Update Dec 2007: A chance browse through the photos from this date allowed me to realize that I had actually digiscoped this same individual... new images added at the bottom of the page, with a comparative Yellow-legged Gull from Newfoundland:
These pics were taken on March 15, 2006 in the Coastal Plain near Houston and Galveston, Texas; my memory of the event is that I saw these two darker-backed large gulls and decided to take some record shots, hoping to then get closer for better looks - but moments later all the gulls were spooked, and when they re-settled I never saw either bird again:
The left-hand darker gull is clearly an adult California Gull, but what is the right-hand bird?:
Below I've "moved" the CAGU over next to the other gull for comparison:
This is the only other pic of these birds, and again I've "moved" the CAGU over next to the mystery gull:
Note the following data extracted from Steve Howell's BIRDING article on gull mantle shades:
| L. californicus albertaensis |
5 - 6 |
| L. michahellis michahellis | 6 - 7 |
| L. californicus californicus | 6 - 7.5 |
| L. michahellis atlantis | 7 - 8 |
| L. fuscus graellsii | 9 - 11 |
Update Dec 2007: I have just discovered that buried among the 100+ images I took that day were a handful of digiscope pics of this same individual:
For Comparison here's an adult Yellow-legged Gull from Newfoundland:
