ML645872757

觀察細節

At 9:41 AM I noticed a small flock of gulls flying to the west. Under the diffuse light of the overcast sky, I noticed one gull's plumage was light overall. I immediately thought it was a first-winter Iceland gull. I started taking photos continuously as the gulls continued flying west until the rear views were not adding useful identification information. I then examined the photos though the camera viewfinder and saw that the outer primaries were slightly darker than the inner primaries. That suggested Thayer's, a species I had seen only once in March 2017. I downloaded a few photos to smartphone and then send to Aidan K for his review. He in turn circulated the images, and responses agreed that Thayer's was possible. Later when home, I post-processed several photos with views that might be useful for identification. These are included in this checklist. The photos show a light brown-gray bird with outer primaries and secondaries that are darker than the inner primaries. The coverts show checkering. The tail appears to be light gray-brown tipped in white. The bill is all black. The face is not well shown, but they eye and cheek are dark. Legs and feet were not visible. The last image shows the difference in its appearance from a typically-dark immature AHGU. (Update: I was intrigued by the report by Dan E and Sean W of a Thayer's gull observed at Ocean Beach in New London on the afternoon of this same day. https://ebird.org/checklist/S286136001)