Possible Iceland Gull

[westwings at sisna dot com (Mark Stackhouse)]

David Wheeler, Laura Lockhart and I went out to the Bountiful landfill
Friday afternoon to look for the possible Iceland Gull reported by Dennis
Shirley and others. Putting aside my skepticism about whether or not
Thayer's and Iceland Gulls are really two species, and trying to forget the
pain of the "almost Iceland" gull at Bear River a few years ago, I thought
we should give this candidate a chance for our first state record . . .

The landfill was, as usual, full of gulls. This is, IMHO, probably the most
consistantly great winter-gull location in northern Utah, and perhaps in
the entire state. We watched the action around the garbage for about an
hour - mostly California's and Ring-billed, with quite a few Thayer's and
lots of Herring Gulls mixed in, and one beautiful second-winter Glaucous,
but nothing that looked even remotely like an Iceland. The tedium of
watching the feeding frenzy began to wear upon us, and knowing that there
are normally many gulls loafing on the ice on the ponds at the north edge
of the landfill, we opted for a change of scenery, and went to the
northeast corner of the landfill, where we could overlook the ponds.

There were, as expected, several thousand gulls on the ice. However, a
quick scan through the flocks didn't produce any likely candidates. A more
careful scan turned up a pale first-winter gull directly in front of us
which looked like it might have some potential. It was smaller than a
nearby Herring (good), but slightly larger than the California's (good
again), had dark pink legs and a dark bill which looked pretty stubby for a
Thayer's (also good). The problem was that the bird was facing directly
towards us, so we couldn't see anything of it's wings or tail, which are
critical for this i.d. We put our scope on the bird, but couldn't really
add anything to what we saw before, other than to note that the bill looked
a bit paler at the base (still good). The bird teased us with one oblique
look at it's wingtips when it turned slightly (they looked pale), but
really didn't cooperate. Then disaster struck - a fog bank rolled in from
the west, and in a few minutes, we couldn't see any of the gulls at all. We
waited for a bit to see if the fog would clear (it didn't), and then packed
up to leave, mostly convinced that this was probably the bird we sought,
but completely unwilling to call an i.d. on what we saw.

Just before we turned to leave, a huge flight of gulls came into the dump
from the north. Was this the flock from the ice? I couldn't see clearly
through the fog whether or not there were any birds on the ice. Many of the
birds which had flown by settled on the flat area to the northeast of the
active part of the landfill, close to our postion. We moved around for a
better view, and searched the flock. In the middle of the flock was a
strange gull, picking at the seed-heads of some weeds (is this "normal"
gull behavior???). Unlike our view of the bird on the ice, this one was
faced directly away from us. It had a very scaly pattern on the back, and
was generally pale overall. There was no overall difference in the color of
the primaries from that of the mantle or the rest of the wings - so much so
that my initial impression was that this might be a Glaucous-winged Gull
(except that the scaly back didn't really fit). The bird turned to give us
a full side-view, and YES!!, the bill shape and color showed us that this
was the bird we had seen on the ice. I quickly loaded my camera and began
taking pictures as we studied the bird. It stayed there for quite some
time, allowing us to study it in the scope, and to take some more pictures.
Eventually, I walked close enough to flush it, allowing us to see and
photograph the all-important open-wing view. I managed to shoot almost an
entire roll of film of this bird, and hopefully, the several flight shots I
took will come out decently.

In addition to the items noted above, this is what we saw:

Bill: Generally dark in color, especially black on the outer (distal) half,
becoming more pale towards the base, with definite dusky-yellow near the
base of both the upper and lower mandibles. The dark of the tip extended
farther towards the base along the commissure (the closure line of the
bill). The bill was relatively thin (like a Thayer's as opposed to a
Herring, Glaucous or Glaucous winged) and short. It had a somewhat sharp,
but not deep, gonydeal angle.

Eye: Dark

Head: Rather round and pale, with a few fine, diffused, dark markings throughout

Underparts: Mostly uniform pale tannish-gray, with somewhat less brown
tones than most of the Thayer's we saw. The undertail coverts were whitish
with darker barrings.

Legs: Dusky pink.

Upperparts: The mantle and wing-coverts were pale whitish-gray, with darker
gray edgings, giving a rather strong scaled or barred appearance. The
secondaries were somewhat uniformly pale gray - about the same overall tone
as the mantle and wing-coverts - with no noticeable difference between the
outer and inner webs. The primaries were very pale whitish-gray (paler
overall than the rest of the wing), with slightly darker gray on the outer
webs. The darker color on the outer webs was most prominent towards the
base of the primaries, fading to white towards the tip of the outer web.
The inner webs of the primaries appeared to be entirely white, even at the
tips. In flight, the secondaries appeared to be uniform in color to the
mantle and wing coverts - that is, there was no sign of the dark secondary
bar typical of Thayer's. The primaries were paler overall than the rest of
the wing, appearing rather translucent white.

Tail: Pale, whitish-gray, lightly barred, with no darker tail-band, or any
contrast in the general color from the rump, uppertail coverts to the tail
itself.

In our opinion, this bird is a MUCH better candidate for an Iceland Gull
than the Bear River bird was. All of the important features we noted
pointed strongly towards Iceland Gull, and none favored Thayer's Gull. The
things which cause me to lean towards Iceland Gull on this bird are the
overall color (much paler, grayer, less brown than most Thayer's), the bill
(shorter, noticeably paler at the base), the scaly, less-uniformly mottled
upperparts, the lack of a dark secondary-band in flight, the pale
primaries, with no dark on the tips of either the inner or outer webs, pale
gray outer primary webs (as opposed to the darker tan of Thayer's), the
translucent, whiter-then-the-rest-of-the-wing appearance of the primaries
in flight, and the lack of a darker tail or tail-band.

Hopefully, my photos will support our in-field (in-dump) observations. I'll
send the best to the Utah Birds website for posting as soon as I get them
back and scanned.

On another note, we also saw (and photographed) a very odd adult
Ring-billed Gull, with an entirely white tip on its right wing only (the
left wing was completely normal).

For those who don't know how to get there, the Bountiful landfill can be
reached by going north on 1100 West from 500 South (there's an exit off
I-15 at 500 South - 1100 West is west of the freeway) to the stop sign at
1600 North. Turn left on 1600 North and follow the road around to the
landfill entrance. Most of the action is at the north side of the landfill
(just look for the fresh garbage and flocks of gulls!). Don't forget to
check out the ice to the north of the dump (you'll need a scope).

Good birding!

Mark Stackhouse
Westwings, Inc.
1432 Downington Ave.
Salt Lake City, UT 84105
tel./fax. (801) 487-9453
westwings@sisna.com


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