Jaegar sp, Cherry Creek State Park (Arapahoe county)

[Ben S]

Hi all -

I went to Cherry Creek's Lake Loop this evening hoping to see the group of Black Scoters recently reported (I did not). I was pleasantly surprised to see a Red-necked Grebe and two latish Sabine's Gulls out in a large mixed gull/grebe flock. Also a dark morph Jaegar sp. The bird spend its whole time in the middle of lake northwest of Lake Loop in a huge flock of gulls. Oddly enough, it never harassed any gulls when I was observing. Told from immature larus gull by obvious yellowish pale back of neck, small bill, rounded head, upright position in water, and, when it spread it's wings, dark underwing with white on tip. It also had very long wings relative to size, and bent and pointed wing shape, evident when bird spread wings. I have photos, unfortunately they are were digiscopped halfway across the reservoir after sunset, but hopefully they will help demonstrate the birds shape, distinctive wings. I am thinking Parasitic or Long-tailed, not Pomarine, due to its size (same size or a bit smaller than Ring-billed Gull from bill to tail), and other features.

Ben Sampson

Centennial, CO