The bird generally called a “pigeon” is the Rock Dove, which has escaped from domestication and returned to the wild. There are many variations in plumage, both in color and pattern, but those closest to the ancestral wild form are grey in color, have two black bars on the wings, and green-purple iridescence on the breast. Adults have a white knob on the upper bill but on juveniles it is not very white (above photo). Males do not sing much except for a soft, low “goro-poppo” during the mating season, but chicks give a sharp “pii-” cry.
Play birds singing
Common and widespread throughout central Asia and elsewhere, the Rock Dove originally nested on narrow ledges of cliffs. When humans began building structures, the Rock Dove came to nest on the ledges of those structures, leading to its capture and domestication by humans. In addition to being used to carry messages, the birds were kept for ornamental use and for food, but they escaped domestication and now live in the wild throughout the world.
It is classified as a non-native species Rock Dove (Kawarabato) in the Check List of Japanese Birds (The Ornithological Society of Japan). They were fortunate in that there were few natural predators near human settlements, and since their main food source is plant material (seeds and fruit), they could live on the food they received from humans.
As a result of their tendency to gather together in large flocks and to nest in people's homes and train stations, they have come to be regarded as pests, but they are a source of prey for raptors, including the Peregrine Falcon and the Northern Goshawk, which hunt near urban areas.
In Japan, the native species Oriental Turtle Dove also now lives in urban areas and is unafraid of humans in contrast to the time when it was known as a “mountain dove.” There are several differences between them however. The Oriental Turtle Dove does not gather in large flocks, nests on trees, is sometimes migratory (a summer bird in Hokkaido), and when gliding, its wings remain horizontal (in contrast to the Rock Dove whose wing tips rise to form what looks like a “v” shape).
As explained in the profile of the Oriental Turtle Dove, they can breed at any time of year if their food source, namely plant seeds and fruits, is available, so scenes of courtship and mating, as well as parents raising their young can be seen throughout the year. The same is true of the Rock Dove. They also share the ability to drink water with their head down, unlike other birds. And, they often lose their feathers too. If you know that birds molt (the process of shedding old feathers and growing new ones) after breeding, you can understand that since doves can breed several times a year, they can also be molting at any time. And, it may be that having such a body, which sheds feathers easily, is the result of them often being the target of raptors (having feathers that shed easily increases the possibility of escape when being attacked by a raptor).
Since they can breed even in fall and winter when insects are scarce, mating can be observed in any season.
A male showing off the iridescence of his breast feathers is a keynote feature of courtship displays. Even males with color and pattern variations different from native species puff out their chest to appeal to a female.
Canon sites where this bird is seen