Rock Dove (Rock Pigeon)
There are several species of pigeons. In the streets of Russian north cities, every day we see blue rock pigeons. Wild blue rock pigeons live in rocky mountain areas. It was found out that pigeons, as well as sparrows, once lived in mountains. But with the development of the civilization, with construction of multi-storied buildings, these birds began to occupy cities. For them, huge stone buildings are similar to rocks, and the neighborhood of man turned out rather favorable because of an abundance of food remaining from people.
The courtship display of pigeons include ritual of soaring flight with wings raised angularly, and a "boastful" ritual on the ground when a male inflates his breast, bows in front of a female and coos. Some individuals very smartly use the same ritual in front of people — to “earn" some food in this way.
Pigeons of both sexes (!) feed their young with “pigeon milk". It was established that it is enough for them to see a nestling and their organisms start producing the hormone which drives the production of the “pigeon milk”.
Thanks to high speed of flight and surprising ability for orientation, domesticated pigeons, since long time ago, were used by people as a means of communication.