17 February 2016

Black-back Bonanza - Chandeleur, Great Lakes and Slaty-backed Gull

I stopped at the Arsenal Road Pond in Willmington, Illinois on Monday (15 February 2016) and was blown away by the gull diversity - 9 species and 2 hybrids, by far my best day of the season:

Chandeleur Gull (putative Kelp x Herring; adult)
Great Lakes Gull (putative Great Black-backed x Herring; adult)
Slaty-backed Gull (adult)
Great Black-backed Gull (2nd cycle)
Lesser Black-backed Gull (4 - 1 adult, 1 third cycle, 2 first cycle)
Herring Gull (800+)
Glaucous Gull (2 - adult, 1st cycle)
Kumlien's Gull (1 - adult)
Thayer's Gull (6 - 4 adults, 2 second cycle)
California Gull (2nd cycle)
Ring-billed Gull (175)

The putative Kelp x Herring hybrid is no other than "Gull Nasty", the Michigan City bird that has frequented the Indiana/Michigan lakefront for the last several winters.

Chandeleur Gull (Kelp x Herring hybrid). 1st time observed in Illinois.

Ken Brock tells me the bird went absent in early January, and now we know it's enjoying some time at the landfill some 70 miles to the southwest in Will County, Illinois. I last saw this individual in New Buffalo, Michigan back in early October.

Also of interest is the continuing adult Slaty-backed Gull that seems to not like showing itself on weekends:

Slaty-backed Gull (adult). 1st Will County, Illinois record.

Most of the pond was iced up with a small stretch of open water near the parking lot, and the Slaty finally came in close enough for these photos:

String-of-pearls on p6-p8. No mirror on p9.

Chandeleur Gull (far left) & Slaty-backed Gull (far right at rest).

The adult Great Lakes Gull (pink legs, thin white tips to the inner primaries) made a brief, but distant, appearance too, and for a brief moment I considered the possibility of a 2nd Slaty-backed Gull. I mentioned on North American Gulls that I pity the novice that shows up here trying to hastefully check off a SBGU - I meant that, literally. The black-backs here, especially when viewed at a distance are lots of "fun" to sort through.

Some lighter stuff:

2nd Cycle Thayer's.
Extreme pale-end Herring Gull (2nd cycle).


  1. Amar, I am happy that I came upon your blog. It's really important. Years ago a friend commented to me "gulls and I don't speak." I agreed. I think you're going a long way to helping people like me speak with gulls. Your birds and photos are really interesting.

    1. Thanks for the feedback, Cathy, and thanks for reading.

  2. Other than the leg color, is there any way to seperate Slaty-backed from Lesser Black-backed? They look almost identical.

    1. From a distance it wouldn't be a very easy distinction. Adult Slaty-backeds will generally show a more "plump" jizz and a wider tertial crescent and broad white secondary skirt - but not always! Slaty-bakcs also have shorter wing projections than a Lesser, when at rest. Also, I've never seen an adult Slaty with a large red gonys spot on the bill like many adult LBBGs do. Ideally though, if you think you have an adult SBGU, you'd want to stay with it until you can make out leg color and study the open wing. Hope that helps. AA