Pigeons at Union Station in Toronto.
Pigeons and doves constitute the bird clade Columbidae, that includes some 310 species. In general, the terms "dove" and "pigeon" are used somewhat interchangeably, however, in ornithological practice, "dove" tends to be used for smaller species and "pigeon" for larger ones, but this is in no way consistently applied, and historically, the common names for these birds involve a great deal of variation between the terms.
The species most commonly referred to as "pigeon" is the Feral Rock Pigeon, common in many cities.
and if you want more pigeons, a little video clip…