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Quick! Get yourself to Brigham City in Box
Elder County for a great waterfowl study opportunity on a relatively
tough and uncommon species for Northern Utah--the Greater Scaup. Glenn
Barlow and I saw many--up to 20--this morning from 10:00 to 11:30 at the pond on
UT 90 on the east side of town. The scaup were also there late on Sunday
afternoon, but after I picked up most of the field marks, my study
opportunity collided with dusk and I had to return this morning for a
second look with reinforcements.
There are several reasons why this is a great
study opportunity. First, Lesser Scaup were also present. We
could agonize and compare every nuance of every field mark,
including the white stripe on the primaries and secondaries, depending on
which species stretched its wing. Here's a gem from Kaufman's
Advanced Birding: "If you are fortunate enough to visit a pond or
bay where both species are present, it would be most worthwhile to spend a few
hours with a telescope studying their head and bill shapes from all angles,
watching the apparent changes in head shape in both species."
Another factor that helped our study was
the bright light at our backs the whole time. Brigham City is
experiencing the same fog as the rest of the Wasatch Front; however, by the
time we arrived, the fog had lifted to the mountains and the sun was
shining. The only minor impediment was that thin wisps curled up off the
surface of the water the whole time we were there. Once we realized it was
the water and not our lenses fogging up, we could deal with the challenge.
Here's what we saw on the male Greater Scaup
compared to the Lesser: a lower, more rounded and arching crown, a bigger
and broader bill with a more extensive black tip, cleaner and sometimes
immaculate white sides, and larger overall size. Glenn picked up the
overall body size difference much more clearly than I did, but I was greatly
comforted by the second line in the chapter on scaup in Kaufman: "The size
difference is not strikingly obvious even when the two are together..." So
if you think the Greater ought to look greater than the Lesser and the Greater
doesn't really look greater, don't fuss over it greatly. We noticed
that at no time did the Greater Scaup ever appear to have a point on the crown
aft of the eye. The light conditions were so good that we even picked up
the green metallic cast to the Greater Scaup's head. The Lessers never
really showed a metallic color--they just looked dark, as if their head plumage
absorbed light instead of reflected it.
Once we studied the males we moved on to the
females. Whether or not the gals were sleeping with heads tucked,
subtle differences began to emerge. The Greater female's head was more
rounded and sloped in a low arch. The color of the plumage was a
darker, more chocolate brown, and the white 'kidney bean' aft of the bill was
more distinct. The best look I got of the longer white stripe on the
primaries was on a female Greater, and the stripe obviously extended along
her secondary flight feathers and well into the primaries as she stretched
one wing. I later watched a Lesser female stretch in the same way, and the
white wing stripe appeared truncated in comparison.
I found it very difficult to count the Greater
Scaup. I counted four times and came up with different numbers from 14 to
20. The Greater Scaup were in a large (100-150) and constantly moving
mixed raft, including the Lessers, and I was only willing to count a particular
duck as a Greater if I saw it in a 90 degree profile view. Sometimes
I saw profiles 20 times, sometimes 14 times. I believe there were more
females present than males.
Here's the other birds we saw: a male and a
female Barrow's Goldeneye, 35 Ring-necked Ducks, Common Goldeneyes, American
Wigeon, Gadwall, Mallards, Green-winged Teal, a Canada Goose, a Pied-billed
Grebe, one female Northern Shoveler and a Great-blue Heron. Last
night, I also saw three Wilson's Snipe and two muskrats. I suspect this
pond gets a lot of waterfowl traffic because neither the Mallards, teal, nor
Ring-necks were there last night.
Here's how to get there. From points along
the Wasatch Front, take I-15 to exit 364 (Brigham City, Logan, and UT
91). Turn east. UT 91 intersects Main Street in about 2
miles. Turn left (north) on Main Street and drive to the Brigham
City Tabernacle. Turn right (east) after the tabernacle on UT
90. Drive .9 miles and look for the pond on your
left. If you're driving from Cache Valley, take US 89/UT 91 past Mantua
and take the first Brigham City exit (UT 90). You'll find the pond on your
right in approximately .2-.3 miles. There's a good, wide pullout
along the south side of the pond on a road that doubles as an entrance to a
gravel pit. You'll likely have sand and gravel trucks thundering past as
you study.
Kris
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