|Image from Birding Information|
There are actually several subspecies of the rock pigeon. These include the wild birds, domestic pigeons, and the feral, city dwelling populations. There is evidence that pigeons were domesticated between 5,000 and 10,000 years ago. Humans have used pigeons for many purposes over the years. They have been used as a food supply, as animals for experimentation, for sport, and as message carriers. During World Wars I and II, pigeons were used extensively as message carriers, and participated in battles such as Ypres, Verdun, and the Normandy Invasion. Several pigeons were award the Dicken Medal, the U.K.'s highest animal award. Charles Darwin wrote about Rock Pigeons at length, and even kept a few of them for his studies.
Pigeons are herbivores, and only rarely will they consume insects. Their diet consists of fruit, seeds, and whatever things they can scavenge off of the sidewalks. In the wild they nest in high, cliff areas, which made the transition to urban dwelling perhaps a bit easier. Both parents care for their young, feeding them a substance called "pigeon milk" that is produced in their crop. Pigeons come in a wide variety of colors, though grey is the most common. Their feet are nearly always pink.