Greater Scaup (Aythya marila), Kiwanis Park Lake, Maricopa County

This Greater Scaup was discovered and photographed by Pierre Deviche on 27 December 2008 at Kiwanis Park in Tempe. 

Although regular in winter in the Lower Colorado River Valley, Greater Scaup is a rare winter visitor to the rest of the state.  It is difficult to identify and may be overlooked.  The third photo in this set provides a nice comparison of Greater and Lesser Scaup in relaxed swimming posture.  The differences in head shape and bill size are particularly obvious. 

This is a Greater Scaup because of the consistently round head, relatively large bill with wide black nail at tip. White in wings during flapping extends to proximal primaries. Usually Greater Scaup has whiter flanks than Lesser.  The relatively gray flanks of this individual may suggest that this is a hatch-year male.

27 December 2008, photo by Pierre Deviche

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