Mongolian Gulls Larus (?) mongolicus
December
9th 2006 Shanghai China

Photos of 7 adults were available to check primary-pattern out of hundreds of photos we took on the day. Their characteristics such as molt timing, primary pattern and amount of streaks showed very wide range beyond our expectation. But all birds seemed reasonable to consider as Mongolian Gull, by their combinations of plural characteristics.

Number of
black-marked primaries

6

7

9+?

Number of birds

2

4

1

Percentage

29%

57%

14%


Individual 1






6 black-marked primaries.


Individual 2






6 black-marked primaries. The P8 is still the longest. The primary pattern that shows extensive white resembles Caspian Gull. An unusual example of Mongolian Gull?


Individual 3




7 black-marked primaries. The head streaking is extensive for Mongolian Gull, but is thinner and sharper than most Vega Gulls in Japan.


Individual 4




7 black-marked primaries.


The right is the "Individual 1"


Individual 5




9+?? black-marked primaries. By the way, how many primaries does this have??

An example of unusual individual (taimyrensis) with 11primaries photographed in Japan



Individual 6


7 black-marked primaries.


Individual 7


7 black-marked primaries. The latest-molter on this trip matching average Vega Gulls in Japan. The P7 is the longest. Other features seemed typical for Mongolian Gull.






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