The rock dove, rock pigeon, or common pigeon ( also ; Columba livia) is a member of the bird family Columbidae (doves and pigeons).: 624  In common usage, it is often simply referred to as the "pigeon". The domestic pigeon (Columba livia domestica, which includes about 1,000 different breeds) descended from this species. Escaped domestic pigeons have increased the populations of feral pigeons around the world.Wild rock doves are pale grey with two black bars on each wing, whereas domestic and feral pigeons vary in colour and pattern. Few differences are seen between males and females. The species is generally monogamous, with two squabs (young) per brood. Both parents care for the young for a time.Habitats include various open and semi-open environments. Cliffs and rock ledges are used for roosting and breeding in the wild. Originally found wild in Europe, North Africa, and western Asia, pigeons have become established in cities around the world. The species is abundant, with an estimated population of 17 to 28 million feral and wild birds in Europe alone and up to 120 million worldwide.