10 October 2012

Another Cinnamon Ring-billed

Here's another juvenile Ring-billed Gull showing cinnamon tones throughout:

Rainbow Beach. Chicago, IL. 06 October 2012.
It shows limited post-juvenile molt of the scapulars (PA1) and has retained a good amount of juvenile chest, neck and head feathers.

Compare this to the first basic individual below:

Tinley Park, IL. 27 September 2012.
It's hard to believe these are both hatch-year birds given the amount of post-juvenile molt this second individual exhibits. Most of the scapulars have been replaced along with many median and some lesser upperwing coverts. Most urprising though is the renewal of the tertials via PA1 - this is an exception in first cycle birds. A possible explanation for the difference in these two birds is "early hatch" versus "late hatch" coupled with the former being somewhat delayed and the latter advanced.