[TN-Bird] Scaup Identification
- From: Michael Todd <birder1@xxxxxxxxxxxxx>
- To: TN-Bird Listserv <tn-bird@xxxxxxxxxxxxx>
- Date: Thu, 1 Jan 2015 08:12:46 -0800
Following the recent photos from TVA Lake I posted, it has been requested I
post a few pointers along the lines of Scaup identification since a lot of
folks don't get to spend much time really looking at them. For those pretty
familiar with Scaup.......sorry for wasting your time! :")
Scaup identification can be very tricky of course, but luckily has come a long
way since the days of Peterson and the Golden Guide! In my opinion, Sibley and
Kaufman's Advanced Birding brought this subject ahead light years for the
birding public. Sibley in particular, goes into all the nuances of this
identification, such as the change in head shapes of actively diving birds, and
sleeping birds especially. I imagine most birders here have Sibley, but it is
really a must-have for learning Scaup on your own.
Lesser is pretty widespread across the state, and is liable to show on any
sizeable body of water. Greater can too of course, but tends to be much less
common, especially away from the larger reservoirs like KY Lake. One of the
biggest problems, Scaup viewing often is at long distance, which can make the
process a lot tougher, especially if you aren't somewhat familiar with them
beforehand. Birders with some time winter birding on the coasts have a definite
head start with Greaters potentially! That being said, Greater can show up
pretty much anywhere, even small bodies of water. The old habit of assuming a
Scaup is a Lesser isn't really valid anymore.
TVA Lake in Memphis (which isn't remotely close for most of the readers here I
know) is an exceptional place to really learn your scaup. In my experience,
granted I don't bird it as often as some of the Memphis birders, there are
almost always Greater Scaup present in the scaup flock; though at times there
are no Scaup there. Viewing here is close enough that anyone with a scope can
get some pretty good looks even if the birds are on the back side of the lake,
compared to my viewing at Reelfoot or KY Lake where the Scaup rafts may be out
at the edge of vision. Reelfoot especially is funny, we get huge numbers of
Scaup there, but very few Greaters. On the CBC this year, liteally my count for
Lesser Scaup was on the order of 8000. Viewing conditions were the best I've
ever seen there, and most of the 8000 were viewable well enough to ID, and had
exactly 1 Greater! On little TVA Lake the other day, had 130 Scaup, 110 were
Greater!
As far as the actual ID, as the saying goes a picture is worth a thousand
words. I was mainly shooting the Long-tailed Duck at TVA Lake the other day,
but came away with some nice Scaup comparisons. If you look at a few of those
photos, the majority of Scaup in all of them are actually Greater. This ID is
always easiest for me, when the birds are actually sleeping. Sleeping scaup are
easiest with a nice side profile, where the narrow, triangular head of Lesser
is markedly different than the big flat or very gently curved head of a
Greater. A few sleeping birds can look intermediate, but most are obvious one
way or the other.
Actively diving scaup are the hardest, as they compress the crown feathers
which can give Lesser a much more Greater looking head shape. Greater though,
never shows the high peaked look at the rear crown of a relaxed Lesser. Head
on, the cheeks and even the crown of Greater are much thicker in comparison,
one of my photos has a female Greater showing this well, to pretty dramatic
effect. There are other differences but there is overlap on most of this, such
as the size of the bill and nail. Female Greater are more likely to have the
obvious pale spot on the ear coverts, but this isn't absolute. The whiteness of
the back of adult males is also something that can change with angle etc, but
can be an indicator of a Greater among Lesser. The gloss of the head of males
is the absolute least reliable thing. Either can show purple of green, though
in profile at the same angle a head consistently different than those around it
is worth looking at it a little closer.
My apologies for what turned into a much longer post than I anticipated, for
those of you who actually read it all. Some scaup are still hard to put a name
too, especially from just a photo or two. After really paying attention to them
though, they do get easier.
The head shape differences in particular show pretty well in some of those
recent photos I posted, wish I had a good head on view of a Lesser, but not
seeing one. Lots online of course with a search. Those photos, most with
captions below start here again for those interested in this topic:
http://www.pbase.com/mctodd/image/158686830/original
Be interested in others comments or experiences along these lines
Good birding!!
Mike Todd
McKenzie, TN
birder1@xxxxxxxxxxxxx
www.pbase.com/mctodd
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