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Ornithological Studies Presentation
Large Alcids
by Paul Guris 01/03
|
Razorbill |
Thick-billed Murre |
Common Murre |
|
|
Bill |
Deep, stout bill with white band around the middle, flattened side to side. 1st winter bill smaller but still deep, with no white band. | Shortish and stout, with decurved culmen, noticeable gonydeal angle, whitish line along upper gape. 1st winter somewhat smaller, with limited white gape line. | Long, straight, slender, and pointed. Warning: can occassionally show paleish gape line. |
|
Head
& Neck (winter) |
Lower face white, upper dark with white rising behind eye. Dark, rough line from eye. Nape dark. Sides of neck mostly white. | Lower face white, upper dark with no white above the eye. Nape and sides of neck dark. | Lower face white, upper dark with white rising behind eye. Thin, clean line from eye. Nape mostly dark with white wrapping up from sides of neck. |
|
Head
& Neck (summer) |
All dark with white coming to a rounded point on the foreneck. White line from bill to eye. | All dark with white coming to a sharp point on the foreneck. | All dark with white coming to a rounded point on the foreneck. |
|
Upperparts |
Black. | Black. | Often browner than the others, but varies with population and age. |
|
Underparts |
White. | White. | White, often with darkish streaks on flanks. |
|
Underwing |
“Wingpit” white. | “Wingpit” white. | “Wingpit” dusky. |
|
Swimming
Profile |
Large bill, often tilted up. Large head and thick neck. Long tail often cocked up. | Short stout bill usually held level. Blocky head, “neckless” look, and short rear end. | Long, thin bill sometimes held up. Small head, thin neck, and short rear end. |
|
Flight
Profile |
Streamlined body, with thick neck, and blunt front end. Long pointed tail covers the feet. | Hunchbacked body, “neckless” look, with bill pointed slightly down, and rear end “dumpy”. Short, blunt tail usually does not cover feet. | Slightly hunchbacked body, thinner head and neck than Thick-billed, rear end “dumpy”. Short, blunt tail usually does not cover feet. |
|
Rump
|
Much white showing on top. | Much white showing on top. | Little white showing on top. |
|
Spring
Molt |
Not sure. | Seems to fill in across chest first and onto throat last, often (always?) creating a partial breast band. Dark fills in evenly. | Fills in with spotting on throat and chin. Shows vestiges of winter pattern well into its molt. |
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