Greater Scaup (Aythya marila), Green Valley Water Treatment Facility, Pima County

Mark Stevenson discovered a Greater Scaup at Green Valley Sewage Ponds on 4 December 2008.  Laurens Halsey, while looking for the original, discovered two additional Greater Scaup and photographed all three on 6 and 7 December 2008.

Greater Scaup is a casual winter visitor to Southeastern Arizona.

The first photo shows all three Greaters.  From front to back: an adult female (bright yellow eye), an immature male (some gray vermiculated back feathers) and an immature female (no gray feathers).  On all three note the rounded head profile, variably white auricular edge and large bills with large, broad nails at the end.   In the third photo, note the Lesser Scaup with characteristic head profile in the background. 

06 and 07 December 2008, photos by Laurens Halsey