pterocliformes) and mesites (Mesitornithiformes).
Taxonomy and systematics.
The name 'Columbidae' for the family was first used by the English zoologist William Elford Leach in a guide to the contents of the British Museum published in 1819. Columbidae is the only living family in the order Columbiformes. The sandgrouse (Pteroclidae) were formerly placed here, but were moved to a separate order, Pterocliformes, based on anatomical differences (such as the inability to drink by "sucking" or "pumping").
The Columbidae were usually divided into five subfamilies, probably inaccurately. For example, the American ground and quail doves ("Geotrygon"), which are usually placed in the Columbinae, seem to be two distinct subfamilies. The order presented here follows Baptista etal. (1997), with some updates.
The arrangement of genera and naming of subfamilies is in some cases provisional because analyses of different DNA sequences yield results that differ, often radically, in the placement of certain (mainly Indo-Australian) genera. This ambiguity, probably caused by long branch attraction, seems to confirm the first pigeons evolved in the Australasian region, and that the "Treronidae" and allied forms (crowned and pheasant pigeons, for example) represent the earliest radiation of the group.
The family Columbidae also contains the former family Raphidae, consisting of the extinct Rodrigues solitaire and the dodo. These species are now known to be part of the Indo-Australian radiation that produced the three small subfamilies mentioned above, with the fruit doves and pigeons (including the Nicobar pigeon). Therefore, they are here included as a subfamily Raphinae, pending better material evidence of their exact relationships.
These taxonomic issues are exacerbated by columbids not being well represented in the fossil record, with no truly primitive forms having been found to date. The genus "Gerandia" has been described from Early Miocene deposits in France, but while it was long believed to be a pigeon, it is now considered a sandgrouse. Fragmentary remains of a probably "ptilinopine" Early Miocene pigeon were found in the Bannockburn Formation of New Zealand and described as "Rupephaps"; ""Columbina" prattae" from roughly contemporary deposits of Florida is nowadays tentatively separated in "Arenicolumba", but its distinction from "Columbina/Scardafella" and related genera needs to be more firmly established (e.g. by cladistic analysis). Apart from that, all other fossils belong to extant genera.
List of genera.
Fossil species of uncertain placement:
Description.
Size and appearance.
Pigeons and doves exhibit considerable variation in size, ranging in length from , and in weight from to above . The largest species is the crowned pigeon of New Guinea, which is nearly turkey-sized, at a weight of . The smallest is the common ground dove ("Columbina passerina") of the genus "Columbina", which is the same size as a house sparrow, weighing as little as . The dwarf fruit dove, which may measure as little as , has a marginally smaller total length than any other species from this family. One of the largest arboreal species, the Marquesan imperial pigeon, currently battles extinction.
Anatomy and physiology.
Overall, the anatomy of Columbidae is characterized by short legs, short bills with a fleshy cere, and small heads on large, compact bodies. Like some other birds, the Columbidae have no gall bladders. Some medieval naturalists concluded they have no bile (gall), which in the medieval theory of the four humours explained the allegedly sweet disposition of doves. In fact, however, they do have bile (as Aristotle had earlier realized), which is secreted directly into the gut.
The wings of most species are large, and have eleven primary feathers; pigeons have strong wing muscles (wing muscles comprise 31–44% of their body weight) and are among the strongest fliers of all birds.
In a series of experiments in 1975 by Dr.Mark B. Friedman, using doves, their characteristic head bobbing was shown to be due to their natural desire to keep their vision constant. It was shown yet again in a 1978 experiment by Dr.Barrie J. Frost, in which pigeons were placed on treadmills; it was observed that they did not bob their heads, as their surroundings were constant.
Feathers.
Columbidae have unique body feathers, with the shaft being generally broad, strong, and flattened, tapering to a fine point, abruptly. In general, the aftershaft is absent; however, small ones on some tail and wing feathers may be present. Body feathers have very dense, fluffy bases, are attached loosely into the skin, and drop out easily. Possibly serving as a predator avoidance mechanism, large numbers of feathers fall out in the attacker's mouth if the bird is snatched, facilitating the bird's escape. The plumage of the family is variable.
Granivorous species tend to have dull plumage, with a few exceptions, whereas the frugivorous species have brightly coloured plumage. The genera "Chalcophaps", "Ptilinopus" and "Alectroenas" include some of the most brightly coloured pigeons. Pigeons and doves may be sexually monochromatic or dichromatic. In addition to bright colours, some pigeon species may have crests or other ornamentation.
Flight.
Many Columbidae are excellent fliers due to the lift provided by their large wings, which results in low wing loading; They are highly maneuverable in flight and have a low aspect ratio due to the width of their wings, allowing for quick flight launches and ability to escape from predators, but at a high energy cost. A few species are long-distance migrants, with some populations of the European turtle dove migrating in excess of 5,000 km between northern Europe in summer and tropical Africa in winter, and the Oriental turtle dove nearly as far in eastern Asia between eastern Siberia and southern China.
Distribution and habitat.
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 semi-terrestrial. Various species also inhabit savanna, grassland, desert, temperate woodland and forest, mangrove forest, and even the barren sands and gravels of atolls.
Some species have large natural ranges. The eared dove ranges across the entirety of South America from Colombia to Tierra del Fuego, the Eurasian collared dove has a massive (if discontinuous) distribution from Britain across Europe, the Middle East, India, Pakistan and China, and the laughing dove across most of sub-Saharan Africa, as well as India, Pakistan, and the Middle East.
When including human-mediated introductions, the largest range of any species is that of the rock dove, also known as the common pigeon. This species had a large natural distribution from Britain and Ireland to northern Africa, across Europe, Arabia, Central Asia, India, the Himalayas and up into China and Mongolia. The range of the species increased dramatically upon domestication, as the species went feral in cities around the world. The common pigeon is currently resident across most of North America, and has established itself in cities and urban areas in South America, sub-Saharan Africa, Southeast Asia, Japan, Australia, and New Zealand. A 2020 study found that the east coast of the United States includes two pigeon genetic megacities, in New York and Boston, and observes that the birds do not mix together.
As well as the rock dove, several other species of pigeon have become established outside of their natural range after escaping captivity, and other species have increased their natural ranges due to habitat changes caused by human activity.
Other species of Columbidae have tiny, restricted distributions, usually seen on small islands, such as the whistling dove, which is endemic to the tiny Kadavu Island in Fiji, the Caroline ground dove, restricted to two islands, Truk and Pohnpei in the Caroline Islands, and the Grenada dove, which is only found on the island of Grenada in the Caribbean.
Some continental species also have tiny distributions, such as the black-banded fruit dove, which is restricted to a small area of the Arnhem Land of Australia, the Somali pigeon, found only in a tiny area of northern Somalia, and Moreno's ground dove, endemic to the area around Salta and Tucuman in northern Argentina.
Behaviour.
Feeding.
Seeds and fruit form the major component of the diets of pigeons and doves, and the family can be loosely divided between seed-eating, or granivorous, species, and fruit-and-mast-eating, or frugivorous, species, though many species use both resources.
The granivorous species typically feed on seed found on the ground, whereas the frugivorous species tend to feed in trees. The morphological adaptations used to distinguish between the two groups include granivores tending to having thick walls in their gizzards, intestines, and esophagi, with the frugivores evolved with thin walls, and the fruit-eating species have short intestines, as opposed to the seed eaters having longer intestines. 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, eat 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.
Urban feral pigeons, descendants of domestic rock doves ("Columbia Livia"), reside in urban environments, disturbing their natural feeding habits. They depend on human activities and interactions to obtain food, causing them to forage for spilled food or food provided by humans.
Status and conservation.
While many species of pigeons and doves have benefited from human activities and have increased their ranges, many