Common Goldeneye in St. Louis County
2010-02-02

Common in St. Louis County in the Winter season

Probable Common Goldeneye x Barrow's Goldeneye hybrid (COGO x BAGO) at Canal Park, Duluth, Minnesota, 2 February 2010. This individual's head shape and facial crescent appear to be intermediate between these two species. Its head shape is more triangular-shaped than is typical for BAGO, but at the same time it lacks the forecrown peak and steep forehead of an adult male BAGO. The shape of its facial crescent also appears to be intermediate. The facial crescent of Barrow's normally extends like the tip of a scimitar to a point above eye level. This apparent hybrid shows extensive white in its scapulars, which is more characteristic of COGO, and it lacks the black shoulder spur ("black boa") of adult male BAGO. Bill characteristics are difficult to judge in this single image, but the bill of BAGO is typically more "stout", i.e., shorter and deeper at the base, compared to the bill of COGO. None of these hybrid characters were noted on the drake BAGO photographed by Erik Bruhnke at 21st Ave East, Duluth, 22 November 2009 http://www.pbase.com/birdfedr/image/119670548 and at Leif Erickson Park, Duluth 3 January 2010 http://moumn.org/cgi-bin/recent.pl?rec_id=885 A probable hybrid male COGO x BAGO was studied by Jim Mattsson and others at Point Douglas, Washington County, Minnesota, 1 January 2008 (Loon 80:134). Neither Jim nor I are aware of any other reports of this hybrid combination in Minnesota. Comments are most welcome!

Photo by Peder H. Svingen, Nikon Coolpix P80, f5.6, ISO 64. Please see additional images of this bird at http://www.flickr.com/photos/cochon/sets/72157623339120658/