Pigeons are passerine birds in the family Columbidae, which is widely spread across the world, from the mountains of North America to the tropical rainforests of Africa. Pigeons and doves are actually in the same family, and these two terms are sometimes used interchangeably, with some people reserving “dove” for smaller birds in the family and “pigeon” for larger members of the family. Chances are very high that you have seen pigeons in your area, as these determined, hardy, and enterprising birds are able to set up shop almost anywhere. Like other passerines, pigeons have uniquely designed feet which allow them to perch, along with characteristically plump bodies, stubby beaks and legs, and small heads. Pigeons come in a wide variety of sizes and colors, from tiny doves which fit in the palm of the hand to the crowned pigeons of New Guinea, which can grow as large as turkeys. Some pigeons have drab brownish to gray plumage, while others come in an array of tropical colors like green, yellow, and red. All pigeons have adapted to eat a diet which consists primarily of fruit and seeds, and some are also enterprising scavengers who can find things to eat in the garbage. During mating season, pigeons build small, lightweight nests, laying two eggs which the parents incubate together. When the chicks hatch, the parents feed them on crop milk, a highly nutritious secretion of their crops. Crop milk is unique to members of the Columbidae family and the flamingos. One of the most famous pigeon species is probably the rock pigeon, also known as the common or city pigeon. Rock pigeons can be found in many urban areas around the world, and many regions treat them as pests, due to their messy droppings and loud lifestyle. Several pigeon varieties are also hunted as game, and in some areas roast pigeon is a delicacy, while some people like to raise racing pigeons; while the passenger pigeon is now extinct, racing pigeons share the passenger pigeon’s uncanny homing abilities. Many people recognize a pigeon instantly when it starts to move, as the birds walk with a very assertive, cocky strut, typically bobbing their heads as they move along. Pigeons are also famous for their vocalizations, which include throaty coos. While many of these birds have obviously been able to survive in human communities and adapt to a new way of life, other pigeon species were not so fortunate. During the 200 years between 1800 and 2000, at least 30 pigeon species went extinct, and several more are threatened or endangered.