Western Grebe, Aechmophorus occidentalis
The extension of the black crown over the eye and the greenish color of the bill identify this as a Western rather than a Clark's Grebe, and the narrow and slightly upturned shape of the bill mean it is a female.
The Western Grebe, front, has the greenish bill and eye within the black crown, the Clark's, rear, has an orange bill and the eye
in the white, also more white on the flanks. Western and Clark's Grebes were recognized as separate species only in 1985. These birds clearly show the main differences between the two species. In other cases, birds have intermediate bill color and/or facial pattern;
these can be hybrids or less typical individuals of one of the two similar species. Birds in non-breeding plumage make for more identification difficulties.
Above, a Western Grebe with the typical facial pattern, but with bill color somewhat intermediate between greenish and orange. This bird's bill is especially thick, making it easy to identify the bird as a male; contrast the bird pictured at the top of the page, an equally extreme example of female bill shape.
We had nesting Western Grebes on Coyote Lake in Spring 2013, a rare chance
to see the spectacular courtship rituals of this species in the San Francisco Bay
Area. Above, the "weed-dancing" ritual, described in Birds of North America
Online thus: "When both birds have weeds, they approach, feet churning,
and rise into vertical posture with most or all of body out of water, necks
stretched upward, bills raised 20° to 80° above horizontal."
Here two courting birds engage in the famous rushing ceremony, in which "two birds turn to one side, lunge forward body completely out of water, and run rapidly across the surface side by side."
Here, a pair of Western Grebes copulates. Unfortunately, the attempts of several pairs of Western (and at least one pair of Clark's) Grebes to nest on Coyote Lake in Spring 2013 were unsuccessful, as the nests were abandoned without any young birds hatching and surviving.