Re: Summering Scaup Flock at Albany Bulb


Ethan Monk
 

Hi Alex,

Thanks for the email! Since this seems at least partially directed at my backhanded eBird checklist comments, I figured I should respond in part (please don't take my checklist comments too seriously in there. Anything I find really important I'll put in an email here. All my comments meant is that people have the tendency to see 1-2 Lesser Scaup in a flock of Greaters, and extrapolate more Lessers into the picture). That being said, I would agree with you that there are several Lesser Scaup in the (a?) Scaup flock at the Albany Bulb/Pt. Isabel--I'll assume it's one flock sharing both locations. I think I've seen conclusive pictures of 2-3 Lessers. From my perspective, the majority of the flock has been Greater but I wouldn't feel confident in saying *all* of them have been Greater. While I do scope through them looking for the odd Lesser, as significant numbers of Lesser do winter here, I make the assumption that summering Scaup in the bay's northerly end are Greater (and vice versa with Scaup on the South Bay's salt ponds, which I know less about) and so I spend less time picking through them as I would in winter.This is probably something I shouldn't be doing.

We know that, historically, Scaup summering on this section of bayside have been almost exclusively Greater. I think you could say that Greater Scaup are the expected summering species in deep saltwater in much of Northern California? Whether or not the Lesser Scaup now are this year's exception or something previously overlooked, I don't know. If you'll notice, summer Lesser Scaup reports from the Albany-El Cerrito area in eBird are mostly exclusive to this year, but whether or not they've been overlooked in previous years we might never know.

To deal with the flock that's there right now--assuming they've been the same birds all summer, there are at least 18 Scaup around. We know from photos a couple are Lesser, sure. Telling how many are Greater from photos is harder, as generally people have a reluctance to photograph common and expected ducks, especially when they are in rather dull and tattered alternate. So I wouldn't make a blanket statement that since all of the 3 or 4 conclusive photos we've seen have been Lesser that the majority of the flock is Lesser. I'm willing to accept the possibility that the majority of the flock could be Lesser (as unlikely as that would be) but I think this is something that needs more study before we can say anything conclusive. I don't think just one photo of one Greater Scaup will cut it here.

Luckily for us, the flock should stick around for a while longer, and we all have a chance to figure out what's going on here. Greater Scaup are a rapidly declining species, so perhaps Lessers are moving in to fill in for the lack of Greaters? Anyway, I'll change my eBird lists so that half of the flock is a slash. I'll update them further as we find out more.

Thanks!
Ethan Monk

Join EBB-Sightings@groups.io to automatically receive all group messages.