A few images of adult birds in winter plumage
Common Gull ~ ad. W
Ad. W - Wing
Probable Adult Male Wing
Note: Male averages larger than female and generally with largest white mirrors on P10-P9.
P9 in male 35-50 mm - female 22-40 mm.
Small percentage with P8 mirror on inner web.
Now compare to ......
2nd. W - Wing