Date: 2/13/20 4:48 pm From: Jared Del Rosso <jared.delrosso...> Subject: [cobirds] So Many Gulls - Centennial (Arapahoe)
I've lived in Centennial for four winters now. This winter, like the last several, significant numbers of gulls move west to east around dawn and back again at dusk. Tonight, the movement was significant, with several large kettles of them forming to rise, gracefully, on thermals and even more just passing by. I didn't count tonight, but the movement spanned thirty or so minutes tonight.
I rarely identify them and struggle to do so from far below. Most are, of course, Ring-billed. There were larger ones mixed in.
I'm located near Arapahoe and University in Centennial. Most of the movement occurs right over a line of transmission towers near deKoevend Park, though of course the birds drift north and south of that. One wonders where they come from at night (Aurora Reservoir, which is almost due east?) and where they head.
Are there any sources on ID'ing gulls in flight?
Also tonight: a local magpie seemed to be gently, but conspicuously singing. It was especially endearing, given how noisy and brazen these birds usually are.