Idaho Bird Records Committee Rarities Report Form

Use a separate sheet if necessary to continue comments.

Mail this report to Shirley Sturts, Secretary, Idaho Bird Records Committee

4887 Fernan Lake Road, Coeur d'Alene, ID 83814

Species: Glaucous-winged Gull

Reporter: (include address, phone, e-mail)

Lisa Hardy

819 W. Park Ave.

Kellogg, ID 83837

basalt@earthlink.net
Other Observers:

none

Date Report Prepared: 11/25/2011
Date Sighting Occurred: 11/24/2011

Locality of Observation: Anderson Lake, near Harrison, Kootenai County, ID
Habitat: freshwater lake
Conditions: cloudy, 45 degrees F, little or no wind

Did you take notes…

during the observation? ____________

after the observation? ____X__________

the same day? ____________________

another day?______________________

not at all? ________________________

Did you consult a field guide or other reference work?

during the observation?____________

later the same day? ______X_________

another day? _____________________

not at all? ________________________

What guide(s) or reference(s) did you consult? Gulls of North America, Europe and Asia, Olsen & Larsson; Gulls of the Americas, Howell & Dunn

Description: I had finished studying a juvenile GLGU and turned to scan farher along the shoreline with my scope. This bird was an immature gull, but did not look familiar. It was noticeably darker than the GLGU, but not as dark as an immature CAGU, nor as contrasty as an im RBGU, making me think next of a first-winter HEGU. The bird was facing towards me, but it seemed that the primaries were light-colored, i.e., I was unable to see any feathers toward the rear which were darker than the overall mantle/scapular coloring of dingy white and brownish. I waited for a number of minutes for it to change position so I could get a better look, to no avail. The eye appeared dark, and the bill uniformly dark.

I left, and when I returned 10 minutes later, the bird took flight, and I was able to track it with my binoculars, noting pale, translucent flight feathers of the wing contrasting with the darker coverts, from both above and below. The primaries were uniformly pale and unmarked.

I was not able to judge its size as there were no gulls or ducks nearby, but it seemed a slow, heavy takeoff, which gave me the impression that it was one of the larger gulls.
Behavior: Standing in water up to its belly.

How and when did you positively identify the bird, and what clinched the identification for you? Positively identify is perhaps too strong a characterization; rather a combination of features suggest that GWGU is the most likely identification.
How did you eliminate similar species, and what were they? Pale primaries eliminate other gulls except Glaucous and Iceland. Bill coloring eliminates Glaucous and is unlikely for Iceland. If a hybrid, it would not be one of the more usual hybrids - most hybrids also eliminated by above two criteria. Iceland/Kumlien's perhaps not completely eliminated as size/structure was difficult to judge due to distance, the head-on view, and the bird's standing belly-deep in water.

Experience with this species (and similar species): I have seen many GWGU x WEGU hybrids on the coast of Washington and BC; a few that appeared to be fairly "pure" GWGU.
General birding experience: intermediate

Were photo(s), video, and/or audio obtained by you? (If yes, please include or attach) Two photos attached, cropped from originals. These are really pathetic pictures, but they show overall coloration and the dark bill.

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