A flock of pigeons feeding. Their grey colour varies from light to dark with black stripes on their tail and green/violet head.
Mostly cities. Europe, but are spread all over the world.
These pigeons are from my trip to Rome. We call them "golobi" (pl.) or "golob" (sg.). In Ljubljana I noticed some of the pigeons with wounds or scars, which shows a sign of molesting, some even without one leg. I even remember seeing one man in Delft (Netherlands) kill a pigeon in front of me without any shame at all and then put it in his plastic bag and ride away.