Many of my blog posts are trip reports or contain mainly photos. Every once in a while I also write in-depth articles about specific topics. To make these articles easier to find, I will list them here separately.
Identifying nearly-fledged Herring Gulls and Lesser Black-backed Gulls in the field
Deciphering the black mark on P9 of Black-headed Gulls
Bill and eye characteristics in European Herring Gulls
Primary pattern variation in individual European Herring Gull
Ring-billed Gulls vs Common Gulls: comparison from a Dutch perspective
Adult American Herring Gulls, seen from a Dutch perspective
Tertial spots in sub-adult and adult gulls