Our Wayne County Slaty-Backed Gull returns in Full Breeding Regalia (May 2, 2015)

May 2nd, 2015 our Wayne County Slaty-Backed Gull returned to Grace Lake in Belleville.  I say 'returned' because I am assuming this is the same bird I saw in December, 2014 and others have seen a handful of times over the past two years.  Here's what I saw.  All photos are through my Kowa scope with my iPhone 5s.  This combo does a great job on distant birds.  Although resolution does get weak, the small sensor produces a great depth of field meaning a relatively high percentage of in focus shots.  The pictures are certainly not DSLR quality, but for documenting distant birds this works simply, quickly and very satisfactorily.

Note the dark backed gull (but not as dark as a Great-Blacked Gull) as large as the largest Herring Gulls, but with a full chested look, which together with a cool shadow over the eye gives it a powerful presence and and a 'don't mess with me' expression.  The primary extension looks long simultaneously giving it a sleek appearance.  Most striking, however is the extremely broad white crescent between the dark mantle/wings, and the black primaries.  This white is due to broad white on the tertials and the tips of the secondaries.  Although I believe the Michigan Bird Records Committee might not be able to accept this shot alone as conclusive, feeling they need an open wing shot, (and for what it's worth, I totally support whatever they feel is required for certainty), this bird is unmistakably a Slaty-Backed Gull to my eye.  It is quite striking having put on it's Spring attire. 

Striking Adult Slaty-Backed Gull in Alternate Plumage

Slaty-Backed Gull is a resident of NE Asia.  It has bred in Western Alaska, and regularly occupies coastal Alaska in the off season.  My impression is that winter records of Slaty-Backed Gull outside of Alaska are on the increase, but I have not researched this.  The Michigan Bird Records Committee website currently lists 3 previous records of Slaty-Backed Gull in Michigan.  In fact, with the notable exception of a Slaty-Backed currently being seen in Seattle, ours may be the only May record in the lower 48 States - certainly one of the few.  Wow!!  How cool is that!

Here was also one of the first views; sitting with a Lesser Black-Backed Gull.  Note it is much larger, especially noticeable in the head and bill.  The structure and posture is not at all like the LBBG.

The Slaty-Backed dwarfs a Lesser Black-Backed Gull

Below are a couple of shots of "the" Slaty-Backed on December 28, 2014, also at Grace Lake.  (I assume it is the same bird, but obviously can't be sure.).  Note the winter plumage, especially the streaked head and neck.  The very broad "Tertial Crescent" is present in this plumage as well as in alternate plumage.

Winter Plumage with Herrings and Great Black-Backed Gulls

Fun Comparison with both Lesser and Great Black-Backs

The two main field marks not yet visible are 1. Pink legs and feet, and 2.  The proverbial 'String of Pearls' on the spread primaries.  Happily this time, it obliged my iPhone and gave me some opportunities.  First, the Pink legs and feet (and also the "pearls")

But here you can see the String of Pearls on both upper-wing and under-wing.  Note the broad white trailing edge to the wing, adding to the "tertial crescent" mentioned above.

This completes all the field marks I know of.  I feel UNBELIEVABLY lucky, blessed if you will, to have gotten to see and photograph this wonderful rarity TWICE and in both summer and winter plumages.  Given a Slaty-Backed was seen last year as well (at Crosswinds Marsh by ?), I am hopeful we will get more chances next year!