Pigeon (Columba livia)

CC-BY Kostis Tzortzakakis

Looks like
The colour of the pigeon varies and can be grey, white, brown (or a combination of these), with darker grey, green or purple shades or black spots. The pigeon is a medium-sized bird (ca. 30-35cm). It feeds on seeds, nuts, and leftovers of humans. Its voice is a deep cooing.
Where and when to spot it
The pigeon is very common and well adapted to city life. It forms large groups in squares and parks and often sits on wires and on buildings. It uses buildings, balconies, ridges or even external aircondition devices to build its nest.