Heermann's Gull heermannii

(last update: 23-01-2018 )

Coordinators:
John Cant
Mars Muusse

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1cy June
1cy July
1cy Aug
1cy Sept
1cy Oct
1cy Nov
1cy Dec

2cy Jan
2cy Feb
2cy March
2cy April
2cy May
2cy June
2cy July
2cy Aug
2cy Sept
2cy Oct
2cy Nov
2cy Dec

3cy Jan
3cy Feb
3cy March
3cy April
3cy May
3cy June
3cy July
3cy Aug
3cy Sept
3cy Oct
3cy Nov
3cy Dec

adult Jan
adult Feb
adult March
adult April
adult May
adult June
adult July
adult Aug
adult Sept
adult Oct
adult Nov
adult Dec

1st > 2nd cycle (2CY): August

By August birds are in the last stage of the PB2 moult (complete moult in summer from April - August), Outer primaries missing and growing.
Commonly, birds can be found missing some central median coverts (MC) or missing upper tertials (TT). This is an indication for the start of the partial autumn moult. This moult in inner wing-coverts and upper tertials will result in 2nd winter birds, when standing, showing an (obvious) grey bar over the wing. Grey upper tertials contrast with the faded brown lower tertials. Some innermost greater coverts (GC) and random some lower lesser coverts (LLC) are often included in the partial autumn moult as well, hence, will appear grey in winter too.