Although Cassin's Vireo (Vireo cassinii) is described as a "fairly common summer resident and fall migrant" in Sonoma County (Bolander and Parmeter 2000), it's considered a rare migrant on Bodega Head.
In both of these images, look for the bold white "spectacles," gray head and face, olive-green back, white underparts with hints of yellow, and two white wing bars.
The vireo was foraging among the Myoporum shrubs. It caught at least one moth and a caterpillar (see below).
In the image above, the vireo is holding an inchworm against the branch with its right foot. Initially the vireo had picked up the caterpillar with its bill, but then it placed it on the branch and held it there before eventually picking it up again and swallowing it.
Here's a quick trivia question related to this vireo's name. It honors John Cassin, a 19th century ornithologist who wrote one of the first major accounts of birds in the western U.S. Do you know how many other birds were named after him? That is, how many other birds can you think of with "Cassin's" in their name? The answer is below the next image.
Answer: Four other birds were named after John Cassin: Cassin's Auklet, Cassin's Finch, Cassin's Kingbird, and Cassin's Sparrow.