Thayer's Gull (Larus thayeri), Rotary Park, Mohave County

This Thayer's Gull was discovered and photographed by Lauren Harter and David Vander Pluym on 22 November 2010.

There are ten previous records, most along the Colorado River. 

Small gull with a dainty bill and rounded head. Pale-tipped, brown primaries contrasting with paler secondares.  Herring Gull would have a flatter head with a longer and more substantial bill, and black primaries without pale tips.  In flight the primaries have a diagnostic "venetian blind" effect: dark outer webs to the outer primaries and the pale inner webs. Finally, the underside of the primary tips are white.  Herring Gull would be brown or black.  Iceland Gull would have patterned tertials (these have solid centers) and primaries the same color as the secondaries. 

22 November 2010, photos by Lauren Harter

22 November 2010, photos by David Vander Pluym

All photos are copyrighted© by photographer