Herring Gull (argentatus & argenteus)
(last update: February 11, 2013)
hybrid Glaucous-winged Gull x Glaucous Gull (glaucescens x hyperboreus) adult, December 28 2010, Clover Point - Victoria, BC. Picture: Jeremy Gatten.
These two species hybridise in northwestern North America (Swarth 1934, Strang 1977). The field characters of this hybrid combination are poorly known, but adults show wingtip patterns variably intermediate between the parent taxa (Strang 1977). Thus, some birds might resemble Kurnlien’s Gull in wingtip pattern (and upperpart tone). Given the parent species, however, this hybrid combination should differ noticeably from Kumlien’s Gull in its larger size and longer and heavier bill; this is certainly true of a few presumed Glaucous x Glaucous-winged hybrids seen wintering in California (Howell, pers. obs,).
In the bird below note the faded pattern on the wingtip and the pale iris.
