Slaty-backed Gull in St. Louis County
2010-12-19

'Casual' in Minnesota - Five or fewer records in St. Louis County for the Winter season

At 11:01 am this morning, I spotted an adult Slaty-backed Gull in flight over the Superior Landfill, Douglas Co., WI, and then around 11:40 am this bird was found at Canal Park in Duluth by Peder Svingen. When I joined Peder at Canal Park around 1:45 pm, the bird was incredibly tame and we got great photos, one of which is shown here. This could well be the same third-cycle bird seen last fall 28 October-13 December 2009 at this same location, now in adult plumage. Note the "string of pearls" present on both the upper and underwing, which is formed by white subterminal tongue tips on the outer primaries, most distinctively on P8. Also note the dark pink legs, yellow eyes, moderate head streaking, and white white trailing edge to the wing, especially along the outer secondaries. Since Slaty-backed Gull hybridizes with mutliple other gull species (Herring, Glaucous, Glaucous-winged), and other dark-mantled hybrid of non-Slaty-backed parentage can appear superficially similar to pure Slaty-backed, care was take to eliminate these potential hybrid pitfalls.

Karl J. Bardon