This is one of the largest and heaviest of North American birds. Weights of up to 30 lbs have been claimed. According to the "Birds of North America" account, this species has a Supplemental Plumage in which the crown and nape plumes are shed and replaced by short medium to dark grayish feathers on crown (and nape on some individuals); crown plumage highly variable among individuals. The National Geographic Field Guide illustrates this plumage with the label "chick feeding." The features are acquired after the chicks hatch, but appears on adults such as these, that have failed to breed as well.
This small group, was part of a flock of about 75 resting and preening birds with additional individuals and flocks seen in flight. It is suspected that these are probably failed breeders, or birds who have decided not to breed at all for whatever reason. The Far West is suffering from a drought and it is possible that some wetland breeding areas have dried up. This species does not breed here, but is a migrant and winter visitor to the San Francisco Bay area.
Panasonic DMC-LZ5 / Nikon FS 3 / 30XWA / hand-held, no adapter.