Herring Gull in St. Louis County
2013-12-08

Common in St. Louis County in the Winter season

This adult gull was observed on 8 December 2013 at Canal Park, Duluth by Mike Hendrickson, Peder Svingen and myself, and we believe it may represent an adult Vega Gull, an East Asian subspecies of Herring Gull (Larus argentatus vegae) that has a limited range in western Alaska, and has accepted records in at least Florida, Texas and Ontario, with the possibility of it being split as a distinct species. Some authorities already consider it a separate species, and it may actually be more closely related to Slaty-backed, with a similar range. Mike noticed this adult Herring Gull with a noticeably darker mantle than the surrounding gulls, but the mantle shade was clearly not dark enough for a pure Lesser Black-backed Gull (and clearly much paler than any dark-mantled species such as Slaty-backed or Great Black-backed). With overcast conditions, the mantle shade was quite striking and easily observed. We considered known hybrid combinations as we watched the bird (including Lesser Black-backed x Herring Gull, Great Black-backed X Herring Gull, Slaty-backed x Glaucous-winged Gull, Slaty-backed x Herring (Vega) Gull, Slaty-backed x Glaucous Gull), but none of these combinations seemed as likely as pure Vega Gull. Features distinguishing it from other possibilities include the mantle shade as discussed, dark yellowish-olive eye with considerable dark flecking (not clear yellow as North American smithsonianus Herring Gulls), bright red orbital ring (showing very well in the photos and studied with a scope at point blank range- North American Herring Gulls show yellowish to pale orangish orbital rings), pure pink legs identical to neighboring Herring Gulls (Lesser Black-backed hybrids would likely have some yellowish tones in the legs), bright yellow bill with red gonydeal spot and no dark markings, black on dorsal P10 and P9 extending all the way to primary coverts, black markings on outer primaries extending to P5 with black bar all the way across P5, subapical tongue tips on P6-P8 (similar to Slaty-backed Gull), very wide white trailing edge to wing dorsally (similar to Slaty-backed and unlike Lesser Black-backed, Great Black-backed, or North American Herring Gull), extensive head streaking especially around eye and nape, overall size and structure similar to adjacent Herring Gulls (perhaps even on the small side), and bill structure rather average for Herring Gull without the bulbous tipped look of larger species such as Great Black-backed and Glaucous-winged (and thus helping to eliminate hybrids with these two species). Furthermore, the black in the outer primaries was clearly pure black, which helps eliminate hybrids between Slaty-backed and Glaucous or Glaucous-winged (which would typically be at least a shade paler than pure black). Although we will do more research and seek confirmation from authorities familiar with this taxon, all traits seem to fit adult Vega Gull, which would represent the first documented record for Minnesota. Additional photos will be put at www.pbase.com/karlbardon.

Karl J. Bardon