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English and Scientific names: |
Great
Black-backed Gull (Larus marinus)
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Number of individuals: |
1 near-adult; probable 3rd basic |
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Locality: LOUISIANA: |
Jefferson Parish |
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Specific Locality: |
Grand Isle; shell road by Exxon fields |
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Date(s) when observed: |
13 April, 2007 |
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Time(s) of day when
observed: |
5:45-6:00 p.m. |
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Reporting observer and address: |
Phillip Wallace New Orleans, LA |
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Other observers accompanying reporter who
also identified the bird(s): |
Curt Sorrells |
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Other
observers who independently identified the bird(s): |
Devin and Justin Bosler, and other observers at Grand Isle Migratory Bird Festival |
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Light
conditions (position of bird in relation to shade and to direction and amount
of light): |
Good light; sun low at
right angle to line of sight. |
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Optical equipment: |
Zeiss 10x40 bins |
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Distance to
bird(s): |
15-25 m |
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Duration of
observation: |
15 minutes |
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Habitat: |
Shell road adjacent to collecting pond and open fields; 200-300 m from the gulf |
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Behavior of bird: |
Feeding; agonistic behavior toward other gulls; flying. |
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Description: |
Larger than adjacent Herring Gulls but not especially large for the species. White underparts and head. Sparse dark streaks on nape. Tail white except for small grayish-black smudge on tail. Black mantle and back. Wings same black color as mantle except for some brownish tinge to primaries and primary coverts; one white mirror on P10. Large, blocky head. Legs pinkish with some ivory tones. Large bill yellowish with red and black smudge at tip. Iris pale but not as pale as full adult. |
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Voice: |
Vocalized twice. Voice lower than Herring Gull. |
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Similar
species: |
Size, black back, and pinkish legs rule out all other gulls. |
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Photographs
or tape recordings obtained? |
Stills grabbed from video accompany this report; video submitted to LBRC. |
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Previous
experience with this species: |
I've seen numerous times in LA and on east coast. |
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Identification aids: |
None |
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This description is written from: |
Notes written at 8:30 p.m. on 13 April and from video. |
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Are
you positive of your identification? If not, explain: |
Yes. |
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Reporter: |
Phillip Wallace
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Date and time: |
9 June, 2007 |