This is the only living family to represent the order Columbiformes, as the second family (Raphidae, consisting fo the dodo and solitaires) became extinct during the 1700s due to human actions.
The family Columbidae is composed of over 300 species with a global distribution with the common exceptions: the Arctic, Antarctica, various deserts (Sahara & Arabian), and some islands. They are also quite adaptable to their environments–hello city pigeons and others. Once they were no longer being raised for food or communication purposes–they were all released into the wilds, and they have all survived and thrived in those particular locations and spread from there.
Approximately five to ten members of the family have become extinct since the 1600s. The most famous ‘case’ is the passenger pigeon that went from having numbers possibly in the billions to being extinct in the early 1900s. This was due to both habitat loss, but more pressing was the over-hunting of the bird as a source of meat and feathers.
Approximately another fifty to sixty species are listed as rare or endangered (mostly on islands), and the causes are a combination of introduced predators, loss of habitat, and over hunting.
There are several conservation techniques being used to help try to stabilize the populations: hunting regulations, breeding programs, setting up more ‘nature preserves’ to protect habitats, and relocating birds from one area to another.

Their diets are heavy on seeds and fruits–and they can even be divided into subfamilies based on their dietary preference: the mainly seed-eating species are in the subfamily Columbinae, while the mainly fruit-eating species are in the subfamily Leptotilinae. Though all have been known to supplement their diets with insects, snails, and worms.
Members of the family that can be spotted within the United States, Canada, and Mexico are:
Key west quail dove
White-tipped dove
Mourning dove
White-winged dove
Eurasian collared dove
Ringed turtle dove
Spotted dove
Inca dove
Common ground dove
Rock Dove–‘ancestor’ to the domestic pigeon, rock pigeon, and feral pigeons (all of which are a ‘single species’)
Red-billed pigeon
Band-tailed pigeon
White-crowned pigeon
Photography goals: to get a picture of all the species found within the US, plus get a picture of a species on the other continents. Though the domestic pigeon/rock pigeon/feral pigeon doesn’t count–as it is abundant in all large cities.
Reference: https://en.wikipedia.org/wiki/Columbidae