Slaty-backed Gull
Larus schistisagus

 

 

All 2013 photos on this page are of a single, adult Slaty-backed Gull, discovered and identified by Beth Olson, Skye Haas and me, in Marquette, Michigan, on 16 March 2013. This is the third record for Michigan of Slaty-backed Gull, and only the second for the Upper Peninsula of this Asian species. In other words, proper documentation is crucial. On this page, I have provided a chronological photographic record of this birdŐs stay in Marquette, as well as a bit of commentary on field marks (when appropriate). Here is a link to a story, with video, that a local news station (TV 6, Fox UP) did on this bird (this segment on TV 6 was named by the reporter as his favorite story during his stint here in the U.P., as you can read here).

 

 

16 March 2013, Picnic Rocks. First view, just coming off the ice, in flight, toward us (our first look at this bird in flight; a dramatic moment). Here is a view of this bird as it flew past us (note especially broad trailing edge and heavy neck mottling, broad window on P10 and slightly smaller window on P9); and here is another. Here is shot of this bird on the ice, before it took flight (note adult Iceland Gull at far left).

 

17 March 2013, Picnic Rocks. First view, good but distant view of the Ňstring of pearlsÓ in the outer primaries (i.e., white tongues on P6–P8). Here is another view of this bird (with Iceland, Glaucous and Herring Gulls); note especially the bright pink legs.

 

24 March 2013, Lower Harbor. First view, note the birdŐs bulky size, black outer primaries versus slate-colored back, white wingtip patterns (as above), and broad trailing edge. Here is another view of this bird (note same features as in previous shot, especially the Ňstring of pearlsÓ on P6–P8).

 

29 March 2013, South Beach. First view, distant shot, but good view of slate-colored mantle and reddish/pinkish legs; also good size comparison with adjacent Herring Gull.

 

6 April 2013, South Beach. First view; note especially bill structure (stout with parallel edges) and pink legs.

 

 

Another Slaty-backed Gull appeared in Marquette on 31 March 2014. Perhaps it is the same bird as the 2013 bird?

 

2 April 2014, South Beach. First view; note especially the Ňstring of pearlsÓ, the large white trailing edge to the secondaries, the bulky size (in comparison to the nearby Herring Gulls), and the dark (pink) legs.

 

5 April 2014, FounderŐs Landing. The Big Lake was almost completely iced over, so I walked out a few hundred yards on the ice to get this photo (taken at great distance); note especially the Ňstring of pearlsÓ, the large white trailing edge to the secondaries, the bulky size (in comparison to the three Herring Gulls), and the billŐs stout parallel edges. Here is another shot of this bird out on the ice (again, taken at great distance); note the same features as in the previous photo.

 

 

A Slaty-backed Gull appeared in Marquette in late March 2015. I feel confident that this is the same bird as in the previous two years (age is right, structure is right, size is right, time of year is right). I first observed and photographed this bird on 23 March, and my last sighting of this bird was on 28 March. Inexplicably, my camera settings were off for this entire week, and so all of my photos of the gull this year are over-exposed, and hence, vastly crummy. Still, I include two photos, for the record.

 

23 March 2015, South Beach. First view, note bill structure (stout with parallel edges), slate-colored mantle; also good size comparison with adjacent Herring Gulls.

 

24 March 2015, Picnic Rocks. Another view; note bill structure (stout with parallel edges), slate-colored mantle and reddish/pinkish legs; also good size comparison with adjacent Herring Gull.

 

 

Late in the afternoon of 27 November 2015, I found a dark-backed gull in MarquetteŐs Lower Harbor, rafting with a large group of Herring Gulls. My oldest son, Jack, and I watched and photographed this bird for about one hour. During that time, this gull did not fly or even extend its wings (so of course, we did not see its legs). This was clearly an adult gull. It was roughly the same size as the nearby Herring Gulls, but a bit bulkier. Its back was dark, but not black, slightly lighter than the black primary tips ("slaty" describes the color well). Its bill was stout, with parallel edges. Its head and neck were quite streaked. It had a broad white secondaries skirt. This fits perfectly with Slaty-backed Gull. The other N. American dark-backed gulls can be eliminated as follows: this gull is far too small to be a Great Black-backed Gull (to say nothing of its too small bill and its head and neck streaking); this gull is too large to be a Lesser Black-backed Gull (to say nothing of its very dark back); this gullŐs bill isnŐt large enough to be a Western Gull (to say nothing of the fact that Western Gull is vanishingly rare away from the west coast); and Yellow-footed Gull is just insane. There follows two (crummy) photos I made of this gull:

 

First view.

 

Second view.