05 September 2012

2nd Cycle American Herrings in Michigan

Here are a few 2nd cycle Herrings photographed in Berrien County Michigan on 01 September 2012:

2nd cycle American Herring Gull.

The 10th primary is still not fully grown along with several inner secondaries, but aside from that, the 2nd prebasic molt is almost complete.

Same individual as above.
The bird below has a band that eluded me in the field (hence the reason for large color bands used by European ringers):

2nd cycle American Herring with leg band (juvenile in background).
I first found it standing in the water where the band was concealed:

Same individual as above.
The only PB2 flight feathers still growing are the secondaries adjacent to the tertials and the two outer primaries:

This next 2nd cycle had rather pale upperparts which made me consider the possibility of a few Glaucous genes. In particular, the greater coverts seem white-winged-ish to me, but everything else is within range for smithsonianus. PB2 is not as accelerated as in the individuals above (note the short wing projection):

2nd cycle American Herring Gull.

Are the upperparts too pale for a pure bird or is this the result of bleaching?

Finally, the 2nd generation upper scapulars on this last bird are somewhat accelerated. Also note the unmarked vent and lower belly area - this is more of a late October, early November look:

2nd cycle American Herring.

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