Verification of Unusual
Rec. # 2011-06
|Scientific name:||Larus glaucoides kumlieni|
|Date:||3 January 2011|
|Time:||Approximately 1:40 PM|
|Length of time observed:||20 minutes|
|Location:||Lee Kay Ponds, on the south side of California Ave. about 110 yards east of the gazeebo.|
|Latilong:||Unknown, 40 44'21.47"N, 112 02'19.44"W (generated by Google Earth)|
|Elevation:||4228 feet (generated by Google Earth)|
|Distance to bird:||about 110 yards (generated by Google Earth)|
|Optical equipment:||Nikon Premier binoculars (Cliff-10x42 / lisa-10x32), Swarovski 80mm HD scope at 20-60x.|
|Weather:||It was clear but with some haze/smog that diluted the sun's rays.|
|Light Conditions:||Sun was behind birds but high in the sky so birds were somewhat backlit. When first observed the sun was directly behind the bird but we moved to the gazebo which put the sun at an angle making color discrimination better.|
|Description: Size of bird:||See description below|
|(Description:) Basic Shape:||See description below|
|(Description:) Overall Pattern:||See description below|
|(Description:) Bill Type:||See description below|
Field Marks and
Transcription of field notes written on 7 January 2011; text in parentheses
added for clarification at time of preparation of report):
Roosting on ice with California Gulls. Facing mostly away. Adult
-size slightly larger than California Gull on ice and in flight
-Mantle very pale gray; contrast with tertial crescent and scapular crescent slight; obviously paler than Herring Gulls and Ring-billed Gulls (both species were present for comparison)
-underparts white (clean white with no dark smudging)
-Legs pink - not as deep pink as Thayer's Gull (this was observed by Lisa only)
-Perched; wing appeared white at a distance. Some gray visible through scope. The gray was very pale, not visible in binocs (this is a description of the gray in the primaries, not the secondaries/coverts)
-During wing stretch Lisa saw the primary pattern briefly. There was a very limited amount of gray. Exact pattern not noted but clearly less gray than Thayer's show black. (Cliff did not see the open wing)
-In flight primaries looked white. At close range the pale gray was visible.
-Lisa noticed a deep chest and wide based wings (not observed by Cliff)
-Head was white with a little streaking - Cliff noticed the streaking was crisp (not blurry or smudgy as typical of Thayer's)
-Nape had more dense streaking (than head)
-Head rounded with no hint of being squared front and rear. Eye was set way forward towards bill from center. Eye did not appear small.
-Bill dull yellow with reddish gonydeal spot.
-Bill short and narrow with very slight bump at gonys (not observed by Lisa)
-Forehead looked steep
-Primaries were wider and more steeply tapered than other gulls, similar to Glaucous-winged Gull (in shape).
>>>>>>>>>>>End of field notes.
See Behavior for details of the observation.
This was a smallish adult larus with gray mantle, white underparts, white tail with no hint of dark markings, and yellow bill with reddish gonydeal spot. It wasn't much larger than CAGU in direct comparison and had a mantle that was obviously paler than Herring and Ring-billed Gull in direct comparison.
It had white primaries with very limited pale gray markings that were darker than the mantle shade but paler than Glaucous-winged Gull's primaries; the gray was much paler than the gray sometimes shown by Thayer's and obviously more limited. In flight Lisa recalls seeing a couple dark stripes in the primaries (outer webs) and I recall seeing primary tips that were mostly white with at least two narrow pale gray subterminal bands on the perched bird. The comparison of primary pattern with that typical of Thayer's in the above description is a comparison of the pattern only, not the shade of gray/black on the primaries. This individual had very pale gray that I would suggest is well outside the range shown by Thayer's (up to 15% of Thayer's can show gray rather than black in the primaries). The amount of gray in the primaries was also obviously less than typically shown by Thayer's (whether it is black or gray) with fewer primaries showing gray and narrower gray bands acro!
ss the primary tips.
It had a very short and narrow bill with barely noticeable gonydeal bump, probably within the range for Thayer's but on the short/petite end of the spectrum. The head was rounded with a steep forehead and large eye set well forward on the head. The body shape was only seen in flight by Lisa and it appeared deep chested. Lisa also observed the wide based wings typical of Iceland Gull when it flew directly overhead. The yellow iris, pink legs, and very pale mantle were all typical of Iceland as well.
Field marks we missed include primary extension, leg length, and structure of the perched bird. Because of the angle at which it was laying we were looking at the hind end of the bird and were thus unable to evaluate body shape and length of primary extension beyond the tail. The bird stood for short periods at which time we neglected to evaluate leg length.
|Song or call & method of delivery:||N/A|
|Behavior:||When we first arrived the bird was roosting on the ice (laying down)with bill tucked under its wing. It was quite close to several California Gulls (maybe four or five feet away) and there were Ring-billed and Herring Gulls in the immediate area, but not as close as the CAGUs. The bird stood up a couple times and lifted its head to look around several times when it did not stand up. It stretched its wing once when standing. Eventually it stood up while I was watching through the scope, ran a few steps and took flight along with many of the gulls on the ice. It flew directly towards us, flew over our heads and proceeded into the landfill with a group of CAGUs. In flight Lisa watched the bird with binocs and I watched through the scope. when it got close to us I lost track of the bird and was unable to find it among the other gulls. After it flew over our heads I found it with binocs and watched it fly into the landfill and disappear in the thousands of other gulls present. Lisa watched the bird fly directly over our heads through binocs.|
|Habitat:||Frozen pond near landfill.|
were they eliminated:
The gray mantle with white wing tips eliminates all other large gulls except
Glaucous and hybrids with Glaucous. I suppose Thayer's should be considered just
for the sake of being thorough.
Thayer's Gull typically has black wing tips but a minority have gray. The gray on this individual was much too pale for a Thayer's, being very difficult to see even through the spotting scope. The extent of gray markings in the primaries was outside the range for Thayer's, being limited to out webs and a few narrow subterminal bars. The wide based wings, sharply tapered primaries, yellow iris, and crisp head streaking provide further points against Thayer's.
Glaucous is much larger with flat head/squared off fore- and hind-crown, pure white wing tips with no gray markings, and a long heavy bill with obvious gonydeal bulge.
Any hybrid combination with Glaucous would also be larger than this individual. It is well outside the range of variation for Glaucous Gull, even a small petite "barrovianus" which would still have a squared off head and larger bill than this individual has.
Hybrids between Glaucous and any black winged species would have much darker gray in the wing tips, darker mantle shade(except for Herring x Glaucous), and more extensive gray markings in the primaries.
Glaucous x Glaucous-winged would be larger with longer and heavier bill, darker mantle shade, and more extensive gray markings in the primaries, although the color of the gray could probably match that of this individual.
All the field marks observed on this bird are consistent with, and typical of, Iceland Gull. There are no traits that fall near the extreme of variation within the species. No field marks were observed that raise even the slightest concern about this individual being another species, a hybrid with Thayer's, or any other hybrid combination.
this & similar species:
|I've seen Iceland Gull on three previous occasions. I have studied gulls seriously for about the past 10 years and annually observe thousands of Ring-billed and California Gull, plus hundreds of Herrings and a few Thayer's annually.|
|Description from:||Notes made later|
|Observer's address:||4125 Beaver Springs Rd.|
|Observer's e-mail address:||firstname.lastname@example.org|
|Other observers who independently identified this bird:||Lisa Weisse, contact info as above.|
|Date prepared:||23 January 2011|
Lisa and I looked at the photo of an adult
taken yesterday [1 Feb 2011]at Farmington Bay by Tim Avery,
and we both agree that it looks very much like the bird we saw at Lee Kay on 3 January 2011, UBRC #2011-06. I just reread our description and the primary pattern shown by this individual matches what we described quite well. Obviously I can say with 100% certainty but it seems likely that the bird photographed by Tim is the same individual. If not at least it matches our description very well.
was an adult gull photographed by Cameron Cox at Farmington Bay on 20 January
2011 the he identified as an Iceland Gull.
My camera was broken so I was unable to get any photos as I usually do.