Just for reference: comparison of primary patterns in adult Dutch Lesser Black-backed Gulls (Larus fuscus graellssi, Dutch intergrade), all from different individuals, mix of male and female.
Details to look out for are:
- Presence, absence and shape of mirror on P9/P10
- Presence or absence of black on primary coverts
- Number of primaries with black
Images were taken during ringing activities in the IJmuiden Forteiland gull colony, the Netherlands, May – June 2018.
Click for a larger view.