Larus heermanni
tags: Heermann's Gull, Larus heermanni, birds, mystery bird, bird ID quiz
[Mystery bird] Immature (1st winter/second summer?) Heermann's Gull, Larus heermanni, photographed somewhere along the Pacific coast of the United States [I will identify this bird for you in 48 hours]
Image: Joe Fuhrman. I encourage you to purchase images from this professional photographer.
NOTE: Please name at least one field mark that supports your identification.
This species has a special natural history character that makes them especially vulnerable to extinction. Can you tell me what that is?
Heermann's…