Gray-browed Brushfinch

Extremely similar to widespread Rufous Hummingbird; identical in plumage except for males' solid green back (which can be shown by Rufous too). Breeds only along a narrow strip of coastal California and southern Oregon. On females and immature males, the only way to separate them from Rufous is by the shape of the tail feathers, which is extremely difficult to determine without good photographs.

Small brownish-gray warbler with a grayer head and broad dark mask that sets off the white throat. Lacks bright rusty wing patch of Greater Whitethroat. Varies subtly across wide range. Found in scrubby habitats, especially dense hedges with thorny bushes and trees. Skulking and difficult to see well; often located by scratchy chortling song that ends with a distinctive loud rattle. Gives dry ticking calls.

Sub-tropical tern; slightly smaller than Common Tern with a lighter and less powerful flight, as well as a longer-billed and shorter-legged profile. In all plumages, note the darker upperparts, including the rump and uppertail. Adults have medium dark gray underparts with a dark underwing trailing edge, similar to the shorter-tailed Whiskered Tern. Note that in different light conditions, Common Tern also shows gray underparts, but Common Tern always has a white tail and rump. Young birds are very similar to Common Tern, but White-cheeked Terns are more strongly marked. Breeds on small islands and coral reefs. Vocalisations similar to Common Tern.