Steve N. G. Howell's "Gulls of the Americas" is an excellent book, with a few pages of pics per species, including various ages, birds in flight, resting, etc.
Dave Cameron Denver On Thursday, February 13, 2020 at 5:48:04 PM UTC-7, Jared Del Rosso wrote: > > 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. > > - Jared Del Rosso > Centennial, CO > -- You received this message because you are subscribed to the Google Groups "Colorado Birds" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/cobirds/1a540a33-940f-4007-99bd-fbbd0f338a07%40googlegroups.com.
