From now on, every Sunday’s wildlife photos will comprise ducks, for evolutionist John Avise has kindly offered to send weekly allotments of duck photos to get us through the pandemic. Each Sunday will feature one species of duck, and your job is to guess the species. I will put the correct answer below the fold, along with an interesting Fact About That Duck.
This will give you a chance, during our joint quarantine, to learn some of the many species of this awesome group, and to see their pervasive sexual dimorphism. John has about 21 species of North American duck, so that should keep us occupied for 5 months, and (knock on wood) perhaps the pandemic will have abated by then.
Here’s the Duck O’ the Day. What species is it? (Answer and fact below the fold.)
What’s that duck? Click “read more” for the answer and a Duck Fact.
Duck O’ the Day: The Lesser Scaup (Aythya affinis)
John’s Duck Fact:
This “diving duck” feeds by surface-diving and then swimming underwater, often in open bays. In winter, they sometimes congregate on the surface in large flocks called “flotillas”.
What? no scuba gear?
At first I thought it was a goldeneye, but realized it doesn’t have the signature white spot on the cheek.
I see John has decided to start us off with one of the trickiest duck identifications out there. Greater and Lesser Scaup are VERY similar. Many birders, even experienced ones, can’t tell the difference—and the other day I had to leave my first two scaup of the year as Scaup(sp.?) as, although I felt they were Lesser, they were too far out for me to be sure.
Greater (Aythya manila) is larger as the name suggests, but this is usually only useful for i.d. with a mixed flock (or perhaps I should say flotilla!). John’s superb first photo shows a key difference: the white wing-stripe only extends half-way down the wing in Lesser, as opposed to much further in Greater. This is difficult to see in the field, though, as they beat their wings so fast in flight. Easier to use is when a bird on the water stretches out a wing (or both) as the scaup in the photo is doing, although of course there’s no guarantee they’ll do this. Head shape may be best mark — note the tiny crest at the back of the crown, which Greater lacks. Finally, the iridescence on the head is green in Greater, more purple in Lesser, but this depends on the light and can be misleading — note the second photo!
I’m looking forward to this Sunday series. And it’s duck time right now where I am as the birds return this spring. Going out birding alone is not violating social distancing in my book if you give any people you may encounter a wide berth.
Very good! Thank you for sharing.