October 2016 Quiz

Age: The adult-like gray scapulars down the middle of the back and lightly marked uppertail coverts immediately suggest a 2nd cycle type. Also, the solid black tertials with relatively wide white edges support a bird not in its 1st plumage cycle.

Identification: The largely uniform brown wings and dark gray central scapulars point to a dark-backed species. The checkered lesser and median coverts are suggestive of Lesser Black-backed Gull. The lightly barred/marbled region in the tail feathers (specifically the partition between the black tail band and white uppertail coverts) also resembles LBBG, and that's what this month's quiz bird was identified as.

Berrien County, Michigan. September.

Here's a more detailed photo of this rather "large" Lesser:

Monthly Notables September 2016

• Sabine's Gull (adult type). Charlotte County, New Brunswick 02 September 2016.
• Continuing adult from late August, molting into basic plumage.
• Laughing Gull (2nd cycle type). Santa Barbara County, California. 02 September 2016.
• Continued from August.
• Little Gull (juvenile). Douglas County, Colorado. 03 September 2016.
• Stunning bird with 75%+ juvenile scapulars. Photos.
• Little Gull (juvenile). Polk County, Iowa. 03 September 2016.
• Black-legged Kittiwake (juvenile). Virginia Beach County, Virginia. 03 September 2016.
• Sabine's Gull (juvenile). Marathon County, Wisconsin. 07 September 2016.
• Sabine's Gull (juvenile). Jackson County, Missouri. 07 September 2016.
• Lesser Black-backed Gull (3rd cycle type). Coconino County, Arizona. 08 September 2016.
• Little Gull (juvenile). San Mateo County, California. 11 September 2016.
• Franklin's Gull (1st cycle). La Mitis County, Quebec. 12 September 2016.
• Lesser Black-backed Gull (adult type). Imperial County, California. 14 September 2016.
• Western Gull (2nd cycle). Washington County, Colorado. 16 September 2016.
• Continuing banded bird from Farallon Islands. Now in complete 2nd basic garb.
• Western Gull (juvenile). Salt Lake County, Utah. 13 September 2016. Photos.
• Glaucous Gull (2nd cycle type). Essex County, Ontario. 16 September 2016.
• Slaty-backed Gull (adult). Pierce County, Washington. 20 September 2016.
• California Gull (adult). Berrien County, Michigan. 21 September 2016.
• Laughing Gull (adult type). Morgan County, Colorado. 27 September 2016.
• Thayer's Gull (juvenile). Grand Forks County, North Dakota. 28 September 2016.
• A tad early. Still growing outer primaries. Photos.
• California Gull (2nd cycle). New Haven County, Connecticut. 29 September 2016.
• Possibly "the" 1st cycle bird seen back in April 2016 - a 1st state record then. Photos. 

Miscellaneous Notes

• Juvenile Sabine's Gulls made an above-average appearance throughout the western Great Lakes region this month. A handful of adults were recorded as well - not something that occurs annually! 
• Western Gull is now being reported with more frequency in the interior west. This movement away from the Pacific coast is augmented by the relative increase at the Salton Sea (a high count of 8 this month) and other inland bodies of water. The species is certainly on my radar and I feel it's only a matter of time before one strays to the Great Plains and east to the Mississippi River Valley.

September 2016 Quiz

The September bird appears to be a large 4-year gull. The trickiest part about this month's quiz - in my opinion - is correctly aging our gull. At first glance it looks like a 1st cycle, but a more careful look should reveal a 2nd cycle type. 

It's difficult to be sure what the true primary projection length is because those feathers are raised. But the projection does look suspiciously short, indicating the outer primaries are still growing. The tips are rounded which favors a 2nd cycle type over a 1st cycle. The newer, gray, central scapular feathers do resemble a 1st cycle type as they show dark marks along the shafts and some barring.

But scapular patterns are highly variable in large gulls and they can often betray a bird's true age. The wing coverts, on the other hand, are a bit more reliable when aging. Notice the obvious marbling pattern to the greater coverts and distal tertial edges. This is more typical of a 2nd cycle gull. Also notice in this images the rounded tips to the outermost primaries.

But what species? The bird is not very large or bulky. The relatively small and straight bill call to mind species such as California Gull, Lesser Black-backed Gull and Herring Gull.  

The paling iris and pink legs should immediately dismiss thoughts of a California Gull, and the relatively light gray scapulars raise doubts about this being a Lesser Black-backed Gull. I identified this month's bird as a retarded 2nd cycle type Herring Gull, photographed in Northern Illinois. January.