The Columbidae family, encompassing all doves and pigeons, is the sole group within the Columbiformes order. These birds have stout bodies, short necks, and short, slender bills, with variations that include fleshy ceres in some species. Dove and pigeon species, which are found globally with the most diversity in the Indomalayan and Australasian realms, feed mainly on seeds, fruits, and plants. The family consists of 344 species across 50 genera, including 13 extinct species. While smaller species are often termed "doves" and larger ones "pigeons" in English, this distinction isn't consistent and doesn't apply in other languages. Familiar pigeons, like the widespread domestic pigeon, are known for nesting in simple structures and laying mostly one or two white eggs. Both parent birds care for the young, known as squabs, which fledge between 25 and 32 days. Pigeons and doves are unique among birds for producing crop milk to feed their young. The names "pigeon" and "dove" have distinct etymologies and have varied in common use historically. The Columbiformes, closely related to sandgrouses and mesites, are believed to have diversified rapidly after the Cretaceous. While taxonomic classifications, including five subfamilies, are still under debate due to genetic analysis discrepancies, it's suggested that pigeons originated in the Australasian region. Doves and pigeons vary greatly in size and appearance, inhabit different environments worldwide, and while many benefit from human presence, others decline or become extinct, such as the dodo and the passenger pigeon, due to habitat loss, predation, and hunting. Conservation efforts include laws, habitat protection, and breeding programs. Historically, pigeons have been used in wars as message carriers and are still commemorated for their service. Domestic species like the rock dove have been bred for various purposes, including racing and ornamental traits. In culture and religion, doves often symbolize love, peace, and the Holy Spirit, and are featured in Christianity, Islam, and portrayed as sacred in ancient mythology. They are also hunted and raised for food in many cultures around the world.