Date: 4/29/25 9:17 am From: Peter Pyle via groups.io <ppyle...> Subject: Re: [EBB-Sightings] Aechmophorus, etc.
Thanks Ethan, always enjoy your posts!
Your reflections on the Aechmophorus caused me to dredge up something I wrote a few years ago on this for my Marine Sanctuaries Beach Watch column.
Happy spring birding to all, Peter
How often do you see Western or Clark's grebes (WCGRs) flying? Sometimes, for short low flights, but not much. Their short and rounded wings seem to barely keep their heavy bodies aloft. Well, what I consider one of the great underappreciated occurrences in our local bird world goes on each spring in late April through mid May. Perhaps you've noticed large rafts of WCGRs off some of our beaches; I've seen them off Naples (Half Moon Bay), Funston, Stinson, and Drakes beaches and suspect they occur elsewhere off sandy shores in semi-protected waters. What are they doing? Sometimes I'll count several thousand one day and then, after a calm clear evening, they'll all be gone the next day. So they are staging for migration, and I presume all take off together to fly high in the night-time sky to inland breeding locations, maybe as far as the great Basin and Prairie provinces of Canada, which means they are flying over the Sierra Nevada! Really? WCGRs? What do we know about this? I just checked the Birds of the World account and it is mentioned that they move these directions and distances but there is practically nothing else about these flights. Seems like a good project for someone with Automatic Recording Units (or ACUs) to figure out what pathways they may be taking.
On 4/29/2025 8:50 AM, Ethan Monk via groups.io wrote: > Over the weekend I took advantage of a windless Richmond to stare out > at the bay from Pt. Isabel. Notable were 6 Common Loons (5/6 in full > alternate) and 1 basic-plumaged Red-throated Loon, and about 20 each > Forster's and Elegant Terns. But interestingly were Aechmophorus > grebes. I counted shy of 500 total, and among those close enough to > identify to species, I counted 150 Western:40 Clark's, with most rafts > being predominantly Western, spare a small monotypic group of Clark's. > Typically on the open bay in Richmond, Clark's Grebes dominate, e.g. > in November here I had 35 Western to 100 Clark's, and as recently as > February here I was counting 30 Western to 70-80 Clark's. Hell, Oct. > 27th of last fall I counted 151 Clark's and 18 Western! So this > inversion of the typical ratio is notable, but apparently not unusual > and the increase in Western Grebes is something I have noticed in > previous years, typically in late March and April. It seems to me to > be most likely migrating Western Grebes are inflating the local > numbers as they move into the bay from the ocean. If something to this > effect happens in fall, I have not yet been a knowing witness! > > In other news, on Brooks Island as has now been well reported, there > are good numbers of Elegant Terns, with a hundred plus engaged in some > form of courtship. Courtship doesn't necessarily entail breeding, but > it seems promising. Otherwise, about 140-150 or more Caspian Terns are > breeding here at the traditional colony, as are ~300 (rough count!) > California Gulls. Also of note were 3 Snowy Plovers sporting full > alternate, chasing each other around a high spot on the island below > the copse of dead pine trees. Successful nesting here seems unusual > with the number of gulls, but something to keep an eye on! > > It has been a good year for Lawrence's Goldfinch as many have noticed. > On April 19th I found a handful of singing males in Curry Canyon at > the state park boundary, but more notable was a singing male > Lawrence's Goldfinch at the house with the big eucalyptus on Byron > Hotsprings Rd on the 20th. By the airport. Since February, there has > been a White-fronted x Cackling Goose hybrid on Bethel Island. I last > saw him on April 20th with 80 White-fronts. On April 24th most of the > geese, and the hybrid, were gone. > > Ethan Monk > > > > >
