Black-headed Gull
Chroicocephalus ridibundus

Black-headed Gulls were formerly considered part of the Larus genus, but have recently been split into a new genus, Chroicocephalus One of the most common gulls here in Switzerland, they can be found over lakes and sometimes rivers. The first is a winter adult and the second is a 1st-winter bird with the Alps in the background.
 

1-3: Neuchâtel, 20/01/2008.