Caspian

 Caspian Gull

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Here are the key features
for a standing bird

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1 .. Long legged with extra length on tibia
2 .. High & protruding breast
3 .. Long slender bill without much gonys angle
4 .. Small pear-shaped white head
5 .. Dark small beady eye
6 .. Fine streaks make a neck scarf
7 .. Mantle & Scapulars, often diamonds with dark shafts occasionally anchor bases
8 .. Tertials, narrow borders not notched with broad tip and solid dark centers
9 .. Greater coverts, fine pattern on solid base not chequered
10 .. Dropped ventral bulge


Here are the key features 
for a bird in-flight showing
the upperwing

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1 .. Greater coverts, mid brown, solid outer with fine white pattern inner, tipped white
2 .. Long slender bill without much gonys angle
3 .. Fine streaks make a neck scarf
4 .. Uppertail coverts white, pale brown markings
5 .. Solid dark tail band, finely barred towards upper
6 .. Dark trailing edge 
7 .. Venetian blind effect, dark outer web, light inner
8 .. Hockey stick ends 

Here are the key features
 for a bird in-flight showing
the underwing

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1 .. Fine streaks, neck scarf prominent in flight
2 .. White area near Alula, prominent in flight
3 .. Pale underwing
4 .. Axillaries fine pale bars
5 .. Dark tail band prominent in flight

Tail features close-up

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Uppertail
Dark solid tail band, finely barred towards upper
Tail coverts with pear shaped sub-terminal marks
More heavily marked on rump

Undertail
Dark tail band still prominent and fine barring
Tail coverts spotted with dark markings

Images comparing the dorsal view of Caspian in-flight

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Images comparing the underwing pattern in-flight of Caspian

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Images comparing the Caspian wing patterns ..

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Images comparing Caspian tail patterns ..

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 Some comparison images showing the variation in 1st. W Caspian Gull ..

Three individuals showing colour & pattern marking variations ..

At slightly different stages of moult & wear ..