What duck is this duck?

[Dan P]

 

Taken 3-27-2021 at Santa Fe Dam Recreation Area in Irwindale, CA (Los Angeles County).

Is this a domestic duck or some kind of teal hybrid?

[Tony Leukering]

It's a female-plumaged scaup

[Clip]

1 minute ago, Tony Leukering said:

It's a female-plumaged scaup

Curious why no Greater or Lesser call on this one? The photos seen good enough.

[Dan P]

Thanks.  I just got my first photos of Scaups last week at two different locations, and I've been struggling with identifying whether the males are Greater or Lesser.  

Now that I look at the females, I believe the bird pictured here would be a Greater Scaup -- which I believe is the only photo that I have of one.

[Clip]

3 minutes ago, Dan P said:

Thanks.  I just got my first photos of Scaups last week at two different locations, and I've been struggling with identifying whether the males are Greater or Lesser.  

Now that I look at the females, I believe the bird pictured here would be a Greater Scaup -- which I believe is the only photo that I have of one.

Tony L. who has written papers on the id of greater v lesser scaup is saying I believe that it cannot be determined if this is a greater or lesser scaup.

[Dan P]

Okay thanks.  I will just leave my scaup identifications as Greater/Lesser Scaup -- Aythya marila/affinis and upload the photos with my eBird checklists.

[Tony Leukering]

On 4/3/2021 at 2:23 PM, Clip said:

Curious why no Greater or Lesser call on this one? The photos seen good enough.

The second photo's angle provides no certain data and the first shows a bird that is probably foraging, making head shape unreliable for ID.

[Avery]

11 minutes ago, Tony Leukering said:

The second photo's angle provides no certain data and the first shows a bird that is probably foraging, making head shape unreliable for ID.

Just for clarification and peace-of-mind, in foraging scaup, is head shape viewed from behind unreliable as well as profile head shape in foraging birds?

[Tony Leukering]

1 minute ago, Avery said:

Just for clarification and peace-of-mind, in foraging scaup, is head shape viewed from behind unreliable as well as profile head shape in foraging birds?

That's a superb question, but one to which I lack a superb answer. I would imagine that it should be, as, unlike the malleability and ephemerality of crown shape, the jowls (see here for those who haven't seen this essay) are the result of bone structure (at least, I think it is), so should be more reliable, even when crown shape is altered by diving ducks compressing their plumage prior to diving. Depressingly, I haven't even thought about looking at that in the field. I will remedy that.

[Clip]

18 hours ago, Tony Leukering said:

The second photo's angle provides no certain data and the first shows a bird that is probably foraging, making head shape unreliable for ID.

Just wondering because you called the one I posted a few months ago without hesitation even though it had been foraging. I know this not from a photo but because I watched it it doing it live and in person. I would think just the nature of duck feathers would prevent too much alteration. I changed my ebird list from Greater to Lesser on your call from a photo over riding my own opinion based on live field observation. Now I'm just wondering if I did the right thing.