The bird is an adult and most probably is the well-known wintering bird, returning to the area year after year (first seen in 2004-2005 if I remember well).
Also around was a single juvenile Common Gull which was actually the season's first in my patch. Also quite a lot of Great Crested and Black-necked Grebes on the sea, along with a Red-necked Grebe in the bay of Grignano. No sign of any diver though. About 5 Sandwich Terns were noisily patrolling the coastline, while other birds included a single Med Gull and a few juvenile Shags. Three Siskins passed overhead, giving their calls.
Juvenile Common Gull with Black-headed Gulls
In these days several Hawfinches are to be seen around the wider area of Barcola; usually they perch on the highest trees on view: