Female Common Goldeneyes with Group of Male/Female Greater Scaups? (1 Viewer)

Hey there!

I'm new to birding, so there are still many basics I don't know yet. So bear with me if I'm missing some obvious stuff.

Yesterday, I was out at a seaside park in Fukuoka (which in south-west Japan). I saw a big flock of ducks off the coast (maybe 100 or so) and identified them to be mostly greater scaups. Among them though, I saw two very different types of females: one was clearly greater scaups, but the other looked like female common goldeneyes (in particular, there was no white at the base of the bill). However, there wasn't a single male common goldeneye to be found. I was surprised by this distribution... Is this a common behavior for female ducks to group up with males/females of another duck species but with no males of their own species? Alternatively, is it more likely that I've misidentified winter->summer transitioning plumage of female greater scaups as a female common goldeneye?

Thanks in advance for your help!

Danny

A first winter male would resemble an adult female in terms of plumage but with a much reduced or no white patch at the base of the bill.

The bill size and shape is different between the two species.

Thanks a lot! I guess they were all grater scaups with a handful of first-winter males.

Until now, I've been unfamiliar with "first winter" as a term, so I found a great pdf with birding terms including that (https://sora.unm.edu/sites/default/files/27-43 OB Vol 18#1 Apr2000.pdf).

I'm learning! So, thanks a lot!

No worries. Sorry, perhaps I should have explained the term but at least it gave you the chance for a bit of research!

Welcome to the forum by the way.