|peace dove||dove branch||pigeon fly|
There are more than 300 species in the family. They usually make nests of sticks, and their two white eggs are incubated by both the male and the female parent. Doves feed on seeds, fruit and plants.
Unlike most other birds, the doves and pigeons produce a type of milk. It is produced in their crop, and called crop milk. Both sexes have this highly nutritious milk to feed their young.
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 or terrestrial or partly terrestrial. Species live in savannas, grasslands, deserts, temperate woodlands and forests, mangrove forests, and even the barren sands and gravels of atolls. Some species have large natural ranges.
The largest range of any species is that of the rock dove. This species lives in Britain and Ireland, northern Africa, across Europe, Arabia, Central Asia, India, the Himalayas and up into China and Mongolia. The range of the species increased dramatically after is was domesticated, because the species went feral in cities around the world. It lives in cities across most of North America, South America, sub-Saharan Africa, Southeast Asia, Japan, Australia and New Zealand.
The species is not the only pigeon to have increased its range due to the actions of man; several other species have become established outside of their natural range after escaping captivity. Other species have also increased their natural ranges due to habitat changes by humans.
The dodo and the Rodrigues solitaire are two famous flightless birds on the Macarene Islands in the Indian Ocean, east of Madagascar. They are extinct, but were alive before sailors found the islands. They had no fear of humans, whom they had never seen. The sailors hunted them, and killed them for food. Both species are now extinct. Animals introduced by man may also have hunted them. Their anatomy (osteology) and DNA sequence analyses show they were are in the Columbidae.
In the Ancient Near East and Mediterranean, doves were used as symbols for the Canaanite mother goddess Asherah, the Phoenician goddess Tanit, and the Roman goddesses Venus and Fortunata.
The Christian symbol of a dove with an olive branch in its beak represents peace and comes from Genesis 8:6 - 12, also John 1:32–34. The Christian stories came after very similar myths from earlier cultures.The Chaldean myth the Epic of Gilgamesh, Utnapishtim releases a dove and raven to find land; however, the dove merely circles and returns. Only then does Utnapishtim send forth the raven, which does not return, and Utnapishtim concludes the raven has found land.
Birds (Aves) are a group of endothermic vertebrates, characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a lightweight but strong skeleton. Birds live worldwide and range in size from the 5 cm (2 in) bee hummingbird to the 2.75 m (9 ft) ostrich. They rank as the class of tetrapods with the most living species, at approximately ten thousand, with more than half of these being passerines, sometimes known as perching birds or, less accurately, as songbirds.
The fossil record indicates that birds are the last surviving group of dinosaurs, having evolved from feathered ancestors within the theropod group of saurischian dinosaurs. True birds first appeared during the Cretaceous period, around 100 million years ago. DNA-based evidence finds that birds diversified dramatically around the time of the Cretaceous–Paleogene extinction event that killed off all other dinosaurs. Birds, especially those in the southern continents, survived this event and then migrated to other parts of the world while diversifying during periods of global cooling. Primitive bird-like dinosaurs that lie outside class Aves proper, in the broader group Avialae, have been found dating back to the mid-Jurassic period. Many of these early ,,stem-birds", such as Archaeopteryx, were not yet capable of fully powered flight, and many retained primitive characteristics like toothy jaws in place of beaks, and long bony tails.
Birds have wings which are more or less developed depending on the species; the only known groups without wings are the extinct moas and elephant birds. Wings, which evolved from forelimbs, give most birds the ability to fly, although further speciation has led to some flightless birds, including ratites, penguins, and diverse endemic island species of birds. The digestive and respiratory systems of birds are also uniquely adapted for flight. Some bird species of aquatic environments, particularly the aforementioned flightless penguins, and also members of the duck family, have also evolved for swimming. Birds, specifically Darwin's finches, played an important part in the inception of Darwin's theory of evolution by natural selection.
Some birds, especially corvids and parrots, are among the most intelligent animals; several bird species make and use tools, and many social species pass on knowledge across generations, which is considered a form of culture. Many species annually migrate great distances. Birds are social, communicating with visual signals, calls, and bird songs, and participating in such social behaviours as cooperative breeding and hunting, flocking, and mobbing of predators. The vast majority of bird species are socially monogamous, usually for one breeding season at a time, sometimes for years, but rarely for life. Other species have polygynous (,,many females") or, rarely, polyandrous (,,many males") breeding systems. Birds produce offspring by laying eggs which are fertilized through sexual reproduction. They are usually laid in a nest and incubated by the parents. Most birds have an extended period of parental care after hatching. Some birds, such as hens, lay eggs even when not fertilized, though unfertilized eggs do not produce offspring.
Many species of birds are economically important. Domesticated and undomesticated birds (poultry and game) are important sources of eggs, meat, and feathers. Songbirds, parrots, and other species are popular as pets. Guano (bird excrement) is harvested for use as a fertilizer. Birds prominently figure throughout human culture. About 120–130 species have become extinct due to human activity since the 17th century, and hundreds more before then. Human activity threatens about 1,200 bird species with extinction, though efforts are underway to protect them. Recreational birdwatching is an important part of the ecotourism industry.
The first classification of birds was developed by Francis Willughby and John Ray in their 1676 volume Ornithologiae. Carl Linnaeus modified that work in 1758 to devise the taxonomic classification system currently in use. Birds are categorised as the biological class Aves in Linnaean taxonomy. Phylogenetic taxonomy places Aves in the dinosaur clade Theropoda.