Verification of Unusual
Rec. # 2008-33
Lesser Black-backed Gull
|Scientific name:||Larus fuscus|
|Date:||17 April 2008|
|Length of time observed:||5-10 minutes|
|Location:||"Sue's Ponds", just west of the Logan Landfill, Logan|
|Elevation:||about 4500 feet|
|Distance to bird:||~20 yards|
|Optical equipment:||Nikon Monarch 10x42 binoculars, Nikon 20x Sky and Earth spotting scope, Nikon D80 with 80-200mm f/2.8 lens|
|Light Conditions:||direct overhead sunlight|
|Description: Size of bird:||About the size of California Gulls nearby|
|(Description:) Basic Shape:||Gull shape - approximate proportions of California Gulls|
|(Description:) Overall Pattern:||Gray mantle and scapulars, brownish wings with gray spots, white base color to body with brown flecking, pale yellow legs, dark primaries and tail|
|(Description:) Bill Type:||Gull bill, perhaps slightly more robust than that of the California Gulls, mostly dark but pale at base of lower mandible and upper mandible.|
Field Marks and
This gull was about the size of the California Gulls around it. It was
identified as a second-winter bird on the basis of its gray mantle and scapulars
with otherwise brownish patterning typical of a first-winter gull. The brown
speckling/smudging in its white parts indicates that it has not yet reached
The bird had yellow eyes, most clearly visible in photos A and B. The legs were pale yellow, but distinctly yellow (i.e., not pinkish). The yellow color of the feet is most visible in the photos of the bird flying (G and H), but can also be seen in the standing photos. The bill was dark at its tip and pale at its base, gradually changing tone in between, with the dark reaching further back along the tomia and culmen. The head feathering around the eye was darker than the surrounding head, giving the typical punched-in-the-eye look of this species. The head and body were white with brown patterning in the lower breast and upper belly, and on the lower nape and sides of the upper breast. The upper breast was clean white. The mantle was darker gray than in the California Gulls but not as dark as a Slaty-backed, Western, or Great Black-backed Gull. The mantle color in some photos appears nearly concolor with that of the Californias (e.g. photos B and C) but in others app!
ears much darker than the Californias (e.g. photo D).
The primaries were black and projected well beyond the tail when folded. They did not have visible white apical spots. In flight, the outer primaries were solidly dark and the inner primaries were slightly less dark, but were not pale enough to give the impression of a pale window as in a Herring Gull. The secondaries were dark and were set off from their coverts. The tail in flight was white at its base with a very dark terminal band.
|Song or call & method of delivery:||None known to come from this individual.|
|Behavior:||Loafing with other gulls, primarily California Gulls and some Herring Gulls.|
|Habitat:||Shallow pond on mudflat designed as shorebird habitat. Surrounding area is largely agricultural, with the Logan Landfill just across the road to the west.|
were they eliminated:
California Gulls were present for direct comparison. They have paler mantles
than this individual and dark eyes. They also have a small pale panel on the
inner primaries and a more distinctly bicolored bill without black on the base
of the culmen or the base of the tomia.
Herring Gulls are generally larger than this gull, which was about the same size as the California Gulls around it. Herring Gulls have a paler mantle, and a pale panel in the inner primaries in flight. Herring Gull legs are pink, not yellow,
Western Gulls are larger than this bird, have a more robust bill, and pink legs.
Yellow-footed Gulls are similar in many ways but have a much more robust bill than this individual.
Slaty-backed Gulls are larger than this species and have pink legs and a pale panel on the inner primaries.
this & similar species:
|I have extensive experience with the common gull species of the area, including California Gulls and Herring Gulls. This was my first observation of a Lesser Black-backed Gull, although I didn't know it at the time (see notes). I have also seen many Western Gulls in Washington and Great Black-backed Gulls in New Hampshire, where I used to live.|
|References consulted:||Sibley Guide to Birds, National Geographic Field Guide to the Birds of Western North America, and Howell and Dunn's Gulls of the Americas|
|Observer:||Ryan P. O'Donnell|
|Observer's address:||1098 Crescent Dr., Logan, UT|
|Observer's e-mail address:||Ryan@biology.usu.edu|
|Other observers who independently identified this bird:||None known to me.|
|Date prepared:||13 Nov 2008|
|Additional Comments:||In the field, I noticed that this bird was different from the others but back home when reviewing the photographs I decided it was unidentifiable with my level of knowledge at the time. It didn't seem to fit any of the species I was familiar with, but I didn't know what it was. Last week I saw and identified what was to me my first Lesser Black-backed Gull (see record #2008-32). By coincidence, I was going back through some old photographs yesterday and recognized this gull in my photographs as a Lesser Black-backed Gull, a species I had probably not considered at the time I photographed it.|